EX#16 5-19-2023 Final TIA Optimized
Traffic Impact Analysis
FOR
Ponderosa Ridge East
Spokane Valley, Washington
Final - May, 2023
2020-2798
TRAFFIC IMP ACT ANALYSIS
Ponderosa Ridge Phase II
(Spokane County)
AND
Ponderosa Ridge East
(City of Spokane Valley)
Updated For City of Spokane Valley
May 2023
Spokane Valley Project Number (SUB-2022-0002)
W.O. No. 2020-2798
Applicant:
Lanzce G Douglass Investments, LLC.
1402 E. Magnesium STE 202
Spokane, WA 99217
Prepared by :
Whipple Consulting Engineers, Inc.
21 S. Pines Road,
Spokane Valley, WA 99206
(509) 893-2617
This report has been prepared by the staff of Whipple Consulting Engineers, Inc. under the
direction of the undersigned professional engineer whose seal and signature appears hereon.
Todd R. Whipple, P.E.
TABLE OF CONTENTS
EXECUTIVE SUMMARY ........................................................................................................................................... 1
INTRODUCTION ........................................................................................................................................................ 4
Introduction, Purpose of Report and Study Area ........................................................................................... 4
Site Location and Development Description ................................................................................................. 4
EXISTING AND PROPOSED CONDITIONS ....................................................................................................... 15
Existing and Proposed Conditions within the Study Area ............................................................................ 15
Land Use & Zoning ...................................................................................................................................... 15
Existing Roadways ........................................................................................................................................ 15
Schafer Branch Road ............................................................................................15
Farr Road ..............................................................................................................15
44th Avenue ...........................................................................................................15
Woodruff Road ......................................................................................................15
Cimmaron Drive ....................................................................................................16
Schafer Road .........................................................................................................16
Bowdish Road .......................................................................................................16
Dishman-Mica Road .............................................................................................16
Study Area Intersections ............................................................................................................................... 16
Traffic Control and Descriptions .................................................................................................................. 17
44th Avenue & Schafer Branch Road ...................................................................17
Leonidas Lane & Schafer Branch Road (Proposed) ...........................................17
Ellie Bells Lane & Schafer Branch Road (Proposed) ..........................................17
44th Avenue & Ponderosa Lane ...........................................................................17
44th Avenue & Locust Road (Proposed) ..............................................................17
44th Avenue & Farr Road .....................................................................................17
45th Avenue & Farr Road .....................................................................................17
47th Avenue & Farr Road (Proposed) ..................................................................18
Cimmaron Drive & Woodruff Road .....................................................................18
44th Avenue & Woodruff Road ............................................................................18
Dishman-Mica Road & Schafer/University Road ................................................18
Cimmaron Drive & Schafer Road ........................................................................18
44th Avenue & Schafer Road ................................................................................18
Dishman-Mica Road & Bowdish Road ................................................................18
44th Avenue & Bowdish Road ..............................................................................18
Existing Intermodal Transportation System ................................................................................................. 19
Traffic Volumes and Peak Hours of Operation ........................................................................................... 20
Traffic Safety ................................................................................................................................................. 20
Public Involvement ....................................................................................................................................... 23
LEVEL OF SERVICE ............................................................................................................................................... 25
Signalized Intersections ................................................................................................................................. 25
Unsignalized Intersections ............................................................................................................................ 26
LEVEL OF SERVICE AND TRAFFIC ANALYSIS ............................................................................................... 27
Existing Level of Service and Traffic Analysis .............................................................................................. 27
BACKGROUND TRAFFIC GROWTH & BACKGROUND PROJECTS ............................................................. 30
Background Traffic Growth ......................................................................................................................... 30
Background Project Traffic .......................................................................................................................... 30
TRIP GENERATION AND DISTRIBUTION ......................................................................................................... 34
Trip Distribution Characteristics of the Proposed Project ............................................................................ 34
FUTURE YEAR TRAFFIC IMPACT ANALYSIS ................................................................................................... 39
Future Year Traffic Impact Analysis (Buildout) .......................................................................................... 39
Year 2030 without the Project ....................................................................................................................... 40
Year 2030 with Ponderosa Ridge County ..................................................................................................... 43
Year 2030 with Ponderosa Ridge County & Ponderosa Ridge City ............................................................. 46
Horizon Year Traffic Impact Analysis (Buildout + 5 Years) ...................................................................... 49
Year 2035 without the Project ....................................................................................................................... 50
Year 2035 with Ponderosa Ridge County ..................................................................................................... 53
Year 2035 with Ponderosa Ridge County & Ponderosa Ridge City ............................................................. 56
ADDITIONAL ANALYSIS – SIGHT DISTANCE STUDY .................................................................................... 56
CONCLUSIONS & RECOMMENDATIONS .......................................................................................................... 63
Conclusions................................................................................................................................................... 63
Recommendations ........................................................................................................................................ 63
LIST OF FIGURES
Figure 1 – Vicinity Map .................................................................................................................12
Figure 2-A – Ponderosa Ridge Phase II (County) Site Plan .........................................................13
Figure 2-B – Ponderosa Ridge (City) Site Plan ............................................................................13
Figure 3 – 2023 Existing AM Peak Hour Traffic Volumes ............................................................28
Figure 4 – 2023 Existing PM Peak Hour Traffic Volumes ............................................................29
Figure 5 – AM Background Trips ..................................................................................................32
Figure 6 – PM Background Trips ..................................................................................................33
Figure 7 – AM Ponderosa Ridge County Trip Distribution ..........................................................35
Figure 8 – PM Ponderosa Ridge County Trip Distribution ..........................................................36
Figure 9 – AM Ponderosa Ridge City Trip Distribution ...............................................................37
Figure 10 – PM Ponderosa Ridge City Trip Distribution .............................................................38
Figure 11 – 2030 AM Traffic Volumes without Project ................................................................41
Figure 12 – 2030 PM Traffic Volumes without Project ................................................................42
Figure 13 – 2030 AM Traffic Volumes with Ponderosa Ridge County .........................................44
Figure 14 – 2030 PM Traffic Volumes with Ponderosa Ridge County .........................................45
Figure 15 – 2030 AM Traffic Volumes with Ponderosa Ridge County & City .............................47
Figure 16 – 2030 PM Traffic Volumes with Ponderosa Ridge County & City .............................48
Figure 17 – 2035 AM Traffic Volumes without Project ................................................................51
Figure 18 – 2035 PM Traffic Volumes without Project ................................................................52
Figure 19 – 2035 AM Traffic Volumes with Ponderosa Ridge County .........................................54
Figure 20 – 2035 PM Traffic Volumes with Ponderosa Ridge County .........................................55
Figure 21 – 2035 AM Traffic Volumes with Ponderosa Ridge County & City .............................57
Figure 22 – 2035 PM Traffic Volumes with Ponderosa Ridge County & City .............................58
LIST OF TABLES
Table 1A – ADT Calculation – 24 hr intersection entering vehicle 10% ......................................21
Table 1B – Accident Data for Intersections within the Study Area ...............................................22
Table 2 – 2023 Existing Intersections Levels of Service (Figure 3&4) .........................................27
Table 3 – Summary of the Background Project Trip Generation (Figures 5&6) ..........................30
Table 4 – Trip Generation Rates for LUC # 210 – Single Family Detached Housing (Fig. 7-10)
............................................................................................................................................34
Table 5 – Year 2030 Level of Service, without the Project (Figures 11&12) ...............................40
Table 6 – Year 2030 Level of Service, with Ponderosa Ridge County (Figures 13&14) ..............43
Table 7 – Year 2030 Level of Service, with Ponderosa Ridge County & City (Figures 15&16) ..46
Table 8 – Year 2035 Level of Service, without the Project (Figures 17&18) ...............................50
Table 9 – Year 2035 Level of Service, with Ponderosa Ridge County (Figures 19&20) ..............53
Table 10 – Year 2035 Level of Service, with Ponderosa Ridge County & City (Figures 21&22) 56
TECHNICAL APPENDIX
Level of Service Methods, Criteria and Tables
Accident Data
Raw Traffic Counts
Background Projects
Level of Service Calculations for Existing Conditions
Level of Service Calculations for year 2030 without the Project, with the Background
Level of Service Calculations for year 2030 with Ponderosa Ridge County
Level of Service Calculations for year 2030 without Ponderosa Ridge County & City
Level of Service Calculations for year 2035 without the Project, with the Background
Level of Service Calculations for year 2035 with Ponderosa Ridge County
Level of Service Calculations for year 2035 with Ponderosa Ridge County & City
Whipple Consulting Engineers, Inc. 1 Ponderosa Ridge
EXECUTIVE SUMMARY
Supplemental to the SEPA Process for the proposed Ponderosa Ridge development, the
following Traffic Impact Analysis applies:
1. Spokane County, and the City of Spokane Valley, have established Level of Service D as
the minimum acceptable level for signalized intersections and Level of Service E for
unsignalized intersections.
2. The project proposes to develop approximately 33.41 +/- acres into 49 single family
residential lots for Ponderosa Ridge Phase II in Spokane County and 81 single family
residential lots for Ponderosa Ridge East in the City of Spokane Valley, total of 130 units
single family residential lots. The project site is currently undeveloped with field grass,
weeds, and trees.
3. A request has been made by the City of Spokane Valley to include within this traffic
analysis an evacuation plan for not only the proposed project but for the entirety of the
Ponderosa Neighborhood. Included within this report is a brief history of the events that
have occurred within and around the ponderosa neighborhood as well as links and
refences to the existing Spokane County All Hazards Evacuation Plan that is inclusive of
the Ponderosa neighborhood and is the guiding policy document of Spokane County Fire
District 8 for which the project is within.
4. Per the Resolution Number 21-07 (attached Page 6), the Board of Fire Commissioners of
Spokane County Fire District No. 8 recommends to the City of Spokane Valley Building
Department that no further development be allowed in the Ponderosa Neighborhood
within the incorporated boundary of the City of Spokane Valley, unless the following
requirements have been met:
Automatic residential sprinkler systems shall be installed in all new homes per the
International Residential Code (IRC)
A minimum of a 30-foot green space shall be constructed around the entire development
of new homes to buffer the threat of wildland fire; and
Buildings and structures shall be constructed in accordance with the Wildland-Urban
Interface Code Class 3 Ignition-Resistant construction.
The project will meet these standards and no further fire access evaluation is required.
5. Ponderosa Ridge Phase II (County)
It is anticipated that lots 1,6,7,8,9,10, &11 of Ponderosa Ridge Phase II (County) will
front and access Schafer Branch Road. Lots 23 through 49 of the county project are
located along Ponderosa Lane and 48th Avenue. The county portion of the project
proposes to extend Ponderosa Lane to 48th Avenue. Along the western boundary of
County project, the project proposes the development of two private roads off of Schafer
Branch Road which will provide access to the development. Ellie Belles Lane is proposed
to extend east and then turn north and terminate with a hammerhead. Leonidas Lane is
proposed to extend east and terminate with a cul-de-sac.
Whipple Consulting Engineers, Inc. 2 Ponderosa Ridge
6. Ponderosa Ridge East (City)
The city portion of the project proposes to build Locust Road south from 44th Avenue
through 48th Avenue. 45th Avenue is proposed to be extended east to Farr Road. 46th
Avenue is proposed to be extended east from Ponderosa Lane through Locust Road and
terminate with a cul-de-sac. The Ponderosa Ridge East (City) project has been previously
approved to extend 48th Avenue to Farr Road. The project also proposes to build 47th
Avenue west to Locust Road and continue as a Fire access to Ponderosa Lane. The
expected build out year is 2030. Please see Figures 2-A (County) & 2-B (City),
Preliminary Site Plan.
