Title
Department of Transportation recommending the Board adopt and authorize the Chair to sign Resolution 092-2021 adding and amending speed restrictions on Greenstone Road.
FUNDING: Road Fund (100%).
Body
DISCUSSION / BACKGROUND
Department of Transportation, Maintenance and Operations Division (Transportation) conducted a speed survey on Greenstone Road from 150 feet north of Greenstone Cutoff northerly to the United States Highway 50 eastbound on and off ramps due to a change in roadway characteristics as a result of the recently completed Capital Improvement Project #77137, which replaced the bridge at Slate Creek and straightened out the curve adjoining the bridge.
Greenstone Road, segment 1 in the speed survey, currently displays a speed restriction between milepost 0.69 and 1.42 of forty-five (45) miles per hour. The existing speed restriction is sanctioned by Resolution No. 150-2016. Field review and data indicate that the existing speed zone on Greenstone Road between milepost 0.69 and 1.42 should remain unchanged. The reason centers on the fact that the newly measured values of the 85th percentile and the ten (10) mile per hour pace are still within the parameters of the existing speed limit. Therefore, the current postings should remain the same.
Greenstone Road, segment 2 in the speed survey, from milepost 0.16 to 0.69 is the segment that was affected by Capital Improvement Project #77137, which replaced the bridge at Slate Creek and straightened out the curve adjoining the bridge. This segment has a speed restriction of 55 miles per hour. Field review and data indicate that the newly measured 85th percentile value was recorded at forty-three (43) miles per hour. The existing 85th percentile speed of forty-three (43) miles per hour, justifies, in accordance with California Manual on Uniform Traffic Control Devices, a radar enforced forty-five (45) mile per hour speed zone.
Based on California Vehicle Code, Section 22358, which allows local authorities to establish speed limits based on an "Engineering and Traffic Survey," the West Slope Traffic Advisory Committee held a meeting on May 19, 2021, and voted unanimously to establish a forty-five (45) mile per hour speed restriction on Greenstone Road from 150 feet north of Greenstone Cutoff northerly to the United States Highway 50 eastbound on and off ramps.
The following is the final recommendation that was approved by the West Slope Traffic Advisory Committee:
DELETE:
Resolution No. 150-2016
"(gg) Greenstone Road (No. 7) forty-five (45) miles per hour from 750 feet south of Davidson Road northerly to the US Hwy 50 EB On/Off Ramps."
ADD:
"(gg) Greenstone Road (No. 7) forty-five (45) miles per hour from 150 feet north of Greenstone Cutoff northerly to the US Hwy 50 EB On/Off Ramps."
ALTERNATIVES
The Board could choose to not agree with the West Slope Traffic Advisory Committee's decision and leave the current speed restrictions on Greenstone Road.
PRIOR BOARD ACTION
N/A
OTHER DEPARTMENT / AGENCY INVOLVEMENT
Traffic Advisory Committee and County Counsel
CAO RECOMMENDATION / COMMENTS
Approve as recommended.
FINANCIAL IMPACT
Installation of speed limit signs on Greenstone Road from 150 feet north of Greenstone Cutoff to 750 feet south of Davidson Road is estimated at $1,400. Funding to complete the work is included in the Fiscal Year 21/22 recommended budget.
CLERK OF THE BOARD FOLLOW UP ACTIONS
1) The Clerk will obtain the Chair's signature on one (1) original of the Resolution.
2) The Clerk will forward one (1) copy of the Resolution to Transportation, Maintenance and Operations Division, attention Ashley Johnson.
STRATEGIC PLAN COMPONENT
Infrastructure and Public Safety
CONTACT
Rafael Martinez, Director
Department of Transportation