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Safety Report

This section provides a summary of the corridor’s five-year crash history (2016-2020). Analyzing crash data helps to identify locations that may need safety improvements, and to identify corridor-wide safety trends that may need to be addressed. WSDOT’s goal is to reduce traffic fatalities and serious injuries on Washington’s roadways to zero by the year 2030.

Corridor-wide Crashes

A graph showing breakdown of the corridor’s crash history. Between 2016 and 2020 there were 1,127 collisions, three of which were fatal. Nearly 800 of the collisions yielded no apparent injury
From 2016-2020, 1,127 crashes occurred along this segment of SR 99. Of these crashes,
nearly 30% resulted in some type of injury.
A color-coded map showing highlight which areas of SR 99 have a history of collision, and the comparative frequency of the collision. The north end of the corridor shows significantly higher incidence of collisions
This heatmap shows the concentration of all types of crashes along the SR 99 corridor.
A darker color indicates a higher concentration of crashes.

Corridor-wide Crash Types

A pie chart of corridor crash data showing the most common types of crashes that have occurred along the study corridor
  • Rear-end crashes were the most common crash type, representing 43% of all crashes. Rear end crashes tend to occur at low speeds and are less likely to cause injury than other crash types. Rear end crashes accounted for 6% of all fatal and serious injury crashes.
  • Left-Turn and Angle, or T-bone type crashes represented 26% of all crashes, and 31% of all injury crashes. 65% of these crashes occurred at driveway openings.
  • Though pedestrians and bicyclists were only involved in 3% of all crashes, they account for 73% of fatal and serious injury crashes.

Corridor-wide Pedestrian and Bicycle Crashes

  • 41% of all ped/bike crashes resulted in a fatality or serious injury.
  • 73% of fatal and severe ped/bike crashes occurred at night (including sunset and sunrise).
  • 66% of all, and 90% of fatal/severe, injury ped/bike crashes occurred when the pedestrian or bicyclist was crossing the road.
    – 58% of these crashes occurred outside of a marked crosswalk.
A bar chart of bicycle and pedestrian crash data showing how bicycle and pedestrian crashes are distributed along the corridor
This image shows the distribution of pedestrian and bicycle crashes throughout the study corridor. Crashes are mostly concentrated at signalized intersections.

Top Crash Locations

  • Airport Road Intersection
  • 148th Street Southwest intersection
  • North of Lincoln Way intersection

Location of bicycle and pedestrian crashes at Airport Road, 148th Street, and near Lincoln Way

A diagram showing the pedestrian crash locations at the Airport Road intersection. Most crashes involved pedestrians crossing in the crosswalk.
A diagram showing the bicycle crash locations at the Airport Road intersection. The crashes are concentrated at and just north of the intersection.
A diagram showing the bicycle crash locations at the 148th Street intersection. The crashes are concentrated at and just south of the intersection.
A diagram showing the bicycle crash locations at the Lincoln Way intersection. The crashes are concentrated at the intersection, and slightly to the north near the Community Transit bus stop.

Corridor-wide Left-turn and Angle Crashes

  • Left-turn and Angle, or T-bone type crashes represented 26% of all crashes, and 31% of all injury crashes. 34% of left-turn/angle crashes resulted in injury.
  • 65% of angle/left-turn crashes occurred at driveways:
    8% of these driveway crashes occurred at the Lynwood Food Mart shopping plaza entrance.
    – The remaining 92% occurred at various driveways throughout the corridor with no one driveway representing more than 4% of the crashes.
A bar chart of angle and left turn crash data showing how bicycle and pedestrian crashes are distributed along the corridor

The image above shows the distribution of angle and left turn crashes throughout the study corridor. These crashes are mostly concentrated near signalized intersections, with the exception of the 40th Street intersection and the Lynnwood Food Mart entrance driveway. The remaining crashes are distributed among driveway locations along the corridor.

Segment One: 164th Street Southwest to 148th Street Southwest

A map showing the limits of Segment One of the study corridor, highlighting key intersections and destinations

Top Crash Locations

  • 148th Street Southwest intersection
  • 164th Street Southwest intersection
  • 40th Ave West intersection
A pie chart showing the most common crash types within Segment One of the study corridor

Key trends

  • Two fatal crashes occurred in this segment, both occurring north of 156th Street Southwest.
  • 72% of the pedestrian and bicycle crashes in this segment occurred at the 148th Street intersection.
  • 25% of the angle and left-turn crashes in this segment occurred at the 40th Avenue West intersection.

Segment One: 148th Street Intersection

A pie chart showing the most common crash types at the SR 99 and 148th St SW intersection

Key Trends

  • 13% of corridor-wide fatal and severe injury crashes occurred at this intersection.
  • 21% of corridor-wide pedestrian and bicycle crashes occurred at this intersection.
  • 34% of all crashes and 50% of pedestrian and bicycle crashes at this intersection occurred at sunrise, sunset or at night.

Location of crashes that occurred at the 148th Southwest intersection

A diagram of crashes that have occurred at the 148th Street intersection. The most common crash types include rear-ends, sideswipes, and pedestrian crashes.

Segment Two: 148th Southwest to Lincoln Way

A map showing the limits of Segment Two of the study corridor, highlighting key intersections and destinations

Top Crash Locations

  • Lincoln Way intersection
  • Lynnwood Food Mart shopping plaza entrance
A pie chart showing the most common crash types within Segment Two of the study corridor

Key trends

  • Both of the pedestrian crashes within this segment occurred at the Lincoln Way intersection.
  • 37% of the angle and left-turn crashes in this segment occurred at the channelized left-turn into Lynwood Food Mart shopping plaza.

Segment Three: Lincoln Way to Airport Road

A map showing the limits of Segment Three of the study corridor, highlighting key intersections and destinations

Top Crash Locations

  • Airport Road intersection
  • Gibson Road intersection
A pie chart showing the most common crash types within Segment Three of the study corridor

Key trends

  • The Airport Road intersection accounts for 25% of all crashes within this segment.
  • There were five fatal and severe injury crashes within this segment, 80% of these crashes involved a pedestrian or bicyclist.

Segment Three: Airport Road Intersection

A pie chart showing the most common crash types at the SR 99 and Airport Road intersection

Key Trends

  • 33% ofcorridor-wide fatal and severe injury crashes occurred at this intersection.
  • 26% ofcorridor-wide pedestrian and bicycle crashes occurred at this intersection.
  • 38% of all crashes and 30% of pedestrian and bicycle crashes at this intersection occurred during sunrise, sunset or at night.
  • 70% of pedestrian and bicycle crashes at this intersection involved pedestrians and bicyclists crossing in the marked crosswalk.

Location of crashes that occurred at the Airport Road Intersection

One of two diagrams showing crashes that have occurred at the Airport Road intersection. The most common crash types include sideswipes, and angle crashes.
The second of two diagrams showing crashes that have occurred at the Airport Road intersection. The most common crash types include angle, pedestrian, and bicycle crashes.