7. The site is currently zoned as Low Density Residential (LDR) for Ponderosa Ridge Phase
II in Spokane County and Single Family Residential (R-3) for Ponderosa Ridge East in
the City of Spokane Valley. The subject property is located in a portion of NW ¼ Section
05, T 24 N., R 44 E., W.M. The parcel numbers for the project are 44052.9230 and
44052.9011. The surrounding areas include residential and undeveloped land uses.
8. The project study area intersections were identified through conversations with the City of
Spokane Valley, Spokane County, and WSDOT. The study encompasses the AM and PM
peak hour analysis of the following intersections:
44th Avenue & Schafer Branch Road
Leonidas Lane & Schafer Branch Road (Proposed)
Ellie Bells Lane & Schafer Branch Road (Proposed)
44th Avenue & Ponderosa Lane
44th Avenue & Locust Road (Proposed)
44th Avenue & Farr Road
45th Avenue & Farr Road
47th Avenue & Farr Road (Proposed)
Cimmaron Drive & Woodruff Road
44th Avenue & Woodruff Road
Dishman-Mica Road & Schafer/University Road
Cimmaron Drive & Schafer Road
44th Avenue & Schafer Road
Dishman-Mica Road & Bowdish Road
44th Avenue & Bowdish Road
9. The proposed residential development is anticipated to generate 95 trips in the AM peak
hour with 25 trips entering the site and 70 trips exiting the site. In the PM peak hour, the
proposed residential development is anticipated to generate 128 trips with 81 trips entering
the site and 47 trips exiting the site. The land use of the development is anticipated to
generate 1,285 average daily trips to/from the project site.
10. Conclusions
This Traffic Impact Analysis (TIA) has reviewed and analyzed the study area per the project
scope established by Spokane County and the City of Spokane Valley with public scoping
Whipple Consulting Engineers, Inc. 3 Ponderosa Ridge
meeting. Based upon the analysis, field observations, assumptions, methodologies, and results
which are provided in the body of this report, it is concluded that the development of the
proposed projects will generate new trips on the existing transportation system and that those
trips, while affecting Level of Service (LOS), will not degrade the LOS below acceptable levels
for the buildout (2030) and the buildout + 5 years (2035). This conclusion was reached and has
been documented within the body of this report.
Under the existing conditions, all intersections are currently operating at an
acceptable level of service.
For the year 2030 with background without projects scenario, all intersections
are anticipated to continue to operate at an acceptable level of service.
For the year 2030 with background with Ponderosa Ridge County scenario, all
intersections are anticipated to continue to operate at an acceptable level of
service.
For the year 2030 with background with Ponderosa Ridge County &
Ponderosa Ridge City scenario, all intersections are anticipated to continue to
operate at an acceptable level of service.
For the year 2035 with background without projects scenario, all intersections
are anticipated to continue to operate at an acceptable level of service.
For the year 2035 with background with Ponderosa Ridge County scenario, all
intersections are anticipated to continue to operate at an acceptable level of
service.
For the year 2035 with background with Ponderosa Ridge County &
Ponderosa Ridge City scenario, all intersections are anticipated to continue to
operate at an acceptable level of service.
Additional Analysis – Sight Distance there is sufficient sight distance available
at all existing and proposed locations provided that the right-of-way is kept clear
from vegetation.
1. Recommendations
Based upon the conclusions within this study, the proposed projects are recommended to
complete all required conditions of approval and should be allowed to move forward
without further traffic analysis, or offsite mitigation.
Whipple Consulting Engineers, Inc. 4 Ponderosa Ridge
INTRODUCTION
Introduction, Purpose of Report and Study Area
This traffic impact analysis is required by Spokane County and the City of Spokane Valley as
part of the traffic concurrency and SEPA process for the proposed Ponderosa Ridge. The
proposed development consists of 130 Single Family Residential Lots on 33.41 acres +/- site.
Please see Figure 1 Vicinity Map and Figure 2 Preliminary Site Plan.
The purpose of this analysis is to review, assess, and identify the potential traffic related impacts
that the proposed project may have on the transportation network and where possible minimize
any impact. This TIA will be completed in accordance with the current traffic guidelines from
Spokane County, the City of Spokane Valley, Washington State Department of Transportation
(WSDOT), and the Institute of Transportation Engineers (A Recommended Practice – Traffic
Access and Impact Studies for Site Development, 2010) as well as their respective requirements.
Site Location and Development Description
The subject property is located on a portion of the NW ¼ Section 05, T 24 N., R 44 E., W.M.
within City of Spokane Valley and Spokane County, Washington. The project proposes to
develop 49 single family residential lots for Ponderosa Ridge Phase II in Spokane County and 81
units single family residential lots for Ponderosa Ridge East in the City of Spokane Valley,
totaling 130 single family residential lots. The project site is currently undeveloped with field
grass, weeds, and trees.
Ponderosa Ridge Phase II (County)
It is anticipated that lots 1,6,7,8,9,10, &11 of Ponderosa Ridge Phase II (County) will front and
access Schafer Branch Road. Lots 23 through 49 of the county project are located along
Ponderosa Lane and 48th Avenue. The county portion of the project proposes to extend
Ponderosa Lane to 48th Avenue. Along the western boundary of County project, the project
proposes the development of two private roads off of Schafer Branch Road which will provide
access to the development. Ellie Belles Lane is proposed to extend east and then turn north and
terminate with a hammerhead. Leonidas Lane is proposed to extend east and terminate with a
cul-de-sac.
Ponderosa Ridge East (City)
The city portion of the project proposes to build Locust Road south from 44th Avenue through
48th Avenue. 45th Avenue is proposed to be extended east to Farr Road. 46th Avenue is proposed
to be extended east from Ponderosa Lane through Locust Road and terminate with a cul-de-sac.
The Ponderosa Ridge East (City) project has been previously approved to extend 48th Avenue to
Farr Road. The project also proposes to build 47th Avenue west to Locust Road and continue as a
Fire access to Ponderosa Lane. The expected build out year is 2030. Please see Figures 2-A
(County) & 2-B (City), Preliminary Site Plan.
Whipple Consulting Engineers, Inc. 5 Ponderosa Ridge
Ponderosa Neighborhood Fire Access Study Response
With the project Notice of Application issued by the City of Spokane Valley, agency and public
comments were received. Within a letter from the City of Spokane Valley dated December 27,
2022, a request was made for an evacuation plan to address the public comments. The following
is our response:
Based upon our review of the request as well as the emergency plans and preparedness in
response to Homeland security issues we find that the City of Spokane Valley, Spokane County
and associated Fire agencies have, over the last several years, analyzed this situation and agreed
on appropriate evacuation policies. Therefore, we find that there is no need for an evacuation
“plan” as there already exists a detailed and comprehensive evacuation plan and policies
prepared by qualified individuals and approved by the City of Spokane Valley, April 2020.
Current Evacuation Plan(s)
Spokane County in Partnership with multiple cities within Spokane County, including the City of
Spokane Valley, Participated in the preparation of the Spokane County Emergency Management
- Comprehensive Emergency Management Plan (CEMP)
https://www.spokanecounty.org/DocumentCenter/View/40021/Spokane-County-CEMP-
March_2021 2014 Spokane County All-Hazards Evacuation Plan included here by reference link
https://www.spokanecounty.org/DocumentCenter/View/4774/Evacuation-Plan-Update-2014-
PDF and in the 2021 Spokane County Emergency Management, Comprehensive Emergency
Management Plan. (CEMP) included here by reference link
https://www.spokanecounty.org/DocumentCenter/View/40021/Spokane-County-CEMP-
March_2021
These documents, while still relevant have been updated with the 2020 Spokane County Hazard
Mitigation Plan Vol 1 & Vol 2. Included here by reference link.
https://www.spokanecounty.org/DocumentCenter/View/34414/Hazard-Mitigation-Plan-Update-
Volume-1?bidId=
https://www.spokanecounty.org/DocumentCenter/View/34415/Hazard-Mitigation-Plan-Update-
Volume-2?bidId=
While volume 1 provides a general understanding, the evaluation standards and the operational
knowledge for the county, volume 2 provides community specific information regarding
resources and risks. Including wildland interfaces and evacuations.
It is important to note that through all of these documents the most important consideration is
that the extent and means of emergency evacuation of a neighborhood like the Ponderosa rests in
the hands of the incident commander. A professional that is on the ground with situational
awareness. Who does not need to reference a report in a City land use file, to make a decision to
act, as that might delay decisions and imperil the public. Spokane County over the past decades
have created a network of resources and infrastructure that coordinates all emergency personnel.
Special teams have been formed for the evacuation of large farm animals SCOPE Livestock
Emergency Evacuation Team (SLEET) as well as pets, Humane Emergency Animal Rescue
Team (HEART). Emergency Services has a priority to evacuate individuals with special needs
(handicapped or other condition that would prevent them from self-evacuating) under a level 1
Whipple Consulting Engineers, Inc. 6 Ponderosa Ridge
order. This would be for known elderly care facilities and schools. Unknown individuals
reporting through 911 operators would be added to the list. Evacuation facilities within the
community have also been screened and prepared in advance. Additionally, as stated within
these emergency plans there is a continual community outreach that has occurred and continues
to occur to reduce the risks of natural disasters.
But the most important element of the current plan and policies that negates any prepared
evacuation plan within a traffic study is an established chain of command that would supersede
any analysis that a licensed traffic engineer might prepare. As any evacuation plan, as a part of a
traffic study, would have to assume a static condition over a period of time. Such as where did
the fire start as well as other elements such as: humidity, temperature, available fuels, access,
point of ignition, wind direction… …etc. These variables however are never static. Which is
why they have all been incorporated within the chain of command and assigned to the
professional(s) disciplined to consider the matter at the time of the emergency.
Current Access
The Ponderosa Neighborhood is currently accessed
via Schafer Road and Bowdish/Sands Roads, both
are listed as Urban major collectors on the city of
Spokane Valley Arterial Map. There is also an
emergency vehicle access located at 48th Avenue &
Sands Road (shown with a star). The emergency
access is for emergency vehicles stationed at the fire
district headquarters in Valleyford, as those vehicles
would support the Bates Road fire station within the
Ponderosa Neighborhood. The key to the locked
gates are at the headquarters and not at the fire
station within the neighborhood at 44th Avenue &
Bates Road.
The theoretical maximum urban saturation flow rate of a single lane of travel is 1,750 passenger
car equivalents per hour per lane (PCEPHPL) (TRB-HCM)1 this capacity is for ideal conditions
on a straight segment of roadway without any intersections.
This rate is dependent upon headway and speed. At an average speed of 20 MPH with a single
car headway, a conservative flow rate could be between 1400 to 2350 PCEPHPL, under
managed control. The flow rate under an actual evacuation is unknowable, given the multiple
variables.
1 Transportation Research Board - Highway Capacity Manual and WSDOT Syncro & Simulation Protocol
Whipple Consulting Engineers, Inc. 7 Ponderosa Ridge
A Historical Discussion (only)
The Ponderosa Neighborhood has experienced two major fire events and several small events
over the history of the neighborhood. The two significant events occurred in 1991 and in 2008.
Both events affected the neighborhood differently.
