We receive many resident requests for the installation (and sometimes removal) of signs and markings. The most common requests are for stop signs and red curbs. Each request is analyzed to see if an installation or removal is necessary. Depending on the complexity of the request this could take a few days to a few weeks (or longer if it is something that has to go to City Council for approval). The length of time is usually dependent on the amount of data that must be collected before a decision can be made. Once a decision is made to install or remove a sign or marking a work order is issued to our Streets Department for the work to be performed.
The Federal "Manual on Uniform Traffic Control Devices" (MUTCD) issued by the FHWA dictates the location, size, shape and color of all traffic signs and markings. This manual has guidelines for installing signs and thus creates uniformity from state to state. The State of California has a Supplement to the MUTCD with additional requirements. The City of Pleasanton is required by State law to comply with the guidelines of the MUTCD and California Supplement.
Stop signs are installed at an intersection only after a careful engineering evaluation of the existing conditions indicates that their installation is appropriate, and that there is a need for stop signs in order to provide access or assign right of way. The MUTCD and California Supplement identify specific traffic and pedestrian volumes, accident history and unusual conditions that would indicate need for installation of stop signs.
Overuse of stop signs reduces their effectiveness if installed where not justified.
Each year, the City receives many inquiries about installing stop signs as a way to reduce speeding. However, research shows that other measures are more effective than adding stop signs. The purpose of stop signs is to assign right-of-way at an intersection, not to control speed. Some of the reasons why stop signs are not a good speed control tool include:
- Drivers are forced to come to a complete stop, even if they are going the speed limit
- Potential increase in rear end collisions
- Drivers tend to increase speeds between stops
- Increased noise due to hard starts and stops
- Increase in air pollution
Citizens frequently ask why we don't install lower speed limit signs to control speed.
Speed limits in non-residential areas are established based on the speed of the vehicles on the roadway. Most drivers drive at a speed that they consider comfortable, regardless of the posted speed limit. "Before and after" studies have shown that there are no significant changes in average vehicle speeds following the posting of new or revised speed limits. Furthermore, research has found no direct relationship between posted speed limits and collision frequency.
All fifty states base their speed regulations on the Basic speed Law: The California Vehicle Code states "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 65 mph. Certain speed limits are established by State law and include the 25 MPH speed limit in business and residential districts and 25 MPH in school zones when children are present. These speed limits do not need to be posted in order to be enforced.
Speed limits between 25 and 65 MPH are established on the basis of engineering and traffic surveys.
Engineering and traffic surveys include an analysis of roadway conditions, collision records and a sampling of the prevailing speed of traffic. A safe and reasonable limit is set at the 5 mile per hour increment closest to the 85th percentile speed of motorists.
A 5 mile per hour speed limit reduction is allowed at locations with unusual conditions not readily apparent to the driver.
Speed limits provide notice to drivers of the maximum speed limit on a roadway and are an enforcement tool to assist police in separating violators from the reasonable majority.
If posted speed limits are set artificially low, disrespect is created for the limits, and since they are not set in accordance with the law, they are not enforceable with radar. The state maximum speed limit would then apply. The occasional driver attempting to obey the posted speed limit may decrease safety by causing additional lane changes, passing and tailgating.
Setting speed limits near the prevailing speed of traffic results in traffic flowing at uniform speeds. Correctly set speed limits can increase safety and lead to fewer accidents.