2023-10-09-minutes-public-works-study-session

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KITTITAS COUNTY DEPARTMENT OF PUBLIC WORKS PUBLIC WORKS — BOARD OF COUNTY COMMISSIONERS STUDY SESSION STAFF REPORT STUDY SESSION DATE: October 9, 2023 TOPIC: No. 81 Road Speed Study Results ACTION REQUESTED: Schedule a Public Hearing receiving the Engineer's Report on the Request for Speed Reduction LEAD STAFF: Joshua Fredrickson RECOMMENDATION: Schedule a public hearing receiving the County Engineer's report on the request for speed reduction on No. 81 Road (MP 1.00 to MP 2.54) BRIEFING SUMMARY: • A resident requested a speed reduction on No. 81 Road (MP 1.00 to MP 2.54) on August 22, 2023. • The speed study was conducted on September 13, 2023, to September 20, 2023 • Speed study data collected at MP 1.32. • Average daily traffic (ADT) of 849 vehicles, with 270 trucks (32%). • ADT distribution is 50.0% northbound and 50.0% southbound. • 85% speed at 53.6 Miles Per Hour (MPH) northbound and 57.6 MPH southbound. • Seven crashes in the past five years. BACKGROUND: Responding to a request received on August 22, 2023, to reduce the posted speed on No. 81 Road between Vantage Highway and Snodgrass Road, Public Works deployed traffic data collectors September 13, 2023, and collected through September 20, 2023. The segment analyzed was from Vantage Highway to Lyons Road as the next main intersection. Traff c and speed data was collected at mile post 1.32. This road segment has 32 percent truck traffic within the average daily traffic distribution of vehicle size. Traffic at this location is split 50.0% northbound southbound. Overall 85`h percentile speed at this location is 55.6 MPH, with directional speeds of 53.6 MPH northbound and 57.6 MPH southbound. DISCUSSION: The overall 85th percentile speed show traffic is operating at a speed greater than the current posted speed limit of 50 MPH. The 8P percentile speeds suggest this roadway segment is more accommodating to speed than the current posted speed limit. The