The October 16, 1991 event was documented by a National Fire Protection Association
(NFPA) report. https://www.spokanecounty.org/DocumentCenter/View/4657/Firestorm-
1991-Report-PDF. The report notes that October 16th was a day that not only affected the
Ponderosa Neighborhood, but 91 separate fires burned within Spokane, Stevens, Ferry,
Okanogan and Pend Orielle Counties. The combination of all of these events strained the
available resources on that day. With limited means of communication by today’s
standards. The Ponderosa Neighborhood was evacuated that Wednesday morning and
afternoon by notices through local news, local radio and by in person notice. Yet, it was
reported, that there was little evacuation guidance for residents as to where and when to
go after evacuation, Given the many reports of fire throughout the day conflicts and
confusion were reported, and varied in severity and the perception of impact.
Resources: Total area wide commitment
Fire Crews: Spread out on other fires before 11 AM the start of the ponderosa fire.
Communication: VHF Radio, districts and crews on separate channels, limited
coordination.
Weather: High winds, visibility from dust and smoke impairment.
Obstructions: Downed trees over roadways due to high winds, limited access area
Public Notice: Emergency Activation System, Local TV, Local Radio, Patrol Officers
neighbors.
The 2008 event did not appear to be documented by the NFPA, but there are several
reports and mostly warnings to homeowners to maintain a defensible wildland interface
areas. https://www.spokanevalleyfire.com/fire-life-safety/wildfire-awareness/
https://www.dnr.wa.gov/firewise The significant difference between the 1991 event and
the 2008 event was that in 2008 a shelter in place evacuation schedule was implemented
within the immediate fire area, So, not all of the Ponderosa Neighborhood was evacuated
as was the case in the 1991 Event. In 2008 It was reported that those homes south of 48th
Avenue maintained their shelter in place order, and remained in their homes. For the
Ponderosa Neighborhood the shelter in place, and prepare for evacuation order was
imposed when the winds shifted from the west-east to northwest – southeast direction.
Prior to the wind shift the Camelot subdivision (Dishman-Mica & 16th Avenue) was
under the order. Both Neighborhoods are about the same age, and have similar Fuels. The
notice was broadcast on local news stations and on local radio stations. Additionally, the
(new at that time) University High School was designated as an evacuation shelter, where
the evacuees were funneled, and information was provided. There was still congestion
reported along roadways, but in contrast the reports of time delay were far shorter than
the 1991 event, as area responders had better tools and resources to evaluate conditions
and direct the residents out of harms way.
Whipple Consulting Engineers, Inc. 8 Ponderosa Ridge
Resources: singular event
Fire Crews: mobilized from supporting areas.
Communication: advanced VHF Radio, coordinated effort from mobile command center
(Lutheran Church Schafer Rd).
Weather: High winds, limited visibility from smoke
Obstructions: limited access area
Public Notice: Emergency Activation System, Shelter in place, Local TV, Local Radio,
Patrol Officers
When comparing the two fires the difference is clear with the advancements of not only
communication technology but also in training. Today’s Cellular Push notification per a cell
tower position is an important public communication for only those in the immediate area. In
regard to planning and training, In 1990 there was only two papers written on the subject. And
the NFPA report 299 that was used as a basis for legislation and the NFPA 1600 Series Reports.
With the legislation came the funding for Spokane County to develop the Evacuation Plan. With
the experience of the 2008 event and practice of shelter in place local fire departments bolstered
their resolutions to enforce defensible space within the ponderosa Neighborhood.
Current Restrictions/ Conditions
Per the Resolution Number 21-07 (attached Page 6), the Board of Fire Commissioners of
Spokane County Fire District No. 8 recommends to the City of Spokane Valley Building
Department that no further development be allowed in the Ponderosa Neighborhood within the
incorporated boundary of the City of Spokane Valley, unless the following requirements have
been met:
Automatic residential sprinkler systems shall be installed in all new homes per the
International Residential Code (IRC)
A minimum of a 30-foot green space shall be constructed around the entire
development of new homes to buffer the threat of wildland fire; and
Buildings and structures shall be constructed in accordance with the Wildland-Urban
Interface Code Class 3 Ignition-Resistant construction.
The project will meet these standards and no further fire access evaluation is required. The full
document of the Resolution Number 21-07 is included in pages 6-10 and Public Involvement
section of Appendix.
Whipple Consulting Engineers, Inc. 9 Ponderosa Ridge
Whipple Consulting Engineers, Inc. 10 Ponderosa Ridge
Whipple Consulting Engineers, Inc. 11 Ponderosa Ridge
WCEDRAWN:
PROJ #:
APPROVED:
DATE:
WHIPPLE CONSULTING ENGINEERS
CIVIL AND TRANSPORTATION ENGINEERING
21 SOUTH PINES ROAD
SPOKANE VALLEY, WASHINGTON 99206
PH:509-893-2617 FAX: 509-926-0227VICINITY MAPFIGURE 1
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TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON
20-279801/26/23MTRTRW
WCEDRAWN:
PROJ #:
APPROVED:
DATE:
WHIPPLE CONSULTING ENGINEERS
CIVIL AND TRANSPORTATION ENGINEERING
21 SOUTH PINES ROAD
SPOKANE VALLEY, WASHINGTON 99206
PH:509-893-2617 FAX: 509-926-0227PRELIMINARY SITE PLANFIGURE 2-A
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TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE PHASE II(COUNTY)9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON
20-279801/26/23MTRTRW
WCEDRAWN:
PROJ #:
APPROVED:
DATE:
WHIPPLE CONSULTING ENGINEERS
CIVIL AND TRANSPORTATION ENGINEERING
21 SOUTH PINES ROAD
SPOKANE VALLEY, WASHINGTON 99206
PH:509-893-2617 FAX: 509-926-0227PRELIMINARY SITE PLANFIGURE 2-B
W E
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TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE EAST(PUD)(CITY)
CITY OF SPOKANE VALLEY, WASHINGTONCITY OF SPOKANE VALLEYSPOKANE COUNTY20-279801/26/23MTRTRW
Whipple Consulting Engineers, Inc. 15 Ponderosa Ridge
EXISTING AND PROPOSED CONDITIONS
Existing and Proposed Conditions within the Study Area
Land Use & Zoning
The Ponderosa Ridge Phase II is currently designated and zoned as Low Density Residential
(LDR) in Spokane County. The Ponderosa Ridge East is currently designated and zoned as
Single Family (R-3) in the City of Spokane Valley. The subject property is located in a portion of
NW ¼ Section 05, T 24 N., R 44 E., W.M. The parcel numbers for the project are 44052.9230
and 44052.9011. The surrounding areas include residential and undeveloped land uses.
Existing Roadways
The overall transportation network in this area consists of an urban principal arterial, minor
arterials, major collectors, and local access roads. The projects are proposed to be accessed by
two (2) accesses on Schafer Branch Road, two (2) accesses on 44th Avenue and two (2) accesses
on Farr Road. The proposed project trips are anticipated to use the following roadways:
Schafer Branch Road is a north/south, two-way, 2-lane, unpaved local access road that extends
south from 44th Avenue and ends at a private driveway. Schafer Branch Road serves residential
land uses. The speed limit on Schafer Branch Road is 25 MPH.
Farr Road within the study area is a north/south, two-way, 2-lane, local access road that extends
south from 44th Avenue through 45th and 46th Avenues to Holman Road. Farr Road serves
residential land uses. The speed limit on Farr Road is 25 MPH.
Locust Road within the study area is a north/south, two-way, 2-lane local access road that
extends north from 44th Avenue through 43rd Avenue another 150 feet before terminating. Locust
Road Serves residential land uses. The speed limit on Locust Road is 25 MPH.
44th Avenue is an east/west, two-way, 2-lane, urban major collector that extends east from a
private driveway through Schafer Branch Road, Woodruff Road, Schafer Road, Van Marter
Road, Bowdish Road, and Bates Road before transitioning into Sands Road. 44th Avenue serves
residential land uses. The speed limit on 44th Avenue is 35 MPH.
45th Avenue within the study area is an east west, two-way, 2 lane local access road that extends
west from Farr Road approximately 300 feet to the project boundary. 45th Avenue currently
serves residential land uses. The speed limit on 45th Avenue is 25 MPH.
Woodruff Road within the study area is generally a north/south, two-way, 2-lane, local access
road that extends south from 36th Avenue through 39th Avenue, Cimmaron Drive, Driftwood
Drive, 44th Avenue and 48th Avenue before terminating at Holman Road. Woodruff Road
serves generally residential and institutional land uses. The speed limit on Woodruff Road is 25
MPH. The speed limit near the Ponderosa Elementary School is 20 MPH when children are
present.
Whipple Consulting Engineers, Inc. 16 Ponderosa Ridge
Cimmaron Drive is generally an east/west, two-way, 2-lane, local access road that extends east
from Sunderland Drive through Woodruff Road, Driftwood Drive, Ridgeview Drive, Schafer
Road, and Conifer Court before terminating. Cimmaron Drive serves generally residential and
institutional land uses. The speed limit on Cimmaron Drive is 25 MPH. The speed limit on
Cimmaron Drive is 25 MPH. The speed limit near the Ponderosa Elementary School is 20 MPH
when children are present. The speed limit near the Ponderosa Elementary School is 20 MPH
when children are present.
Schafer Road is generally a north/south, two-way, 2-lane, urban major collector that extends
south from Dishman-Mica Road through Cinnamon Avenue before ending at 44th Avenue.
Schafer Road serves generally residential and institutional land uses. The speed limit on Schafer
Road is 35 MPH. The speed limit near the Cimmaron Drive is 20MPH when School Zone
Flashing Beacons are on.
Bowdish Road is generally a north/south, two-way, 2-lane, urban minor arterial/major collector
/local access road that starts as local access south of I-90 south to Mission Avenue. From
Mission Avenue, it becomes an urban minor arterial extends south through Broadway, Sprague,
4th, 8th, 16th, 24th, and 32nd Avenues before becoming an urban major collector at Dishman-
Mica Road and transitioning into Sands Road. At the intersection of Bowdish Road and Sands
Road, Bowdish Road as a local access road that goes through Sundown Drive before terminating
at 44th Avenue. Bowdish Road serves generally residential, commercial, and institutional land
uses. The speed limit on Bowdish Road is 35 MPH north of Sands Road and 25 MPH south of
Sands Road.
Dishman-Mica Road is generally a north/south, two-way, 2-3-4 & 5-lane principal arterial that
extends southeast from Appleway Boulevard through 8th Avenue, 16th Avenue, 32nd Avenue,
University Road, Bowdish Road and Mohawk Drive before sweeping east and terminating at an
intersection with State Route 27. Dishman-Mica Road serves generally commercial and
residential land uses. The posted speed limit on Dishman-Mica Road is 45 MPH in the study
area.
Study Area Intersections
The project study area intersections were identified through a public traffic scoping meeting and a
conversation with Spokane County and the City of Spokane Valley. The study includes the original
TIA Scope, intersections and project accesses and encompasses the AM and PM peak hour analysis
of the following intersections:
44th Avenue & Schafer Branch Road
Leonidas Lane & Schafer Branch Road (Proposed)
Ellie Bells Lane & Schafer Branch Road (Proposed)
44th Avenue & Ponderosa Lane
44th Avenue & Locust Road (Proposed)
44th Avenue & Farr Road
45th Avenue & Farr Road
47th Avenue & Farr Road (Proposed)
Cimmaron Drive & Woodruff Road
Whipple Consulting Engineers, Inc. 17 Ponderosa Ridge
44th Avenue & Woodruff Road
Dishman-Mica Road & Schafer/University Road
Cimmaron Drive & Schafer Road
44th Avenue & Schafer Road
Dishman-Mica Road & Bowdish Road
44th Avenue & Bowdish Road
Traffic Control and Descriptions
44th Avenue & Schafer Branch Road is an unsignalized stop-controlled “T”-type intersection
with stop control on Schafer Branch Road, with the following lane configuration: the eastbound
approach has one receiving lane and a through-right lane. The westbound approach has one
receiving lane and a left-through lane. The northbound approach has one receiving lane and a
left-right turn lane.
