APPENDIX A.1

SPEED LIMIT

“WHEN WILL A LOWER SPEED LIMIT BE POSTED ON MY STREET?”

A common belief is that posting a speed limit will influence drivers to drive at that speed.

The facts indicate otherwise.

Research conducted in many parts of this country over a span of several decades has shown that drivers are influenced more by the appearance of the roadway itself and the prevailing traffic conditions than by the posted speed limit.

California’s basic Speed law requires that:

“No person shall drive a vehicle upon a highway at a speed greater than is responsible or prudent having due regard for the weather, visibility, the traffic on, and the surface and width of the highway, and in no event at a speed which endangers the safety of persons or property.”

Speed limits are called prima facie limits, which “on the face of it” are safe prudent under normal conditions. Certain prima facie limits are established by law and include the 25-MPH limit in business districts and residential neighborhoods, the 15-MPH limit in alleys, at blind intersections and blind railroad crossings and a part time 25-MPH limit in school zones when children are going to and from school. These speeds are not always posted but all California motorists are required to know the basic 15 and 25 per hour speed laws.

Local Authorities on the basis of traffic engineering surveys may establish speed limits. These surveys include and analysis of roadway conditions, accident records, and the prevailing speed of prudent drivers. If speed limit signs are posted for a lower limit than is need to safety meet these conditions, may drivers will simply ignore the signs. At the same time, other drivers will stay within the posted limits. This generally increases conflicts between faster and slower drivers, reduces gaps in traffic which could safety be used and increases the difficulty for pedestrians to judge the speed of approaching vehicles. Studies have shown that where uniformity of speed is not maintained, accidents generally increase.