Supervisors approve radar enforcement for Olive Hill Road

The San Diego County Board of Supervisors certified the speed limits on Olive Hill Road for radar enforcement.

The supervisors’ 5-0 vote Oct. 10 ratified an Aug. 3 recommendation of the county’s Traffic Advisory Committee. In addition to endorsing radar enforcement of the 40 mph speed limit from Mission Road to Mile Post 4 (between White Horse Lane and Futurity Lane), the 50 mph speed limit from Mile Post 4 to Morro Hills Road, and the 45 mph speed limit from Olive Hill Road to Morro Hills Road, the TAC had also recommended additional speed limit signs within the 45 mph segment which has an accident rate more than two and a half times the state average for similar roads. The installation of additional speed limit signs may be handled by the county’s Department of Public Works without Board of Supervisors approval.

In order for a speed limit to be enforceable by radar, a speed survey must show that the speed limit is within five mph of the 85th percentile speed, although the speed limit can be reduced by five mph from that increment if findings of special circumstances not apparent to a typical motorist are made.

The speed limits on Olive Hill Road have been posted since 1990 but had never been certified for radar enforcement. Olive Hill Road is a striped two-lane through highway and is classified as a Light Collector on the county’s Mobility Element network. Edge striping is painted along both sides of the road.

The 1.4-mile segment of Olive Hill Road between Mission Road and Mile Post 4 varies in width from 26 feet to 41 feet. In July 2012, the county’s Department of Public Works estimated a two-way average daily volume of 7,440 vehicles on the road north of Mackey Drive. The same location had average daily volumes of 6,080 vehicles during an April 2002 traffic survey and 4,580 vehicles based on an October 1991 survey.

A November 1991 speed survey taken 850 feet south of Mackey Drive indicated an 85th percentile of 48.8 mph with 75.2 percent of vehicles in a 39-48 mph pace. The next speed survey at that location was taken during the afternoon of Feb. 29, 2012. The 215 vehicles had an 85th percentile speed of 43.0 mph with 64.2 percent of drivers traveling within a 33-42 mph pace. The slowest of the vehicles was driving 19 mph while the two fastest approached the speed survey location at 52 mph. The most common speed, with 21 drivers, was 41 mph while 20 drivers were traveling at 40 mph.

During the two-year period from March 1, 2010, to Feb. 29, 2012, the segment between Mission Road and Mile Post 4 had 12 reported collisions, including five which involved injury, for an accident rate of 1.58 per million vehicle miles. The statewide average for similar roads is 1.30 per million vehicle miles.

The 1.9-mile segment from Mile Post 4 to Morro Hills Road varies in width between 27 and 34 feet. The last traffic survey was taken in August 2008 at Burma Road and indicated a two-way average daily volume of 3,980 vehicles. The July 2004 traffic survey at that location produced a two-way average daily volume of 3,730 vehicles while the December 1989 traffic survey indicated a daily average of 2,990 vehicles.

The speed surveys for that segment were taken 1,040 feet north of Del Valle Drive. The September 1991 survey resulted in an 85th percentile of 52.1 mph with 56.3 percent of drivers within a 39-48 mph pace. The survey in the early afternoon of Feb. 28, 2012, involved 291 vehicles at an 85th percentile speed of 50.0 mph and with 54.0 percent within a 38-47 mph pace. A driver at 21 mph was the slowest, two vehicles traveling 58 mph were the fastest, and the 21 drivers at 40 mph and 20 drivers at 39 mph made those speeds the most common. The segment’s only reported collision between March 1, 2010, and Feb. 29, 2012, did not involve an injury.

The segment of Olive Hill Road from Morro Hills Road to State Route 76 is 2.1 miles. The road width varies from 21 to 48 feet. The traffic surveys taken south of Puerta Del Sol had two-way average daily volumes of 3,030 vehicles in February 2012, 3,180 vehicles in April 2002, and 1,660 vehicles in October 1986.

The September 1991 speed survey 1,730 feet north of State Route 76 had an 85th percentile speed of 49.0 mph with 64.0 percent of drivers traveling within a 41-50 mph pace. The next survey at that location was taken on the morning of Feb. 28, 2012, and determined the speeds of 516 vehicles. The 85th percentile speed was 46.0 mph with 72.9 percent of drivers within a 37-46 mph pace. The fastest speed, with two drivers, was 55 mph while the slowest speed, with one driver, was 21 mph. The most common speeds were 41 mph with 46 drivers and 42 mph with 44 drivers.

The 2.1 miles of Olive Hill Road between Morro Hills Road and State Route 76 experienced 17 reported collisions, including six which involved injury, between March 1, 2010, and Feb. 29, 2012. That equates to an accident rate of 3.66 per million vehicle miles. The statewide average for similar roads is 1.37 per million vehicle miles.