Leonidas Lane & Schafer Branch Road (Proposed) is an unsignalized stop-controlled “T”-
type intersection with stop control on Leonidas Lane, with the following lane configuration: the
westbound approach has one receiving lane and a left-right turn lane. The northbound approach
has one receiving lane and a through-right lane. The southbound approach has one receiving lane
and a left-through lane.
Ellie Bells Lane & Schafer Branch Road (Proposed) is an unsignalized stop-controlled “T”-
type intersection with stop control on Ellie Bells Lane, with the following lane configuration: the
westbound approach has one receiving lane and a left-right turn lane. The northbound approach
has one receiving lane and a through-right lane. The southbound approach has one receiving lane
and a left-through lane.
44th Avenue & Ponderosa Lane is an unsignalized stop-controlled “T”-type intersection with
stop control on Ponderosa Lane, with the following lane configuration: the eastbound approach
has one receiving lane and a through-right lane. The westbound approach has one receiving lane
and a left-through lane. The northbound approach has one receiving lane and a left-right turn
lane.
44th Avenue & Locust Road (Proposed) is an unsignalized stop-controlled intersection with
stop control on Locust Road, with the following lane configuration: All approaches will have one
receiving lane and a left-through-right lane.
44th Avenue & Farr Road is an unsignalized stop-controlled “T”-type intersection with stop
control on Farr Road, with the following lane configuration: the eastbound approach has one
receiving lane and a through-right lane. The westbound approach has one receiving lane and a
left-through lane. The northbound approach has one receiving lane and a left-right turn lane.
45th Avenue & Farr Road is an unsignalized stop-controlled “T”-type intersection with stop
control on 45th Avenue, with the following lane configuration: the eastbound approach has one
receiving lane and a left-right turn lane. The northbound approach has one receiving lane and a
left-through lane. The southbound approach has one receiving lane and a through-right lane.
Whipple Consulting Engineers, Inc. 18 Ponderosa Ridge
47th Avenue & Farr Road (Proposed) is an unsignalized stop-controlled “T”-type intersection
with stop control on 47th Avenue, with the following lane configuration: the eastbound approach
has one receiving lane and a left-right turn lane. The northbound approach has one receiving lane
and a left-through lane. The southbound approach has one receiving lane and a through-right
lane.
Cimmaron Drive & Woodruff Road is an unsignalized stop-controlled intersection with four-
way stop control, with the following lane configuration: All approaches have one receiving lane
and a left-through-right lane.
44th Avenue & Woodruff Road is an unsignalized stop-controlled intersection with stop control
on Woodruff Road, with the following lane configuration: All approaches have one receiving
lane and a left-through-right lane.
Dishman-Mica Road(E/W) & Schafer/University Road(N/S) is a signalized intersection with
the following lane configuration: the eastbound approach has two receiving lanes, a left turn
lane, a through lane and a right turn lane. The westbound approach has one receiving lane, a left
turn lane, a through lane, and a right turn slip lane. The northbound approach has one receiving
lane, a left turn lane, and a through-right lane. The southbound approach has two receiving lanes,
a left turn lane, a through lane, and a right turn lane.
Cimmaron Drive & Schafer Road is an unsignalized stop-controlled intersection with stop
control on Cimmaron Drive, with the following lane configuration: the all approaches have one
receiving lane and a left-through-right lane.
44th Avenue & Schafer Road is an unsignalized stop-controlled “T”-type intersection with
three-way stop control, with the following lane configuration: the eastbound approach has one
receiving lane and a left-through lane. The westbound approach has one receiving lane and a
through-right lane. The southbound approach has one receiving lane and a left-right turn lane.
Dishman-Mica Road(E/W) & Bowdish Road(N/S) is a signalized intersection with the
following lane configuration: The east and westbound approaches have one receiving lane, a left
turn lane, and a through-right lane. The northbound approach has one receiving lane and a left-
through-right lane. The southbound approach has one receiving lane, a left-through lane, and a
right turn lane.
44th Avenue & Bowdish Road is an unsignalized stop-controlled “T”-type intersection with stop
control on Bowdish Road and with the following lane configuration: the eastbound approach has
one receiving lane and a left-through lane. The westbound approach has one receiving lane and a
through-right lane. The southbound approach has one receiving lane and a left-right turn lane.
Whipple Consulting Engineers, Inc. 19 Ponderosa Ridge
Existing Intermodal Transportation System
The existing intermodal transportation system including student transportation system
(pedestrian sidewalks & school bus), bikeways, public transit(bus), and on-street parking in this
study area are described as follows.
Student Transportation System
The proposed project site is located within the Central Valley School District, and it is expected
that the Ponderosa Elementary School, Horizon Middle School, and University High School will
serve the site for school aged children. Bus service for all three schools is currently provided
within the project site. The bus stop for Ponderosa Elementary School is located at the
intersection of 44th Avenue & Farr Road (4416 Far Road). The bus stop for Horizon Middle
School and University High School is located at the intersection of 44th Avenue & Woodruff
Road. As the project site is within less than one mile distance from Ponderosa Elementary
School, it is anticipated that the students would either walk or take a school bus to/from the
school. Sidewalks are planned within the development and along the site’s frontage. Based upon
the Pedestrian Network Map from the City of Spokane Valley, either existing or proposed
sidewalks are placed on 44th Avenue from Ponderosa Lane to Woodruff Road and existing
sidewalks are placed on Woodruff Road from 44th Avenue to Cimmaron Drive and Ponderosa
Elementary School. Therefore, we are assuming that these sidewalks can adequately and safely
accommodate the children from the project site. A graphical summary of student transportation
system is shown below.
Source: The City of Spokane Valley & Central Valley School District
Bikeways
Whipple Consulting Engineers, Inc. 20 Ponderosa Ridge
Based upon the Bike Routes Map from the City of Spokane Valley, there are two main bike
routes within the study area as shown in the following exhibit. Route 1 starts east from Woodruff
Road along 44th Avenue to Schafer Road and continues north along Schafer Road to Dishman-
Mica Road. Route 2 starts east from Woodruff Road along 44th Avenue to Sands Road and
continues north along Schafer Road to Bowdish Road. The City of Spokane Valley proposes
bike lanes along Bowdish Road north from Sands Road and shared use bike lanes along Dishman
Mica Road from Thorpe Road to Schafer Road.
Source: The City of Spokane Valley
Public Transit (Bus)
Public Transit is not available within walking distance (≤ 1 mile) from the project site.
On-street Parking
On-street Parking is available along Farr Road surrounding the project site.
Traffic Volumes and Peak Hours of Operation
Traffic counts were initially collected in July of 2020 and replaced by counts in September 2022
and January 2023 per city comment, under the direction of Whipple Consulting Engineers (WCE),
at the following intersection:
44th Avenue & Schafer Branch Road
44th Avenue & Ponderosa Lane
44th Avenue & Locust Road
44th Avenue & Farr Road
Cimmaron Drive & Woodruff Road
44th Avenue & Woodruff Road
Dishman-Mica Road & Schafer/University Road
Cimmaron Drive & Schafer Road
44th Avenue & Schafer Road
Whipple Consulting Engineers, Inc. 21 Ponderosa Ridge
Dishman-Mica Road & Bowdish Road
44th Avenue & Bowdish Road
The AM & PM peak hours from these counts are shown on Figures 3 & 4. The raw data for these
counts are located in the technical appendix.
Traffic Safety
For the intersections within the study area accident report summaries were received from City of
Spokane Valley. Generally, accidents are documented by type of occurrence, such as property
damage or injury. No fatalities were reported for the study intersections during the last three
years.
ITE MEV Method
𝑅𝑎𝑡𝑒 𝑝𝑒𝑟 𝑀𝐸𝑉 ൌ 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑎𝑐𝑐𝑖𝑑𝑒𝑛𝑡𝑠 𝑖𝑛 𝑜𝑛𝑒 𝑦𝑒𝑎𝑟 𝑋 1 𝑚𝑖𝑙𝑙𝑖𝑜𝑛 𝑒𝑛𝑡𝑒𝑟𝑖𝑛𝑔 𝑣𝑒ℎ𝑖𝑐𝑙𝑒𝑠
24 ℎ𝑟 𝑖𝑛𝑡𝑒𝑟𝑠𝑒𝑐𝑡𝑖𝑜𝑛 𝑒𝑛𝑡𝑒𝑟𝑖𝑛𝑔 𝑣𝑒ℎ𝑖𝑐𝑙𝑒 𝑋 365 𝑋 1 𝑦𝑒𝑎𝑟𝑠
Equation 4-2 of ITE manual of traffic engineering studies (fourth edition)
Lacking specific 24 hr count data of the intersection, it is usual and customary to consider the
PM peak hour volume to represent 10% of the 24 hour volume (ADT- Average Daily Traffic)
see below
Table 1A – ADT Calculation – 24 hr intersection entering vehicle 10%
Intersection Peak
Hour
Volume
% of
Peak Hour
24 hr (ADT)
Volume
44th Avenue & Schafer Branch Road 16 10% 160
44th Avenue & Ponderosa Lane 53 10% 530
44th Avenue & Farr Road 72 10% 720
Cimmaron Drive & Woodruff Road 82 10% 820
44th Avenue & Woodruff Road 146 10% 1,460
Dishman-Mica Road & Schafer/University Road 1,163 10% 11,630
Cimmaron Drive & Schafer Road 339 10% 3,390
44th Avenue & Schafer Road 220 10% 2,200
Dishman-Mica Road & Bowdish Road 931 10% 9,310
44th Avenue & Bowdish Road 129 10% 1,290
In this analysis accidents are measured based on frequency per million entering vehicles (MEV).
This ratio is a function of the average daily traffic entering the intersection and the annual
frequency of accidents. This method of analysis is also considered as an “exposure” analysis.
This method of analysis is used to identify areas that need further review. A typical review
threshold for accidents at an intersection is 1.00 accidents per MEV. The accident data for the
intersections within the study area are shown in Table 1B.
Whipple Consulting Engineers, Inc. 22 Ponderosa Ridge
Table 1B – Accident Data for Intersections within the Study Area
Intersection
2020 2021 2022 Avg
MEV
Per yr. PDO INJ PDO INJ PDO INJ
44th Avenue & Schafer Branch Road 0 0 0 0 0 0
MEV @ 10% of Roadway ADT 0.00 0.00 0.00 0.00
44th Avenue & Ponderosa Lane 0 0 0 0 0 0
MEV @ 10% of Roadway ADT 0.00 0.00 0.00 0.00
44th Avenue & Farr Road 0 0 0 0 0 0
MEV @ 10% of Roadway ADT 0.00 0.00 0.00 0.00
Cimmaron Drive & Woodruff Road 0 0 0 0 0 0
MEV @ 10% of Roadway ADT 0.00 0.00 0.00 0.00
44th Avenue & Woodruff Road 0 0 0 0 0 0
MEV @ 10% of Roadway ADT 0.00 0.00 0.00 0.00
Dishman-Mica Road &
Schafer/University Road 0 0 0 0 0 1
MEV @ 10% of Roadway ADT 0.00 0.00 0.23 0.08
Cimmaron Drive & Schafer Road 0 0 0 0 0 0
MEV @ 10% of Roadway ADT 0.00 0.00 0.00 0.00
44th Avenue & Schafer Road 0 0 0 0 0 0
MEV @ 10% of Roadway ADT 0.00 0.00 0.00 0.00
Dishman-Mica Road &
Bowdish Road 0 1 0 0 0 1
MEV @ 10% of Roadway ADT 0.29 0.00 0.29 0.20
44th Avenue & Bowdish Road 0 0 0 0 0 0
MEV @ 10% of Roadway ADT 0.00 0.00 0.00 0.00
Based upon this analysis all ratios, do not meet or exceed the threshold for further review.
