Speed limit to remain 35 mph on S. Mission Road through town

The county's Traffic Advisory Committee recommended that the 35 mph speed limit on South Mission Road from 860 feet south of Pepper Tree Lane to Hill Street be recertified for radar enforcement.

Eleven members of the TAC were present at the March 11 meeting. Eight of those supported maintaining the 35 mph speed limit for the 1.73-mile section and recertifying that segment for radar enforcement while three abstained. The San Diego County Board of Supervisors is scheduled to hear the recertification May 11 and can ratify or overturn the TAC recommendation.

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. Periodic recertification, including a supporting speed survey, is required for continued radar enforcement and the county's Department of Public Works or a DPW contractor typically conducts speed surveys every seven years. The speed limit may be rounded either up or down from the 85th percentile speed. The speed limit may also be rounded down an additional 5 mph if findings are made that the road has conditions which would not be apparent to a motorist unfamiliar with the road.

The TAC continued the South Mission Road speed limit review from its Dec. 11 meeting. The portion of South Mission Road immediately south of the segment under consideration has a 50 mph speed limit, creating a 15 mph differential, and the TAC asked DPW to study the possibility of a 40 mph or 45 mph speed limit between the 50 mph and 35 mph segments. Additional speed surveys were taken between the two hearings and the TAC opted against a higher speed limit primarily due to lower 85th percentile speeds in the additional locations. "We had more data on the northern half," said TAC secretary Kenton Jones. "Now we have data on the northern and the southern."

South Mission Road from 860 feet south of Pepper Tree Lane to Hill Avenue is a four-lane through highway with a striped median. The segment has both residential and commercial usage and varies in width from 75 to 82 feet. South Mission Road is classified as a Major Road in the mobility element of the county's general plan.

The 24-hour traffic survey taken 200 feet south of Fallbrook Street on October 20, 2015, indicated 23,470 total vehicles consisting of 11,292 northbound and 12,178 southbound motorists. Between midnight and noon that Tuesday 3,108 southbound and 6,088 northbound vehicles crossed that survey point while between noon and midnight the segment was traveled by 8,184 northbound and 6,090 southbound vehicles. The previous traffic survey at that location was taken in October 2009 and resulted in an average daily volume of 23,540 vehicles.

A total of 52 collisions were reported on South Mission Road from 860 feet south of Pepper Tree Lane to Hill Avenue between July 31, 2013, and July 31, 2015. That creates an accident rate of 1.69 per million vehicle miles traveled. The statewide average for similar roads is 1.44 per million vehicle miles. Thirty-seven of those accidents were during daylight and the other 15 were at night. The 23 collisions which involved injury consisted of five in which a pedestrian was injured and 18 in which other injury occurred. All five pedestrian injury collisions were during daylight while 11 of the other injury collisions were during daytime and seven were at night.

In 2008 a speed survey conducted 140 feet north of West College Street indicated an 85th percentile speed of 42 mph with 75.4 percent of drivers traveling within a 34-43 mph pace. When the 35 mph speed limit was previously certified for radar enforcement the TAC made findings of an accident rate higher than the statewide average, significant pedestrian traffic including school-related pedestrian activity, and driveway density.

The 201 vehicles which crossed the survey point 140 feet north of West College Street on October 20, 2015, between 9:20 a.m. and 11:20 a.m. had an 85th percentile speed of 41 mph and 79 percent of those motorists were within a 32-41 mph pace. The most common speed was 34 mph with 30 vehicles while 20 vehicles apiece were traveling at 35 mph and 38 mph. The fastest vehicles were one at 50 mph and two apiece at 49 mph, 47 mph, 46 mph, and 45 mph. Three drivers traveling at 29 mph were the slowest motorists.

National Data and Surveying Services, which conducted the October 20 speed survey, took three additional speed surveys on January 8. A survey 250 feet south of Ammunition Road measured the speeds of the 104 vehicles which crossed that point from 9:00 a.m. to 11:00 a.m., a survey between 11:00 a.m. and 1:00 p.m. was taken 250 feet south of Old Stage Road and counted 133 vehicles, and a survey 300 feet south of Fallbrook Street involved 197 motorists and was taken from 11:10 a.m. to 1:10 p.m.

The 85th percentile for the survey 250 feet south of Ammunition Road was 34.0 mph with 85.0 percent of motorists traveling within a 27-36 mph pace. The 50th percentile speed was 31 mph and the most common speeds were 32 mph with 16 vehicles, 29 mph with 15 motorists, and 30 mph with 12 vehicles. The fastest motorist crossed the survey point at 42 mph and two vehicles were traveling at 40 mph. The slowest two drivers had speeds of 24 mph and four vehicles traveled at 25 mph.

The vehicles 250 feet south of Old Stage Road had an 85th percentile of 42.0 mph with 81 percent of drivers within a 32-41 mph pace and a 50th percentile of 37 mph. Fifteen drivers apiece crossed the survey point at 34 mph, 35 mph, 37 mph, and 38 mph. The fastest motorists were one traveling 48 mph and one driving at 47 mph while two motorists at 30 mph and two at 31 mph were the slowest.

The 85th percentile 300 feet south of Fallbrook Street was 40.0 mph with 76.0 percent of motorists driving within a 30-39 mph pace. The 50th percentile speed was 34 mph. The most common speed, with 27 drivers, was 34 mph while 18 motorists had speeds of 31 mph and 17 drivers were traveling at 36 mph. The fastest drivers were one apiece at 49 mph, 46 mph, and 45 mph. The slowest travel was by one motorist apiece at 23 mph and 25 mph and five drivers at 27 mph.

"Generally it looks like it's an appropriate speed limit," said county traffic engineer Zoubir Ouadah.

Ouadah noted that the accident rate has remained higher than the statewide average. "There is something in this roadway that the driver's not seeing," he said.

Although the official TAC recommendation did not include any warning signs, DPW has the authority to provide non-regulatory transition notices or other warning signs without Board of Supervisors approval and may utilize that option in the future.