Speed limits are often taken for granted and, until a problem arises,
most people pay little attention to them. The following information
will help you understand how speed limits are established, and what they
can and cannot do.
All 50 states base their speed regulations on the Basic Speed Law:
"No person shall drive a vehicle . . . at a speed
greater than is reasonable or prudent . . . and in no event at a speed
which endangers the safety of persons or property."
Under California law, the maximum speed limit in urban areas is 55
mph. All other speed limits are called prima facie limits, which are
considered by law to be safe and prudent under normal conditions. Prima
facie limits established by State law are as follows:
- 55 mph is the maximum speed limit in urban areas
- 25 mph is the speed limit in business/residential districts and
school zones (with children present)
- 15 mph is the speed limit in alleys, railroad crossings, and
intersections - where visibility is limited
How are speed limits determined between 25 and 55 mph?
Speed limits are established on a basis of traffic engineering
surveys. These surveys include an analysis of roadway conditions,
accident records, a sampling of the prevailing speed of traffic, amount
of side traffic access, and traffic volumes.
Generally speaking, a safe and reasonable limit is set at or below
the speed at which 85% of the drivers drive. Posting an appropriate
speed limit simplifies the job of enforcement officers, since most of
the traffic is voluntarily moving at the posted speed. Blatant speeders
are easily spotted, safe drivers are not penalized, and patrol officers
aren't expected to enforce unrealistic and arbitrary speed limits.
How can I get a speed limit sign placed on my street to slow
traffic?
The most common misconception about speed limits is that putting up a
sign will slow the speed of traffic, reduce accidents, and increase
safety.
The truth is, most drivers drive at a speed that they consider to be
comfortable and safe, regardless of the posted speed limit. The County
of Shasta does not usually install signs on most residential streets,
but instead relies on the California Vehicle Code 25 MPH limit. Studies
have shown that there are no significant changes in average vehicle
speeds following the posting of new or revised speed limit signs.
Furthermore, there is no direct relationship found between posted speed
limits and accident frequency.
However, there are ways to slow down drivers on your street:
Increased Enforcement: This requires an officer to
ticket those drivers driving at excessive speeds.
Speed Monitoring Awareness Radar Tool (Smart Trailer):
Access to a radar device, mounted on a small trailer, is available to
clock vehicles and exhibit their speed on an oversized display board.
The device has helped control chronic speeding problems by letting
motorists know when they are exceeding the limit. This device is set up
by the Sheriff's Department upon request and availability.