Whipple Consulting Engineers, Inc. 23 Ponderosa Ridge
Public Involvement
On March 13, 2020, a public traffic scoping meeting was held at Ponderosa Elementary School
at 6:05 pm. The meeting was proctored by Todd Whipple. The citizens within the area were in
attendance. The concerns and questions were bought up by the citizens and were addressed at the
meeting and are addressed as follows.
1. Have the counts already occurred?
Note: Traffic Counts were recollected in Sept. 2022 and January 2023.
The traffic counts were collected July 2020. As described in Traffic Counts Adjustment
Factor, for the effect of the Covid Pandemic and non-school season, 2020 traffic counts
were adjusted by multiplying the counts by the adjustment factor. The brief explanation is
included in Traffic Counts Adjustment Factor section and the calculation and analysis are
included in Traffic Adjustment Factor of the Appendix.
2. Will the study include traffic anticipated from these new projects as well as existing
traffic?
The study will include existing traffic, traffic from projects which have vested before this
project and anticipated traffic from these projects.
3. Concern about fire and evacuation, the third access for fire evacuation is always locked
and not an appropriate third access, is it possible to do a study on emergency evacuation
of the area? This adds a lot of homes when you’re thinking of fire evacuation.
Per the Resolution Number 21-07 (attached Page 6), the Board of Fire Commissioners of
Spokane County Fire District No. 8 recommends to the City of Spokane Valley Building
Department that no further development be allowed in the Ponderosa Neighborhood
within the incorporated boundary of the City of Spokane Valley, unless the following
requirements have been met:
Automatic residential sprinkler systems shall be installed in all new homes per the
International Residential Code (IRC)
A minimum of a 30-foot green space shall be constructed around the entire
development of new homes to buffer the threat of wildland fire; and
Buildings and structures shall be constructed in accordance with the Wildland-Urban
Interface Code Class 3 Ignition-Resistant construction.
The project will meet these standards and no further fire access evaluation is required.
The full document of the Resolution Number 21-07 is included in Public Involvement
section of Appendix.
4. Speed concerns on 44th and Schafer, Can you considered adding stop signs on Schafer
Road? (Consideration about a need for traffic calming measures on Schafer Road)
Whipple Consulting Engineers, Inc. 24 Ponderosa Ridge
This comment was noted and forwarded to the agencies. Based upon the accident data
from the City of Spokane Valley, 5 of accidents within the study area for last 5 years
(2015-2019) were related to exceeding reasonable safe speed with snow or ice on the
road surface. Note: Crash data has been updated by the City of Spokane Valley. (Table 1)
5. It is not safe for our children to walk to school here. The asphalt path often has ice and
snow on it, and there is no path in some areas. There are many children walking to
school, and it affects the traffic in the area, does the traffic study include pedestrian
traffic on 44th Avenue?, there is a lack of sidewalk on 44th Avenue, as well as a lack of
maintenance.
Pedestrian sidewalks facilities and student transportation system were discussed in
Existing Intermodal Transportation System. Sidewalks are planned within the
development and along the site’s frontage. Based upon the Pedestrian Network Map from
the City of Spokane Valley, either existing or proposed sidewalks are placed on 44th
Avenue, Schafer Road, Woodruff Road, Cimmaron Drive, and Sands Road within the
study area. Based upon the accident data from the City of Spokane Valley, no pedestrian
accident was reported for last 5 years (2015-2019). With completion of the city proposed
pedestrian sidewalls within the study area, it is anticipated that the pedestrian safety is
improved. Note: Crash data has been updated by the City of Spokane Valley. (Table 1)
6. This subdivision does not fit in the area and will stress infrastructure, what is the potential
outcome from this traffic study?, a concern about TIA study based upon ITE Trip
Generation Manual.
The process and methodology about TIA study have been addressed in the meeting and
the outcome of the study is included in this document.
7. When would we see construction of these projects?
The earliest construction would be sometime in 2021.
8. There are trailheads in the area that result in a decent amount of traffic on the weekends.
This comment was noted and forwarded to the agencies.
9. The grade on Schafer Branch Road can be quite dangerous.
This comment was noted and forwarded to the agencies.
10. Will these new roads be public or private?
We don’t know at this time.
The memo for the public traffic meeting on March 13, 2020, is included in Public Involvement
section of Appendix.
Whipple Consulting Engineers, Inc. 25 Ponderosa Ridge
LEVEL OF SERVICE
Level of Service (LOS) is an empirical premise developed by the transportation profession to
quantify driver perception for such elements as travel time, number of stops, total amount of
stopped delay, and impediments caused by other vehicles afforded to drivers who utilize the
transportation network. It has been defined by the Transportation Research Board in the Highway
Capacity Manual 6th Edition. This document has quantified level of service into a range from
“A” which indicates little, if any, vehicle delay, to “F” which indicates significant vehicle delay
and traffic congestion that may lead to system breakdown due to volumes that may exceed
capacity.
Signalized Intersections
For signalized intersections, research has determined that average stopped delay per vehicle is
the best available measure of Level of Service. The following tables identify the relationships
between level of service and average stopped delay per vehicle. Spokane County and the City of
Spokane Valley (Level of Service Table 4.3 of the City of Spokane Valley Comprehensive Plan)
have adopted level of service D as the minimum acceptable level for all signalized intersections.
Level of Service Criteria and Descriptions - Signalized
LOS Delay Range
(sec) General Description
A 10
Very low delay at intersection.
All signal cycles clear.
No vehicles wait through more than one signal cycle.
B 10 to 20
Operating speeds beginning to be affected by other traffic.
Short traffic delays at intersections.
Higher average intersections delays resulting from more vehicles stopping.
C 20 to 35
Operating speeds and maneuverability closely controlled by other traffic.
Higher delays at intersections than for LOS B due to a significant number of vehicles stopping.
Not all signal cycles clear the waiting vehicles.
D 35 to 55
Tolerable operating speeds, but long traffic delays occur at intersections
The influence of congestion is noticeable.
Many vehicles stop and the proportion of vehicles not stopping declines.
The number of signal cycle failures, for which vehicles must wait through more than one signal
cycle are noticeable.
E 55 to 80
Speeds are restricted, very long traffic delays are experienced and traffic volumes are near
capacity.
Traffic flow is unstable, any interruption, no matter how minor, will cause queues to form and
service to deteriorate.
Traffic signal cycle failures are frequent occurrences.
F 80
Extreme delays resulting in long queues which may interfere with other traffic movements
Stoppages of long duration and speeds may drop to zero.
Vehicle arrival rates are greater than capacity.
Considered unacceptable by most drivers.
Whipple Consulting Engineers, Inc. 26 Ponderosa Ridge
Unsignalized Intersections
The calculation of Level of Service (LOS) at an unsignalized one/two-way stop-controlled
intersection is examined in the Transportation Research Board’s Highway Capacity Manual 6th
Edition. For unsignalized intersections, Level of Service is based on the delay experienced by
each movement and approach within the intersection. The concept of delay as presented for
unsignalized intersections in the Highway Capacity Manual is based on the amount of time a
vehicle must spend at the intersection. Vehicles passing straight through the intersection on the
major (uncontrolled) street experience no delay at the intersection. On the other hand, vehicles
which are turning left from the minor street, because they must yield the right of way to all right
turning vehicles, all left turning vehicles from the major street and all through vehicles on both
the minor and major streets, must spend more time at the intersection. Levels of Service are
assigned to individual movements within the intersection and are based upon the delay
experienced by each movement or approach.
The Transportation Research Board has determined what Levels of Service for unsignalized
intersections should be, by designating Level of Service A through F, where Level of Service A
represents a facility where no vehicle in any movement is delayed very long and Level of Service
F which represents a facility where there is excessive delay for the average vehicle in at least one
movement in the intersection. Spokane County and the City of Spokane Valley (Level of Service
Table 4.3 of the City of Spokane Valley Comprehensive Plan) have adopted level of service E
for all unsignalized intersections within the study area and LOS F is acceptable if the peak hour
traffic signal warrant is not met.
Level of Service Criteria and Descriptions - Unsignalized
LOS Delay Range
(sec)
Expected Delay to Minor
Street Traffic General Description
A 10 Little to No Delay Nearly all drivers find freedom of operation.
Very seldom is there more than one vehicle in the queue.
B 10 to 15 Short Traffic Delays Some drivers begin to consider the delay an inconvenience
Occasionally there is more than one vehicle in the queue.
C 15 to 25 Average Traffic Delays Many times, there is more than one vehicle in the queue.
Most drivers feel restricted, but not objectionably so.
D 25 to 35 Long Traffic Delays Often there is more than one vehicle in the queue.
Drivers feel quite restricted.
E 35 to 50 Very Long Traffic
Delays
Represents conditions in which, demand is near or equal capacity.
There is almost always more than one vehicle in the queue.
Drivers find the delays approaching intolerable levels.
F 50
Stop-and-Go Condition
Delays Generally
Longer than Acceptable
Forced flow.
Represents an intersection failure condition that is caused by geometric
and/or operational constraints external to the intersection
All Level of Service analyses described in this report were performed in accordance with the
procedures described above. As a final note, the Highway Capacity Manual (HCM) analysis and
procedures are based upon worst case conditions. Therefore, most of each weekday and the
weekends will experience traffic conditions better than those described within this document,
which are only for the peak hours of operation
Whipple Consulting Engineers, Inc. 27 Ponderosa Ridge
LEVEL OF SERVICE AND TRAFFIC ANALYSIS
Existing Level of Service and Traffic Analysis
The existing Levels of Service at the scoped intersections were calculated using the methods from
the 6th Edition Highway Capacity Manual as implemented in Synchro, version 11 - Build 122. The
existing Levels of Service for the intersection within the study area are summarized in Table 3.
The existing traffic volumes used for this report are shown on Figures 3&4.
Table 2 – 2023 Existing Intersections Levels of Service (Figure 3&4)
INTERSECTION
(S)ignalized
(U)nsignalized
AM Peak Hour PM Peak Hour
Delay
(sec) LOS Delay
(sec) LOS
44th Avenue & Schafer Branch Road U 8.4 A 8.4 A
44th Avenue & Ponderosa Lane U 8.4 A 8.4 A
44th Avenue & Locust Road U 8.9 A 8.7 A
44th Avenue & Farr Road U 8.6 A 8.5 A
45th Avenue & Farr Road U 8.6 A 8.6 A
Cimmaron Drive & Woodruff Road U 8.0 A 7.1 A
44th Avenue & Woodruff Road U 9.8 A 9.6 A
Dishman-Mica Road & Schafer/University Road S 15.5 B 16.4 B
Cimmaron Drive & Schafer Road U 10.7 B 11.1 B
44th Avenue & Schafer Road U 7.4 A 7.6 A
Dishman-Mica Road & Bowdish Road S 12.4 B 11.9 B
44th Avenue & Bowdish Road U 8.6 A 8.7 A
Spokane County and the City of Spokane Valley have adopted level of service D as the
minimum acceptable level for signalized intersections and level of service E as the minimum
acceptable level for unsignalized intersections.
