Radar enforcement coming to Alvarado Street

The county’s Traffic Advisory Committee recommended that the 35 mph speed limit on Alvarado Street between Vine Street and Stage Coach Lane be certified for radar enforcement.

The TAC’s unanimous voice vote Sept. 13 sends the recommendation to the San Diego County Board of Supervisors. The county supervisors can ratify, overturn, or amend a TAC recommendation. An ordinance introduction and first reading is scheduled for the Dec. 4 meeting of the Board of Supervisors. Approval of the introduction and first reading would create a Jan. 8, 2014, date for the second reading and adoption. The ordinance allowing for radar certification would thus go into effect on Feb. 7, 2014.

“Hopefully it will have a little benefit,” said TAC secretary Kenton Jones.

A separate TAC unanimous voice vote Sept. 13 recommended recertification for radar enforcement of the adjacent section of Alvarado Street covering the 1.3 miles from Stage Coach Lane to Live Oak Park Road. Because that segment is already certified for radar and no change would be necessary, Board of Supervisors ratification Dec. 4 would require no further action until the next recertification cycle.

In order for a speed limit to be enforceable by radar, a speed survey must show that the speed limit is within an adjacent 5 mph increment to the 85th percentile speed. “We can round up. We can round down,” Jones said.

The speed limit can be reduced by an additional 5 mph if findings of special circumstances not apparent to a typical motorist are made, although the TAC made no such findings for either segment of Alvarado Street. Periodic recertification, along with a supporting speed survey, is required for continued radar enforcement. “Once every seven years we go out there with a radar gun,” Jones said.

The county’s Department of Public Works itself does not perform the speed surveys; contractors measure vehicle speeds over a two-hour period. Because the speed surveys are for only a single day, changes in 85th percentile speeds over seven years are not necessarily gradual. “They’re snapshots on an average standard day,” Jones said.

Alvarado Street between Vine Street and Stage Coach Lane covers 1.36 miles. The 35 mph speed limit was initially posted in 1970 but had never been certified for radar. The California Highway Patrol’s Oceanside office requested that the TAC consider radar enforcement due to complaints the law enforcement agency has received from citizens about speeding motorists.

Alvarado Street between Vine and Stage Coach ranges in width between 29 and 44 feet. It is a striped two-lane highway with edge striping on both sides of the road and is classified as a Light Collector on the county’s Mobility Element network. An August 2013 traffic survey east of Ellis Lane indicated a two-way average daily volume of 4,830 vehicles. The previous traffic survey on that segment was taken in August 1987 west of Stage Coach Lane and produced a two-way average daily volume of 2,750 vehicles.

Between April 30, 2008, and April 30, 2013, the segment of Alvarado Street between Vine and Stage Coach had 23 reported collisions, including six involving injuries and two involving pedestrians. The accident rate per million vehicle miles of 1.92 compares favorably with the statewide average of 2.39 for similar suburban roads but not so favorably if Alvarado Street is considered to be a rural rolling road, for which the statewide average is 1.22 collisions per million vehicle miles.

The first-ever speed survey for Alvarado Street between Vine Street and Stage Coach Lane was conducted 240 feet east of Ellis Lane on Aug. 20, 2013, by Department of Public Works student intern Geoffrey Retemeyer. The speed survey lasted from 10:22 a.m. to 11:13 a.m. and included 110 vehicles whose 85th percentile was 37.9 mph. The 10 mph pace was 29-38 mph with 76 drivers, or 69 percent, within that pace. The most common speeds, with 10 drivers apiece, were 31, 32, and 37 mph. A motorist at 44 mph was the fastest while the slowest two vehicles traveled at 24 mph. Only 10 of the vehicles crossed the survey point at 40 mph or faster with four of those being measured at 40 mph.

The radar certification of Alvarado Street between Vine and Stage Coach allows for continuous radar certification of the same speed limit on Alvarado. The segment between Stage Coach Lane and Live Oak Park Road is 28 feet wide; the two-lane roadway has edge striping on both sides and is not classified on the Mobility Element network. The traffic survey was taken west of South Emilia Lane; the June 2013 two-way average daily volume of 1,860 vehicles is a decline from the 2,680 vehicles in April 2002 and the 2,120 vehicles in March 2000.

The lower average volume was used for the accident rate, thus producing a rate more than four times the statewide average. The 24 reported collisions between April 30, 2008, and April 30, 2013, included eight with injuries and one involving a pedestrian. Although the segment accident rate is 5.44 per million vehicle miles and the statewide average is 1.33 per million vehicle miles, a review of the collision locations and causes did not indicate that any road-based corrective action could be taken to reduce the number of accidents.

The 35 mph speed limit on Alvarado between Stage Coach Lane and Live Oak Park Road was first posted in 2000 and was certified for radar at that time. It was first recertified in 2006, when the 85th percentile speed 100 feet west of South Emilia Lane was 34.4 mph with 78.6 percent of the vehicles traveling within a 27-36 mph pace.

National Data and Surveying Services conducted a speed survey at South Emilia Lane on Aug. 14, 2013, between 9 a.m. and 11 a.m. The 122 vehicles had an 85th percentile speed of 36.0 mph. The 10 mph pace remained at 27-36 mph with 97 vehicles, or 80.0 percent, within that pace. The most common speed, with 18 drivers, was 33 mph, while 11 drivers apiece made 30 mph, 32 mph, and 34 mph the second most common speed and ten motorists crossed the survey point at 31 mph. The fastest vehicle was measured at 42 mph with two vehicles traveling at 41 mph and one motorist driving at 40 mph. One driver traveled 22 mph, although the six next slowest motorists had speeds of 26 mph.