Frequently Asked Questions
- Will a traffic signal reduce crashes at our intersection>
- Traffic signals don't always prevent collisions. Typically, when a signal is installed, the total number of
crashes increases, but the severity decreases. Where signals are used, the most common result is a
reduction in right-angle collisions, however, rear-end crashes are prone to show an increase. Signals also may give pedestrians a false sense of security.
- When are traffic signals installed?
Traffic signals are intended to facilitate the orderly movement of traffic. As the most restrictive form of
traffic control, traffic signals are installed only where less restrictive signs or markings do not provide a
sufficient level of control. Most intersections would not necessarily be improved or made safer by the
installation of a traffic signal.
Unnecessary signals cause wasteful and annoying delays to the flow of traffic. They can increase
traffic on the side streets as drivers seek alternative routes through neighborhoods. Excessive starting
and stopping burns needless amounts of gasoline, resulting in pollution and economic loss. And as
previously mentioned, they can increase the total amount of crashes at an intersection.
- What are the official guidelines?
- The Columbus Consolidated Government follows City policies and Georgia State Law, which requires
us to follow the national guidelines outlined in the
Manual on Uniform Traffic Control Devices
. Traffic control devices include signal lights, traffic signs and markings. The MUTCD covers
all aspects on the placement, construction and maintenance of every form of approved traffic control.
- What are the installation criteria for traffic signals?
In determining the need for signalization, traffic engineers ask several standard questions about the
- Is the volume of traffic at the intersection such that a signal is needed to decrease congestion
- Will the installation of a signal allow for continuous, uniform traffic flow with a minimum
number of vehicle stops?
- Do a significant number of drivers on the side streets experience excessive delay in
attempting to cross or enter the major streets?
- Does the intersection have a high number of pedestrians whose crossing can be made safer?
- Does the number of school children crossing at the intersection warrant special protection? If so, would a signal be the best solution?
- Will probability of occurrence in the number and type of reported collisions be significantly reduced by a signal?
In order to answer these questions, a traffic study by a qualified and experienced traffic engineer is required of the intersection. As part of the study, traffic volume levels and crash history are compared with established national standards for signalization. Intersections which conform to these standards or warrants are the best candidates for signalization.
Installation of a traffic signal typically costs between $60,000 and $120,000 per location. Factors that contribute to this cost include highly specialized control equipment and hardware that is needed, plus the extent of the system installed underground.
If you have any questions about Traffic Signals, please contact the Columbus Consolidated Government, Traffic Engineering at 706-653-4135