As shown in Table 3, the intersections are currently operating at an acceptable level of service.
Intersection Queue Left and Right turn lanes
A review of the calculated queue lengths provided in the appendix under LOS calculations,
identified no deficiencies within the queue storage of the turn lanes.
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
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9100 EAST 44TH AVENUE
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APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-022742023 PM EXISTING VOLUME & LOS VOLUMES = RAW COUNTSAAAAAAABBBTRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTONWESNCALEGEND 20-279801/26/23MTRTRWAA
Whipple Consulting Engineers, Inc. 30 Ponderosa Ridge
BACKGROUND TRAFFIC GROWTH & BACKGROUND PROJECTS
Background Traffic Growth
Background traffic growth is an anticipated increase in traffic volume from year to year. As the
existing land uses that surround a transportation facility mature, an increase in traffic results and
may be due to either an increase in drivers per household or a household’s purchase of an
additional vehicle. Many things can cause an increase in the traffic volumes of a facility. The
objective of the background traffic growth rate is to anticipate what the traffic volumes may be in
the future. The background traffic growth rate for an area or street is determined by means of
physical counts collected by local governmental agencies. The counts are compared on a yearly
basis and a rate of increase is calculated from the data.
Based upon the recommended standard rate by agencies, the background growth rate was
determined to be 1.0% per year. Based on a ten-year build out, and a fifteen-year Horizon Year,
compounded annually, the total increase in traffic rate for the year 2030 and 2035 are anticipated
to be 1.105 and 1.161.
Background Project Traffic
In addition to the natural increase in background growth, background projects that have already
been approved or have made application and have been vested before this project have been
included. The summary of background project traffic volumes used for this report are shown in
Table 4. Please see Figures 5 & 6 for a graphical representation of this distribution.
Table 3 – Summary of the Background Project Trip Generation (Figures 5&6)
Background Projects
AM Peak Hour Trips PM Peak Hour Trips
Vol. /
LUC
Directional
Distribution Vol. /
LUC
Directional
Distribution
In Out In Out
Painted Hills PRD (All) 380 95 285 545 338 207
Ponderosa East 2nd Addition (17 Lots) 17 4 13 19 12 7
Ponderosa Village (Partially Built) 135 69 66 62 39 23
Skyline Apartments (Duplex/Multi-
family) 22 6 16 23 14 9
Dishman Estates (29 lots) 26 6 20 31 20 11
Total 580 180 400 680 423 257
Painted Hills PRD: The project development is located northeast of Dishman Mica Road &
Thorpe Road on approximately 99.7 acres +/-. The site is proposed to be separated into six (6)
different land uses: 52 Cottages Style Single Family lots (Townhouses), 206 Single Family
Residential lots, 42 Estate Type Single Family (Large Lot Single Family Residential) lots, 228-
unit Multi-Family Residential, 4.26-acre Commercial development, and 52 Apartment units.
Ponderosa East 2nd Addition: The proposed residential subdivision is located east of Schafer
Road at the end of South Sundown Drive. The project development is proposed to develop
approximately 7.31± acres into a 22-lot residential subdivision.
Whipple Consulting Engineers, Inc. 31 Ponderosa Ridge
Ponderosa Village: The proposed development is located on the north side of Dishman-Mica
Road west of Bowdish Road. The development is proposed to develop 6.16 acres into a 5.736 ksf
High-Turnover Restaurant, a 16.695 ksf Specialty Retail Center, a 3.4 ksf Fast-Food Restaurant
with Drive-Through Window, and a 5.1 ksf Drinking Place.
Skyline Apartments: The project development is located northeast of Dishman-Mica Road near
40th Avenue. The project proposes to develop 1.18 acres +/- into a 32-unit multifamily residential
complex and 1.43 acres +/- into 6 duplex units and one single family unit.
Dishman Estates: The project development is located east of Dishman Mica Road on
approximately 20.64 acres +/-. The site is proposed to develop 7.23 +/- acres of 20.64 acres into
a 29-lot residential subdivision.
As shown in Table 4, the background projects are anticipated to total 580 trips in the AM Peak
Hour, with 180 trips entering and 400 trips exiting the various sites. In the PM Peak Hour, the
background projects anticipated to total 680 trips, with 423 trips entering and 257 trips exiting
the various sites.
WCEDRAWN:
PROJ #:
APPROVED:
DATE:
WHIPPLE CONSULTING ENGINEERS
CIVIL AND TRANSPORTATION ENGINEERING
21 SOUTH PINES ROAD
SPOKANE VALLEY, WASHINGTON 99206
PH:509-893-2617 FAX: 509-926-0227AM BACKGROUND TRIPSFIGURE 5
VOLUMES = BACKGROUND PROJECT STUDIES
WESNCLEGEND
00
242
TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON
20-279801/26/23MTRTRW
4
3
3
3
10
324
WCEDRAWN:APPROVED:
DATE:
WHIPPLE CONSULTING ENGINEERS
CIVIL AND TRANSPORTATION ENGINEERING
21 SOUTH PINES ROAD
SPOKANE VALLEY, WASHINGTON 99206
PH:509-893-2617 FAX: 509-926-0227PM BACKGROUND TRIPSFIGURE 6
VOLUMES = BACKGROUND PROJECT STUDIES
WESNCLEGEND
00
TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON
20-279801/26/23MTRTRW
PROJ #:
3
3
2
2
5
340
395
Whipple Consulting Engineers, Inc. 34 Ponderosa Ridge
TRIP GENERATION AND DISTRIBUTION
As noted earlier, trip generation rates for the AM and PM peak hours are determined by the use
of the Trip Generation Manual, 11th Edition published by the Institute of Transportation
Engineers (ITE). The purpose of the Trip Generation Manual is to compile and quantify
empirical data into trip generation rates for specific land uses within the US, UK, and Canada.
For the proposed 130 lot development (Ponderosa Ridge County: 49 lots, Ponderosa Ridge East
City: 81 lots), Land Use Code (LUC) # 210 Single-Family Detached Housing was used to
establish the number of potential trips generated by the land use. Per section 4.4 of the Trip
Generation Handbook 3rd Edition by ITE, the fitted curve equations were used to calculate new
project trips. The fitted curve equations and the anticipated number of AM and PM peak hour
trips for the land use of the proposed project are shown in Table 5.
Table 4 – Trip Generation Rates for LUC # 210 – Single Family Detached Housing (Fig. 7-10)
Project-
Dwelling Units
(% of Each Project)
AM Peak Hour Trips PM Peak Hour Trips
Fitted Curve
Equation
Directional
Distribution Fitted Curve
Equation
Directional
Distribution
26% In 74% Out 63% In 37% Out
County: 49 (37.1%) 36 9 27 48 30 18
City: 81 (62.9%) 59 16 43 80 51 29
Total: 130 (100.0 %) 95 25 70 128 81 47
Average Daily Trip Ends (ADT) Fitted Curve Equation
AM - Ln(T) = 0.91 Ln(x) + 0.12
PM - Ln(T) = 0.94 Ln(x) + 0.27
ADT - Ln(T) = 0.92 Ln(x) + 2.68
T = Trips/units, x = Dwelling Units
Project-Units (%) Fitted Curve
Equation ADT
County: 49 (37.1%) - 477
City: 81 (62.9%) - 808
Total: 130 (100.0 %) - 1,285
As shown in Table 5, the proposed residential developments are anticipated to generate 95 trips
in the AM peak hour with 25 trips entering the site and 70 trips exiting the site. In the PM peak
hour, the proposed residential developments are anticipated to generate 128 trips, with 81 trips
entering the site and 47 trips exiting the site. The land use of the developments is anticipated to
generate 1,285 average daily trips to/from the project over a 24-hour period.
Trip Distribution Characteristics of the Proposed Project
Considering many factors such as the surrounding transportation facilities, typical commuting
patterns, existing development in the area, and Average Daily Traffic counts, traffic for the
proposed development is anticipated as follows: 75% of trips are anticipated to go to/from the
north, west, and east of the site via Shafer Road. 25% of trips are anticipated to go to/from the
north, west, and east of the site via Bowdish Road. Of 75% of trips traveling via Schafer Road,
10% of the trips are anticipated to utilize Woodruff Road and Cimmaron Drive to drop the
children off at Ponderosa Elementary School in AM peak hour while all 75% of trips are
anticipated to utilize Schafer Road and 44th Avenue in PM peak hour. Please see Figures 7, 8, 9,
& 10 to see a graphical representation of this distribution.
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-0227AM COUNTY PROJECT TRIP DISTRIBUTION
TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON7 VOLUMES = TRIP GENERATION TABLETRIP GENERATIONTOTALINOUTAM PEAK36927LEGEND00WESNC1736179363633127363391120-279801/26/23MTRTRW
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-0227PM COUNTY PROJECT TRIP DISTRIBUTION8 VOLUMES = TRIP GENERATION TABLETRIP GENERATIONTOTALINOUTPM PEAK483018LEGEND00WESNC224922114949423749491214TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON
20-279801/26/23MTRTRW
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-0227AM CITY PROJECT TRIP DISTRIBUTION VOLUMES = TRIP GENERATION TABLETRIP GENERATIONTOTALINOUTAM PEAK591643LEGEND00WESNC346155346615627151518TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON9 20-279801/26/23MTRTRW
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-0227PM CITY PROJECT TRIP DISTRIBUTION VOLUMES = TRIP GENERATION TABLETRIP GENERATIONTOTALINOUTPM PEAK805129LEGEND00WESNC46827162828236192025TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON10 20-279801/26/23MTRTRW
Whipple Consulting Engineers, Inc. 39 Ponderosa Ridge
FUTURE YEAR TRAFFIC IMPACT ANALYSIS
Future Year Traffic Impact Analysis (Buildout)
Level of Service calculations for the Year 2030 conditions assumed that the existing traffic
volumes as shown on Figures 3 & 4 experience an increase above the existing volumes at the
established background rate. Three scenarios were examined for the year 2030 analysis. The first
scenario assumes that the development has not moved forward and analyzes the scoped
intersections with the background growth rate and the background project trips as shown on
Figures 5 & 6.
The second scenario assumes that the Ponderosa Ridge County project has moved forward and
analyzes the scoped intersections with the background growth rate, the background projects, and
the Ponderosa Ridge County project trips as shown on Figures 7 & 8.
The third scenario assumes that the Ponderosa Ridge City project has moved forward and
analyzes the scoped intersections with the background growth rate, the background projects, the
Ponderosa Ridge County as background and the Ponderosa Ridge City project trips as shown on
Figures 9 & 10. These scenarios will allow a determination to be made as to what the future
conditions may be both with and without the two projects.
Whipple Consulting Engineers, Inc. 40 Ponderosa Ridge
Year 2030 without the Project W/ Background and Growth
This scenario assumes that the developments have not moved forward. The traffic volumes for
this condition include the existing traffic, as shown on Figures 3 & 4, multiplied by the
background growth rate, plus the traffic from the background projects as shown on Figures 5 &
6. Please see Figures 11 & 12 for the traffic volumes used for this scenario. A summary of the
Level of Service results are shown in Table 6. This scenario creates a future year baseline that
allows for a direct comparison of the with project scenario.
