2023-05-08-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: May 8, 2023 TOPIC: Thomas 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 Thomas Road (MP 0.00 to MP 1.51) BRIEFING SUMMARY: • A resident on Thomas Road requested a speed reduction on Thomas Road (MP 0.00 to MP 1.51) on December 29, 2022 • The speed study was conducted on April 11, 2023 to April 18, 2023 • Speed study data collected at MP 0.78 • Average daily traffic (ADT) of 150 vehicles, with 33 trucks (23%) • ADT distribution is 53% eastbound and 47% westbound • 85% speed at 40 Miles Per Hour (MPH) eastbound and 42 MPH westbound • Two crashes in the past five years BACKGROUND: Responding to a request received on December 29, 2022, to reduce the posted speed on Thomas Road, Public Works deployed traffic data collectors April 11, 2023 and collected through April 18, 2023. Traffic and speed data was collected at mile post 0.78. This road segment has 23 percent truck traffic within the average daily traffic distribution of vehicle size. Traffic at this location is split 53% eastbound and 47% westbound. Overall 85th percentile speed at this location is 41 MPH, with directional speeds of 40 MPH eastbound and 42 MPH westbound. DISCUSSION: 85th percentile speeds show traffic is operating at a speed less than the current speed limit of 50 MPH. The 85th percentile speeds suggest this roadway segment is more accommodating to a lower speed than the current posted speed limit. The roadway alignment includes horizontal curves beginning near mile post 0.75 through mile post