Board adopts first reading of speed‑limit ordinance after engineering surveys on Cement Hill, Mooney Flat and Donner Pass

Public Works presented engineering and traffic surveys and proposed changes to posted speed limits on Cement Hill Road, Mooney Flat Road and Donner Pass Road. Staff described radar‑box counts (3–5 days), calculation of 80th‑percentile speeds and rounding to the nearest 5 mph per the California Vehicle Code and the California MUTCD. The studies showed higher prevailing speeds on long sections of Mooney Flat and varying speeds along Donner Pass, prompting a recommended split of Donner Pass into multiple posted segments.

Robert Paderno (consultant) explained that Section 1 of Donner Pass (I‑80 to Soda Springs) produced an 80th‑percentile of 36.5 mph, which rounds to 35 mph and—after applying a 5‑ and additional 5‑mph reduction for roadway geometry and pedestrian/bicycle‑generating land uses—resulted in a recommended 25 mph posting for that segment. Other segments were set to 35–40 mph where appropriate. CHP representatives explained that engineering surveys are required before radar/lidar enforcement for prima facie speed limits and described enforcement resource considerations. The Board adopted the ordinance on first reading by roll call and scheduled second reading per normal ordinance process.