Atherton Municipal Code Ch. 10.06 Speed Limits

Sections:

• 10.06.010 Purpose. 10.06.020 Definitions. 10.06.030 Setting prima facie speed limits.

• 10.06.040 Findings for speed limit reduction pursuant to California Vehicle Code Section 22358.7.

• 10.06.050 Declared prima facie speed limits.

A. The state of California has asserted broad authority over, and a statewide interest in, the entire field of regulating vehicles and traffic, as set forth in the California Vehicle Code Section 21.

B. The state has established a set of prima facie speed limits applicable to various classes of roadway types, districts and locations (see California Vehicle Code Sections 22348 through 22366). Through California Vehicle Code Sections 22357 and 22358, the state has expressly authorized the town to establish, by ordinance, declared speed limits that differ from the prima facie speed limits set under state law if, based on traffic and engineering surveys, the declared speed limit would facilitate the orderly movement of vehicles and traffic, and would be reasonable and safe.

C. The intent of this chapter is to implement the town’s authority to establish declared speed limits when supported by engineering and traffic surveys and to respond to safety and use of the road by people driving, walking, and bicycling. (Ord. 674 § 1, 2025)

A. “Declared speed limit” means the speed limit for individual streets and roadway segments determined and declared by the city council in accordance with this chapter, as authorized by the California Vehicle Code. The term “declared speed limit” (as used in this chapter) shall include the “declared prima facie speed limit” or “maximum speed limit” (as used in California Vehicle Code Section 22357), or the “prima facie speed limit” (as used in California Vehicle Code Sections 22358, 22358.3 and 22358.4).

B. “Prima facie speed limits” means the default speed limits for streets and highways established under California State law, as generally set forth in the California Vehicle Code, particularly Section 22348 et seq., unless amended under this chapter.

• C. “Safety corridors” means streets as defined in California Vehicle Code Section 22358.7. (Ord. 674 § 1, 2025)

A. The city council may determine and declare speed limits lower than the prima facie speed limits for any particular street or roadway segment if the city council determines, upon the basis of an engineering and traffic survey, that the prima facie speed limit is more than is reasonable or safe, and that the declared speed limit is most appropriate to facilitate the orderly movement of traffic, and is reasonable and safe.

B. The city council may determine and declare speed limits lower than the speed limit identified by an engineering and traffic survey by reducing speeds by an additional five miles per hour in areas defined as a “safety corridor” or near land uses that generate a high concentration of pedestrians and bicyclists (California Vehicle Code Section 22358.7). For speed limits reduced pursuant to California Vehicle Code Section 22358.7, the town shall issue only warning citations for violations exceeding the speed limit by ten miles per hour or less for the first thirty days that a lower speed limit is in effect. (Ord. 674 § 1, 2025)

A. The following road segments are eligible for a five mile per hour reduction pursuant to California Vehicle Code Section 22358.7 because the road segment is either a safety corridor or generates high concentrations of bicyclists or pedestrians (as specified in California Vehicle Code Section 22358.7), and the speed limit following the engineering and traffic study is still more than reasonable or safe. For each road segment speed limit lowered pursuant to California Vehicle Code Section 22358.7, the findings that support the reduction are listed below:

1. Middlefield Road. Middlefield Road is a designated safety corridor in the town of Atherton due to its accident history, and the significant bicycle and pedestrian traffic associated with Encinal Elementary School and Menlo-Atherton High School. Middlefield Road fronts multiple schools and has limited street lighting at night. Middlefield Road has been designated in the High Injury Network listings in the San Mateo County C/ CAG Countywide and Town of Atherton Local Roadway Safety Plans, and is listed in the San Mateo County Safe Routes to School Youth-Based High Injury Network;

2. Valparaiso Avenue. Valparaiso Avenue is a designated safety corridor in both the Town of Atherton and the City of Menlo Park. Valparaiso Avenue carries significant bicycle and pedestrian traffic associated with

Menlo School and Sacred Heart Schools. Valparaiso Avenue has been designated in the High Injury Network listings in the San Mateo County C/CAG Countywide and Town of Atherton Local Roadway Safety Plans, and is listing in the San Mateo County Safe Routes to School Youth-Based High Injury Network. Valparaiso Avenue is shared jurisdictionally with the city of Menlo Park, which has previously designated the street as a safety corridor and reduced the speed limit to twenty-five miles per hour. (Ord. 674 § 1, 2025)

No person shall drive a vehicle at a speed greater than the declared speed limit for the street segment:

(Ord. 674 § 1, 2025)