Table 5 – Year 2030 Level of Service, without the Project W/ Background and Growth
INTERSECTION
(S)ignalized
(U)nsignalized
AM Peak Hour PM Peak Hour
Delay
(sec) LOS Delay
(sec) LOS
44th Avenue & Schafer Branch Road U 8.4 A 8.4 A
44th Avenue & Ponderosa Lane U 8.5 A 8.4 A
44th Avenue & Locust U 8.9 A 8.7 A
44th Avenue & Farr Road U 8.8 A 8.6 A
45th Avenue & Farr Road U 8.6 A 8.6 A
Cimmaron Drive & Woodruff Road U 8.1 A 7.1 A
44th Avenue & Woodruff Road U 9.9 A 9.7 A
Dishman-Mica Road & Schafer/University Road S 16.3 B 19.3 B
Cimmaron Drive & Schafer Road U 10.9 B 11.4 B
44th Avenue & Schafer Road U 7.5 A 7.7 A
Dishman-Mica Road & Bowdish Road S 15.7 B 14.6 B
44th Avenue & Bowdish Road U 8.6 A 8.8 A
Spokane County and the City of Spokane Valley have adopted level of service D as the
minimum acceptable level for signalized intersections and level of service E as the minimum
acceptable level for unsignalized intersections. As shown in Table 6, the intersections are
anticipated to operate at an acceptable level of service.
Intersection Queue Left and Right turn lanes
A review of the calculated queue lengths provided in the appendix under LOS calculations,
identified no deficiencies within the queue storage of the turn lanes.
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-02272030 AM VOLUME WITHOUT PROJECT & LOS VOLUMES = FIGURE 3 * BACKGROUND GROWTHAAAAAAABBTRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTONWESNCALEGEND11 20-279801/26/23MTRTRWAA BB
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-0227122030 PM VOLUME WITHOUT PROJECT & LOS VOLUMES = FIGURE 4 * BACKGROUND GROWTHAAAAAAABBBTRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTONWESNCALEGEND 20-279801/26/23MTRTRWAA
Whipple Consulting Engineers, Inc. 43 Ponderosa Ridge
Year 2030 with Ponderosa Ridge County W/ Background and Growth
This scenario assumes that the Ponderosa Ridge County project has moved forward and is added
to the previously established baseline. The traffic volume for this condition includes the traffic
volumes shown on Figures 11 & 12 and adds the Ponderosa Ridge County project trips as shown
on Figures 7 & 8. Please see Figures 13 & 14 for the traffic volumes used for this scenario. A
summary of the Level of Service results are shown in Table 7.
Table 6 – Year 2030 Level of Service, with Ponderosa Ridge County W/ Background &
Growth (Figures 13&14)
INTERSECTION
(S)ignalized
(U)nsignalized
AM Peak Hour PM Peak Hour
Delay
(sec) LOS Delay
(sec) LOS
44th Avenue & Schafer Branch Road U 8.4 A 8.4 A
Leonidas Lane (Access) & Schafer Branch Road U 8.4 A 8.3 A
Ellie Belle Bells Lane (Access) & Schafer Branch Road U 8.3 A 8.3 A
44th Avenue & Ponderosa Lane U 8.6 A 8.4 A
44th Avenue & Locust Road U 9.3 A 9.1 A
44th Avenue & Farr Road U 9.0 A 8.6 A
45th Avenue & Farr Road U 8.6 A 8.6 A
Cimmaron Drive & Woodruff Road U 8.1 A 7.1 A
44th Avenue & Woodruff Road U 10.3 B 10.1 B
Dishman-Mica Road & Schafer/University Road S 16.6 B 19.8 B
Cimmaron Drive & Schafer Road U 11.2 B 11.8 B
44th Avenue & Schafer Road U 8.0 A 7.9 A
Dishman-Mica Road & Bowdish Road S 15.9 B 15.0 B
44th Avenue & Bowdish Road U 8.6 A 8.8 A
Spokane County and the City of Spokane Valley have adopted level of service D as the
minimum acceptable level for signalized intersections and level of service E as the minimum
acceptable level for unsignalized intersections.
As shown in Table 7, the intersections are anticipated to operate at an acceptable level of service.
Intersection Queue Left and Right turn lanes
A review of the calculated queue lengths provided in the appendix under LOS calculations,
identified no deficiencies within the queue storage of the turn lanes.
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-02272030 AM VOLUME WITH COUNTY PROJECT & LOS VOLUMES = FIGURE 11 + FIGURE 7AAAAAABAABBBTRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTONWESNCALEGEND13 20-279801/26/23MTRTRWAA
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-0227142030 PM VOLUME WITH COUNTY PROJECT & LOS VOLUMES = FIGURE 12 + FIGURE 8AAAAAABAABBBTRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTONWESNCALEGEND 20-279801/26/23MTRTRWAA
Whipple Consulting Engineers, Inc. 46 Ponderosa Ridge
Year 2030 with Ponderosa Ridge County & Ponderosa Ridge City W/ Background and Growth
This scenario assumes that Ponderosa Ridge County & Ponderosa Ridge City have both moved
forward and are added to the previously established baseline. The traffic volumes for this
condition includes the traffic volumes shown on Figures 13 & 14 and adds the Ponderosa Ridge
City project trips as shown on Figures 9 & 10. Please see Figures 15 & 16 for the traffic volumes
used for this scenario. A summary of the Level of Service results is shown in Table 8.
Table 7 – Year 2030 Level of Service, with Ponderosa Ridge County & City W/ Background &
Growth (Figures 15&16)
INTERSECTION
(S)ignalized
(U)nsignalized
AM Peak Hour PM Peak Hour
Delay
(sec) LOS Delay
(sec) LOS
44th Avenue & Schafer Branch Road U 8.4 A 8.4 A
Leonidas Lane (Access) & Schafer Branch Road U 8.4 A 8.3 A
Ellie Belle Bells Lane (Access) & Schafer Branch Road U 8.3 A 8.3 A
44th Avenue & Ponderosa Lane U 8.6 A 8.4 A
44th Avenue & Locust Road (Access) U 9.5 A 9.6 A
44th Avenue & Farr Road U 9.5 A 8.7 A
45th Avenue (Access) & Farr Road U 8.7 A 8.7 A
47th Avenue (Access) & Farr Road U 8.6 A 8.6 A
Cimmaron Drive & Woodruff Road U 8.1 A 7.1 A
44th Avenue & Woodruff Road U 11.1 B 10.9 B
Dishman-Mica Road & Schafer/University Road S 17.0 B 21.1 C
Cimmaron Drive & Schafer Road U 11.8 B 12.7 B
44th Avenue & Schafer Road U 8.0 A 8.3 A
Dishman-Mica Road & Bowdish Road S 16.2 B 15.5 B
44th Avenue & Bowdish Road U 8.7 A 8.9 A
Spokane County and the City of Spokane Valley have adopted level of service D as the
minimum acceptable level for signalized intersections and level of service E as the minimum
acceptable level for unsignalized intersections.
As shown in Table 8, the intersections are anticipated to operate at an acceptable level of service.
Intersection Queue Left and Right turn lanes
A review of the calculated queue lengths provided in the appendix under LOS calculations,
identified no deficiencies within the queue storage of the turn lanes.
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-02272030 AM VOL. WITH COUNTY & CITY PROJECT & LOS15 AAAAAAABAAAABBBVOLUMES = FIGURE 15 + FIGURE 9WESNCALEGENDTRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON
20-279801/26/23MTRTRW
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-0227162030 PM VOL. WITH COUNTY & CITY PROJECT & LOS AAAAAAABAAAABBCVOLUMES = FIGURE 16 + FIGURE 10TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTONWESNCALEGEND 20-279801/26/23MTRTRW
Whipple Consulting Engineers, Inc. 49 Ponderosa Ridge
Horizon Year Traffic Impact Analysis (Buildout + 5 Years) W/ Background & Growth
The Horizon Year analysis is a requirement of the project per the COSV street standards as the
project is expected to proceed in phases, take more than 6 years to complete. Level of Service
calculations for the Year 2035 conditions assumed that the existing traffic volumes as shown on
Figures 3 & 4 experience an increase above the existing volumes at the established background
rate. Three scenarios were examined for the year 2035 analysis. The first scenario assumes that
the development has not moved forward and analyzes the scoped intersections with the
background growth rate and the background project trips as shown on Figures 5 & 6.
The second scenario assumes that the Ponderosa Ridge County project has moved forward and
analyzes the scoped intersections with the background growth rate, the background projects, and
the Ponderosa Ridge County project trips as shown on Figures 7 & 8.
The third scenario assumes that the Ponderosa Ridge City project has moved forward and
analyzes the scoped intersections with the background growth rate, the background projects, the
Ponderosa Ridge County as background and the Ponderosa Ridge City project trips as shown on
Figures 9 & 10. These scenarios will allow a determination to be made as to what the future
conditions may be both with and without the two projects.
Whipple Consulting Engineers, Inc. 50 Ponderosa Ridge
Year 2035 without the Project W/ Background and Growth
This scenario assumes that the developments have not moved forward. The traffic volumes for
this condition include the existing traffic, as shown on Figures 3 & 4, multiplied by the
background growth rate, plus the traffic from the background projects as shown on Figures 5 &
6. Please see Figures 17 & 18 for the traffic volumes used for this scenario. A summary of the
Level of Service results are shown in Table 9. This scenario creates a future year baseline that
allows for a direct comparison of the with project scenario.
Table 8 – Year 2035 Level of Service, without the Project W/ Background & Growth (Figures
17&18)
INTERSECTION
(S)ignalized
(U)nsignalized
AM Peak Hour PM Peak Hour
Delay
(sec) LOS Delay
(sec) LOS
44th Avenue & Schafer Branch Road U 8.4 A 8.4 A
44th Avenue & Ponderosa Lane U 8.5 A 8.4 A
44th Avenue & Locust Road U 8.9 A 8.8 A
44th Avenue & Farr Road U 8.7 A 8.6 A
45th Avenue & Farr Road U 8.6 A 8.6 A
Cimmaron Drive & Woodruff Road U 8.2 A 7.1 A
44th Avenue & Woodruff Road U 10.0 A 9.8 A
Dishman-Mica Road & Schafer/University Road S 16.6 B 20.2 C
Cimmaron Drive & Schafer Road U 11.0 B 11.6 B
44th Avenue & Schafer Road U 7.6 A 7.8 A
Dishman-Mica Road & Bowdish Road S 16.6 B 15.5 B
44th Avenue & Bowdish Road U 8.6 A 8.8 A
Spokane County and the City of Spokane Valley have adopted level of service D as the
minimum acceptable level for signalized intersections and level of service E as the minimum
acceptable level for unsignalized intersections. As shown in Table 9, the intersections are
anticipated to operate at an acceptable level of service.
Intersection Queue Left and Right turn lanes
A review of the calculated queue lengths provided in the appendix under LOS calculations,
identified no deficiencies within the queue storage of the turn lanes.
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-02272035 AM VOLUME WITHOUT PROJECT & LOS VOLUMES = FIGURE 3 * BACKGROUND GROWTHAAAAAAABBTRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTONWESNCALEGEND17 20-279801/26/23MTRTRWAA BB
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-0227182035 PM VOLUME WITHOUT PROJECT & LOS VOLUMES = FIGURE 4 * BACKGROUND GROWTHAAAABAABBCTRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTONWESNCALEGEND 20-279801/26/23MTRTRWAA
Whipple Consulting Engineers, Inc. 53 Ponderosa Ridge
Year 2035 with Ponderosa Ridge County W/ Background and Growth
This scenario assumes that the Ponderosa Ridge County project has moved forward and is added
to the previously established baseline. The traffic volumes for this condition includes the traffic
volumes shown on Figures 17 & 18 and adds the Ponderosa Ridge County project trips as shown
on Figures 7 & 8. Please see Figures 19 & 20 for the traffic volumes used for this scenario. A
summary of the Level of Service results is shown in Table 10.
