Supervisors approve Old River Road, South Mission Road 35 mph speed limits

Joe Naiman

Village News Reporter

The San Diego County Board of Supervisors approved a 35 mph speed limit for Old River Road between Camino Del Rey and Golf Club Drive and retention of the 35 mph speed limit on South Mission Road from 860 feet south of Pepper Tree Lane to Hill Avenue.

A 4-0 vote March 1, with Terra Lawson-Remer absent, approved the first reading and introduction of the speed limit ordinances. A 4-0 vote March 15 with Lawson-Remer absent approved the second reading and adoption.

The new speed limit on Old River Road will become enforceable April 14, although the county’s Department of Public Works can erect signage earlier. The supervisors’ actions also approved re-certifying the South Mission Road speed limit for radar enforcement and certifying the Old River Road speed limit for radar enforcement.

Old River Road between Camino Del Rey and Golf Club Drive measures 0.39 miles. There is currently no posted speed limit, although by state law the maximum speed for a two-lane road is 55 mph and the school zone by Bonsall Elementary School triggers a 25 mph speed limit when children are present.

Camino Del Rey has a 45 mph speed limit. Camino Del Rey and Old River Road are connected at a “Y” intersection. Old River Road south of Golf Club Drive qualifies as a residential area with an automatic 25 mph speed limit.

Although the segment between Camino Del Rey and Golf Club Drive has no posted speed limit, that portion has curve speed advisory signs. Old River Road is a two-lane road with a 26-foot pavement width. The roadway is striped with a no passing centerline and white edge lines on both sides. The mobility element of the county’s general plan classifies Old River Road as a Light Collector.

A traffic survey 800 feet south of Camino Del Rey was taken in April 2022. The 1,491 southbound and 1,476 northbound vehicles produced an average daily traffic volume of 2,967 drivers. Between June 1, 2019, and May 31, 2022, Old River Road between Camino Del Rey and Golf Club Drive had three reported collisions, none of which involved an injury. The collision rate of 2.37 collisions per million vehicle miles exceeds the statewide average of 1.60 per million vehicle miles for similar suburban conventional two-lane roads with speed limits less than 45 mph.

The collision rate higher than the statewide average was used for the recommendation to make the speed limit 35 mph rather than 40 mph. A February 2022 speed survey taken 130 feet south of Avenida De Las Vida had an 85th percentile of 40.8 mph with 68% of the 123 drivers within a 10 mph pace of 34‑43 mph. The most common speeds were 35 mph with 14 drivers, 38 mph with 12 motorists, and 36 mph with 11 drivers. The fastest motorist was clocked at 50 mph while the slowest vehicle was traveling 23 mph.

The Sept. 9 meeting of the county’s Traffic Advisory Committee included a recommendation for the 35 mph speed limit on Old River Road between Camino Del Rey and Golf Club Drive. The October 28 TAC meeting included the recommendation to retain the 35 mph speed limit on the 1.75 miles of South Mission Road from 860 feet south of Pepper Tree Lane to Hill Avenue.

The mobility element of the general plan classifies South Mission Road as a Major Road. South Mission Road from 860 feet south of Pepper Tree Lane to Hill Avenue is a four-lane divided highway with a pavement width ranging from 75 to 82 feet. The roadway is striped with a two-way left turn lane, lane striping, and intermittent parking lane and edge lines.

The signage along that part of South Mission Road includes school zone signage, signal ahead signs, pedestrian advisory signs, and school crossing signage. The road also has a flashing beacon to notify motorists about the school crossing at Elder Street. There are traffic signals at the intersections with Clemmens Lane, Ammunition Road, Aviation Road, Fallbrook Street, and Alvarado Street.

The 2015 speed survey utilized three locations. The 85th percentile 250 feet south of Ammunition Road was 34 mph with 85% of motorists traveling within a 27-36 mph pace. The motorists 250 feet south of Old Stage Road had an 85th percentile of 42 mph with 81% of drivers within a 32‑41 mph pace. The 85th percentile 300 feet south of Fallbrook Street was 40 mph with 76% of motorists driving within a 30-39 mph pace.

An October 2015 traffic survey taken 200 feet south of Fallbrook Street indicated 23,470 total vehicles consisting of 11,292 northbound and 12,178 southbound motorists. The 2022 estimated average daily volume was 25,480.

A total of 78 collisions, including 34 which involved injury, were reported on South Mission Road from 860 feet south of Pepper Tree Lane to Hill Avenue between June 1, 2019, and May 31, 2022. That creates an accident rate of 1.79 per million vehicle miles traveled. The statewide average for similar suburban divided four-lane roads with speed limits less than or equal to 55 mph is 1.25 per million vehicle miles.

Three speed surveys were taken on Oct. 12, 2022. The 201 drivers north of West College Street had an 85th percentile of 39.2 mph with 73% of motorists within a 10 mph pace of 29‑38 mph.

The speed survey 150 feet south of Fallbrook Street had 320 drivers whose 85th percentile was 33.8 mph with 81% within a 25-34 mph pace. The 85th percentile for the 210 motorists in the speed survey 400 feet south of Clemmens Lane was 38.4 mph and 79% of drivers were within a 30-39 mph pace. The speed zone 85th percentile was 38.8 mph with 76% of drivers within a pace of 30-39 mph.