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Chapter 3: Analyzing Data <br />To guide decision-making and prioritize capital and programmatic investments, the CSAP draws on a robust analysis of collision history, <br />traffic volumes, travel speeds, roadway characteristics and other contextual variables, and intersection performance. This data-informed <br />approach helps identify patterns, higher-risk conditions, and opportunities for proactive safety and mobility improvements. <br />* 85th percentile speeds collected October 2024. <br />Collision Trends <br />Between 2014 and 2023, 107 collisions were <br />reported in Snoqualmie Pass, including three that <br />resulted in death or serious injury. Most collisions <br />occurred on SR 906 or the I-90 ramps, with 60% <br />occurring during the winter months when snow and <br />ice create hazardous conditions and Snoqualmie <br />Pass experiences a surge in visitors for ski season. <br />Speeding, distracted driving, and midblock collisions <br />were common contributing factors for both winter <br />and summer seasons. <br />Volume & Speed Trends <br />In addition to collision data, traffic volume and <br />speed data were analyzed to assess current roadway <br />conditions and understand how capacity constraints <br />may impact safety and performance in Snoqualmie <br />Pass. Data was collected during two study periods— <br />October 2024 and February 2025. <br />Traffic volumes spiked during peak recreation <br />periods, particularly near I-90 interchanges and key <br />intersections. While capacity analysis indicated that <br />intersections operated at acceptable levels of service <br />(LOS) with relatively limited delays in both October <br />and February study periods, field observations and <br />community feedback revealed that this analysis <br />represents only a snapshot in time and does not <br />fully capture the lived experience of residents and <br />visitors. On-the-ground observations during a <br />holiday weekend highlighted steadily increasing <br />congestion, high levels of street friction, and <br />conditions that contribute to safety risks, including <br />vehicles and trucks parking along SR 906, people <br />walking in narrow shoulders and along the traveled <br />way, unmarked pedestrian crossings, insufficient <br />parking supply, and driver confusion during peak <br />periods. Analysis of speed data revealed observed <br />speeds exceeding posted limits by up to 18 mph <br />along some segments of SR 906.* High vehicle <br />speeds are a concern given that vehicle speeds <br />greatly increase both the likelihood of a crash and <br />the severity of the outcome. <br />The data analysis confirms that there are persistent <br />infrastructural, behavioral, and seasonal challenges <br />that require targeted safety and mobility strategies in <br />Snoqualmie Pass. <br />Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec <br />26 <br />21 <br />7 <br />1 2 <br />6 7 <br />2 <br />5 <br />20 <br />55 <br />Collision <br />Type <br />2014 - 2023 <br />72% <br />3% <br />25% <br />Killed or Serious Injury <br />(KSI) Collisions <br />Three Collisions (3%) <br />Suspected Minor Injury <br />or Possible Injury Collisions <br />27 Collisions (25%) <br />Property Damage Only <br />(PDO) Collisions <br />77 Collisions (72%) <br />67 of 107 <br />Collisions (63%) <br />occurred during the winter months <br />SpeedingSpeeding Distracted <br />Driving <br />Distracted <br />Driving <br />Midblock <br />Collision <br />Midblock <br />Collision <br />Common <br />Contributing Factors <br />Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec <br />26 <br />21 <br />7 <br />1 2 <br />6 7 <br />2 <br />5 <br />20 <br />55 <br />Collision <br />Type <br />2014 - 2023 <br />72% <br />3% <br />25% <br />Killed or Serious Injury <br />(KSI) Collisions <br />Three Collisions (3%) <br />Suspected Minor Injury <br />or Possible Injury Collisions <br />27 Collisions (25%) <br />Property Damage Only <br />(PDO) Collisions <br />77 Collisions (72%) <br />67 of 107 <br />Collisions (63%) <br />occurred during the winter months <br />SpeedingSpeeding Distracted <br />Driving <br />Distracted <br />Driving <br />Midblock <br />Collision <br />Midblock <br />Collision <br />Common <br />Contributing Factors <br />8Kittitas County | Snoqualmie Pass Comprehensive Safety Plan