S. Coleman Road Traffic Analysis

The city has conducted a traffic analysis to address resident concerns regarding traffic complaints in S. Coleman Road related to past land development in Spokane County. Since 2020, multiple traffic evaluations have been completed.

Land Development: History and Overview

  • The Taylor Cottages preliminary plat approved by Spokane County in 2011 created 251 residential lots, of which 32 lots were expected to travel north on Coleman Road.
  • In 2018, the development modified the preliminary plat, realigning an internal street, which increased the lots expected to travel north on Coleman Road to 58 lots.
  • The connection to Coleman Road at 12th Avenue was constructed in 2021 and opened to the public in 2022.  
  • Between 100 and 300 vehicles per day travel area roadways.
  • The most common concerns raised by the public are on-street parking, speeding, intersection visibility, and right-of-way compliance for drivers yielding to each other. Additional stop or yield signs have been requested by residents in the city near the county development.
  • Two crashes have been reported in the last five years, both at 11th Avenue and Coleman Road, involving northbound vehicles hitting westbound vehicles.

Findings


PARKING

The city conducted a study to determine if a parking evaluation was needed on three segments of roadway:

SPEEDS

The city conducted a study to evaluate existing speeds along segments of S. Coleman, 11th and 12th avenues. The study area was broken down into three segments, all with a speed limit of 25 MPH in the residential area. The roads within the study area are intended for residential access and speeds are reflective of that. Learn more about the speed study.
FINDING: Average speeds on all three street segments were below posted speeds. No recommended action.

SIGHT DISTANCE

The city hired a consultant to complete a sight distance study for Coleman Road.  J-U-B ENGINEERS, Inc. performed sight distance evaluations at the intersections of Coleman Road and 9th, 10th, 11th, and 12th Avenues. The intersections on Coleman Road are uncontrolled and have sight distance triangles of 90 feet in each direction. 

  • Adequate intersection sight distance, crash history and roadway volume are federal regulation criteria for determining if stop or yield control should be installed at an intersection. The Manual on Uniform Traffic Control Devices (MUTCD), a federal document, governs the installation of traffic control devices, such as stop or yield signs. 
  • The Clearview Triangle is a measurement applied at intersections and driveways to ensure motorists and pedestrians have a clear view. . Sight blocks such as fences or vegetation shall be located outside of the clear view triangle, per Spokane Valley Municipal Code 22.70.020.

Specific findings for each intersection:

  • 9th Avenue at Coleman Road: Structures, fences, and vegetation are blocking portions of the 90-foot Clearview triangle on the northwest and southwest corners, requiring trimming of vegetation and potential modifications to fences. There have been no reported crashes at this intersection in the last 5 years. Given these findings, there is no documented safety issue and no change to intersection control is warranted.
  • 10th Avenue at Coleman Road: Structures, fences and/or vegetation are blocking portions of the 90-foot clear view triangle on the southeast and southwest corners, requiring trimming of vegetation and potential modifications to fences. There have been no reported crashes at this intersection in the last 5 years. Given these findings, there is no documented safety issue and no change to intersection control is warranted.
  • 11th Avenue at Coleman Road: A structure and landscaping are blocking a portion of the 90-foot clear view triangle on the southeast corner. There have been two reported crashes at this intersection in the last 5 years (May 2019 & May 2022), both involving a vehicle failing to yield the right-of-way. Based on the crash history, there is cause to evaluate sight distance and intersection control, though the crash threshold hasn’t been met to warrant a change to intersection control.  
    Given the low volume of Coleman Road and the position of 11th Avenue between two collector roadways, any traffic control change would be placed on the Coleman Road approaches.
  • 12th Avenue at Coleman Road: Fences are blocking a portion of the 90-foot  clear view triangle on the northeast and southeast corners, requiring modification. The have been no reported crashes at this intersection in the last 5 years. Given these findings, there is no documented safety issue and no change to intersection control is warranted.

The study identified significant modifications to private property may be required to meet clear view triangle sight distance requirements and comply with Spokane Valley Municipal Code 22.70.030. Findings are summarized in the Sight Distance Evaluation.

THE PATH FORWARD

Based on engineering studies, the only criteria Coleman neighborhood intersections meet to warrant stop signs are obstructions such as overgrown vegetation. These obstructions are on private property that limit the clear view of drivers. The city will work with property owners to correct the obstructions.

RESIDENT SURVEY

The city invites feedback regarding safety at intersections, speeds, yielding and sight distance from residents in the Coleman neighborhood. Please select the button below to take a survey or email input to traffic@spokanevalleywa.gov.