Table 9 – Year 2035 Level of Service, with Ponderosa Ridge County W/ Background &
Growth (Figures 19&20)
INTERSECTION
(S)ignalized
(U)nsignalized
AM Peak Hour PM Peak Hour
Delay
(sec) LOS Delay
(sec) LOS
44th Avenue & Schafer Branch Road U 8.4 A 8.4 A
Leonidas Lane (Access) & Schafer Branch Road U 8.4 A 8.3 A
Ellie Belle Bells Lane (Access) & Schafer Branch Road U 8.3 A 8.3 A
44th Avenue & Ponderosa Lane U 8.6 A 8.4 A
44th Avenue & Locust Rd U 9.3 A 9.1 A
44th Avenue & Farr Road U 9.0 A 8.6 A
Cimmaron Drive & Woodruff Road U 8.2 A 7.1 A
44th Avenue & Woodruff Road U 10.4 B 10.3 B
Dishman-Mica Road & Schafer/University Road S 16.8 B 20.8 C
Cimmaron Drive & Schafer Road U 11.4 B 12.1 B
44th Avenue & Schafer Road U 8.1 A 8.0 A
Dishman-Mica Road & Bowdish Road S 16.8 B 15.9 B
44th Avenue & Bowdish Road U 8.7 A 8.8 A
Spokane County and the City of Spokane Valley have adopted level of service D as the
minimum acceptable level for signalized intersections and level of service E as the minimum
acceptable level for unsignalized intersections.
As shown in Table 10, the intersections are anticipated to operate at an acceptable level of
service.
Intersection Queue Left and Right turn lanes
A review of the calculated queue lengths provided in the appendix under LOS calculations,
identified no deficiencies within the queue storage of the turn lanes.
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-02272035 AM VOLUME WITH COUNTY PROJECT & LOS19 AAAAAABAABBBVOLUMES = FIGURE 13 + FIGURE 7WESNCALEGENDTRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON
20-279801/26/23MTRTRWAA
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-0227202035 PM VOLUME WITH COUNTY PROJECT & LOS AAAAAABAABBCVOLUMES = FIGURE 14 + FIGURE 8TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTONWESNCALEGEND 20-279801/26/23MTRTRWAA
Whipple Consulting Engineers, Inc. 56 Ponderosa Ridge
Year 2035 with Ponderosa Ridge County & Ponderosa Ridge City W/ Background and Growth
This scenario assumes that Ponderosa Ridge County & Ponderosa Ridge City has both moved
forward and is added to the previously established baseline. The traffic volumes for this
condition includes the traffic volumes shown on Figures 19 & 20 and adds the Ponderosa Ridge
City project trips as shown on Figures 9 & 10. Please see Figures 21 & 22 for the traffic volumes
used for this scenario. A summary of the Level of Service results is shown in Table 11.
Table 10 – Year 2035 Level of Service, with Ponderosa Ridge County & City W/ Background
& Growth (Figures 21&22)
INTERSECTION
(S)ignalized
(U)nsignalized
AM Peak Hour PM Peak Hour
Delay
(sec) LOS Delay
(sec) LOS
44th Avenue & Schafer Branch Road U 8.4 A 8.4 A
Leonidas Lane (Access) & Schafer Branch Road U 8.4 A 8.3 A
Ellie Belle Bells Lane (Access) & Schafer Branch Road U 8.3 A 8.3 A
44th Avenue & Ponderosa Lane U 8.6 A 8.4 A
44th Avenue & Locust Road (Access) U 9.8 A 9.7 A
44th Avenue & Farr Road U 9.5 A 8.8 A
45th Avenue (Access) & Farr Road U 8.7 A 8.7 A
47h Avenue (Access) & Farr Road U 8.6 A 8.8 A
Cimmaron Drive & Woodruff Road U 8.2 A 7.1 A
44th Avenue & Woodruff Road U 11.2 B 11.1 B
Dishman-Mica Road & Schafer/University Road S 17.3 B 22.2 C
Cimmaron Drive & Schafer Road U 12.1 B 13.0 B
44th Avenue & Schafer Road U 8.1 A 8.6 A
Dishman-Mica Road & Bowdish Road S 17.2 B 16.4 B
44th Avenue & Bowdish Road U 8.7 A 8.9 A
Spokane County, the City of Spokane Valley, and the WSDOT have adopted level of service D
as the minimum acceptable level for signalized intersections and level of service E as the
minimum acceptable level for unsignalized intersections.
As shown in Table 11, the intersections are anticipated to operate at an acceptable level of
service.
Intersection Queue Left and Right turn lanes
A review of the calculated queue lengths provided in the appendix under LOS calculations,
identified no deficiencies within the queue storage of the turn lanes.
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-02272035 AM VOL. WITH COUNTY & CITY PROJECT & LOS21 AAAAAAABAAAABBBVOLUMES = FIGURE 17 + FIGURE 9WESNCALEGENDTRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTON
20-279801/26/23MTRTRW
FIGUREDRAWN:DATE:PROJ #:
APPROVED:WCE
WHIPPLE CONSULTING ENGINEERS
21 S. PINES ROAD
SPOKANE VALLEY, WA 99206
PH: 509-893-2617 FAX: 509-926-0227222035 PM VOL. WITH COUNTY & CITY PROJECT & LOS AAAAAAABAAAABBCVOLUMES = FIGURE 18 + FIGURE 10TRAFFIC IMPACT ANALYSISPONDEROSA RIDGE
9100 EAST 44TH AVENUE
SPOKANE, WASHINGTONWESNCALEGEND 20-279801/26/23MTRTRW
Whipple Consulting Engineers, Inc. 59 Ponderosa Ridge
ADDITIONAL ANALYSIS – SIGHT DISTANCE
Horizontal/Decision Sight Distance
The decision sight distance or horizontal sight distance of an intersection is essential in the safe
operation of an unsignalized intersection. For a vehicle stopped at an intersection on a minor
road, the decision to enter the intersection is dependent on the sight distance of the minor street
driver’s eye. Any obstructions within the sight distance triangles such as trees, bushes, fences, or
existing vertical curves would impair the driver’s ability to make a safe decision to enter the
intersection. Therefore, an analysis of the sight distance triangles was done to determine if there
are any objects within the sight triangles that may block the view of the driver.
This sight distance analysis includes the following intersections as requested by the City of
Spokane Valley.
44th Avenue & Locust Road
45th Avenue & Farr Road
47th Avenue & Farr Road
Decision Point
The decision point as described by AASHTO is the vertex of the Sight Distance triangles and is
the location of the driver in a stopped vehicle. The vertex of the sight triangle should be located
15 feet from the edge of the major road traveled way and 3.5 feet above the road surface. Per
AASHTO 3.2 Sight Distance, the driver’s eye within the passenger car, design vehicle is set at a
height of 3.5’ above the pavement surface, the target of the driver’s eye is typically an object that
measures 2’ from the pavement surface and represents the height of a vehicle’s headlights. Each
intersection was measured using the 3.5’ height and 15’ decision point from traveled way.
Intersection Sight distance
The posted speed limit for Farr Road is 25 MPH and 35 MPH for 44th Avenue. Table 7.7 from
the City of Spokane Valley Street Standards shows the 15’ requirement for distance from
travelway and the sight distance requirements for each direction. For 44th Avenue, the sight
distance is 390 ft. for a 35 MPH speed limit. For Farr Road, the sight distance is 280 ft. for the
25 MPH posted speed limit.
Whipple Consulting Engineers, Inc. 60 Ponderosa Ridge
Source: City of Spokane Valley Street Standards
As stated above, the distance from the travelway for all three intersections was 15’. However, the
sight distance for 45th Avenue and 47th Avenue was 280’. The sight distance for 44th Avenue was
390’ since the posted speed limit is 35 MPH.
44th Avenue & Locust Road
Photo 1: 44th Avenue and Locust Road looking east.
Whipple Consulting Engineers, Inc. 61 Ponderosa Ridge
Photo 2: From 15’ Decision Point looking east for right turn movement.
Photo 3: From 15’ Decision Point looking west for left turn movement.
44th Avenue and Locust Road Conclusion
For the right and left turn movements, there are no visible sight obstructions. There is sight
distance available to meet the City of Spokane Valley standard.
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45th Avenue & Farr Road
Photo 4: 45th Avenue and Farr Road looking south.
Photo 5: 15’ from traveled way looking south for right turn movement.
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Photo 6: 15’ From traveled way looking north for left turn movement.
45th Avenue and Farr Road Conclusion
For the left turn movement, there is sight distance available to meet the City of Spokane Valley
requirements. For the right turn movement, there is a sight obstruction, and the 280 ft. cone was
not visible. It is recommended to trim the tree within the right of way to secure better sight
distance.
Whipple Consulting Engineers, Inc. 64 Ponderosa Ridge
47th Avenue & Farr Road
Photo 7: 47th and Farr Road looking south.
Photo 8: 15’ from traveled way looking south for right turn movement.
Whipple Consulting Engineers, Inc. 65 Ponderosa Ridge
Photo 9: 15’ From traveled way looking north for left turn movement.
47th and Farr Conclusion
For the right and left turn movements, there are no visible sight obstructions. There is sight
distance available to meet the City of Spokane Valley standard.
Sight Distance Analysis Conclusion
It is concluded that there is sufficient sight distance available at all existing and proposed
locations provided that the right-of-way is kept clear from vegetation.
Whipple Consulting Engineers, Inc. 66 Ponderosa Ridge
CONCLUSIONS & RECOMMENDATIONS
Conclusions
This Traffic Impact Analysis (TIA) has reviewed and analyzed the study area per the County
project scope established by Spokane County and the City of Spokane Valley with public
scoping meeting. Based upon the analysis, field observations, assumptions, methodologies, and
results which are provided in the body of this report, it is concluded that the development of the
proposed projects will generate new trips on the existing transportation system and that those
trips, while affecting Level of Service (LOS), will not degrade the LOS below acceptable levels
for the buildout (2030) and the buildout + 5 years (2035). This conclusion was reached and has
been documented within the body of this report.
Under the existing conditions, all intersections are currently operating at an
acceptable level of service.
For the year 2030 with background without projects scenario, all intersections
are anticipated to continue to operate at an acceptable level of service.
For the year 2030 with background with Ponderosa Ridge County scenario, all
intersections are anticipated to continue to operate at an acceptable level of
service.
For the year 2030 with background with Ponderosa Ridge County &
Ponderosa Ridge City scenario, all intersections are anticipated to continue to
operate at an acceptable level of service.
For the year 2035 with background without projects scenario, all intersections
are anticipated to continue to operate at an acceptable level of service.
For the year 2035 with background with Ponderosa Ridge County scenario, all
intersections are anticipated to continue to operate at an acceptable level of
service.
For the year 2035 with background with Ponderosa Ridge County &
Ponderosa Ridge City scenario, all intersections are anticipated to continue to
operate at an acceptable level of service.
Additional Analysis – Sight Distance there is sufficient sight distance available
at all existing and proposed locations provided that the right-of-way is kept clear
from vegetation.
Recommendations
Based upon the conclusions within this study, the proposed projects are recommended to
complete all required conditions of approval and should be allowed to move forward without
further traffic analysis, or offsite mitigation.