The Winston-Salem Department of Transportation (WSDOT) installs and maintains all traffic signals within the city in accordance with the Manual on Uniform Traffic Control Devices. Signals are installed based on need as determined by traffic engineering studies. The Director of Transportation approves the installation of all signals. The North Carolina Department of Transportation (NCDOT) must also approve signal installation on a State System street.
Computerized traffic control coordinates the timing and operation of over 300 traffic signals citywide. Drivers can travel from one signal to the next with minimum stops and delays. Metal detectors embedded in the pavement sense vehicles waiting in travel lanes. The signal coordination reduces driver delays, vehicle pollution emissions, and gasoline consumption. Timing plans are evaluated every six months and specific locations are evaluated based on citizen concerns and complaints.
To report non-functioning or improperly functioning signals, please call City Link at 311 or 336-727-8000.
While there are many types of traffic signals located throughout Winston-Salem and Forsyth County, here are a few typical situations:
No left turn signal The driver makes a left turn after checking to see that there is no oncoming, conflicting traffic. There are a minimum of two signals showing no arrows at all. If a bulb burns out, a second signal will provide direction.
Protected Left Turn The driver will have a protected opportunity to make a left turn. There are two possible situations:
Most signals over left turn lanes have two red bulbs. If one red bulb burns out, the second bulb will continue to provide direction. There will always be a sign stating "Left Turn Signal" at this type of signal.
New red lights that will never entirely burn out have recently become available. These lights use LED (light-emitting diode) technology, and indicate a red arrow when left turns are not permitted. Because the red arrows will never burn out completely, a second red bulb is unnecessary. The yellow and green lights on these signals use regular bulbs, which may burn out. However, these signal indications are not as critical as the red indications. The through lane will have two standard signals in case one bulb burns out.
Permissive Left Turn If a green arrow disappears and a green "ball" remains, the driver is permitted to make a left turn after yielding to conflicting traffic.
Left Turns on One-Way Streets It is against North Carolina law to turn left on red from a one-way street onto another one-way street, even if there is no conflicting traffic. In all cases, if there is no signal indication, the driver should stop, check and wait for conflicting traffic, and proceed safely.
Right Turn Signal or Sign Drivers turning right may see a "Right Turn Signal" sign in front of the right turn lane. This means that there will be a protected opportunity to make a right turn; the driver may still turn right on red after coming to a full stop and waiting for any conflicting traffic to pass unless there is a sign saying "No Turn on Red."
There are nationally applied standards, or "warrants," for determining whether a traffic signal should be installed. If one or more of the following 9 warrants is met, a signal may be installed after an engineering study of traffic conditions, pedestrian use, and physical characteristics of the location has been done. The results of the study must show that the signal will improve the overall safety and operation of the intersection.
Eight-hour vehicular volume/minimum volume If a certain number of cars use the main street and the side street for eight hours within a 24-hour period, then a signal is justified. The number of cars needed varies with the number of lanes. For example, if the main street and the side street each have two lanes, there have to be 600 vehicles an hour using the main and 200 an hour using the side street.
Interruption of continuous flow There has to be so much traffic on the main street that there are no gaps in traffic to allow drivers from the side street to pull out. For the same two lane roadways above, the warrant sets traffic minimums of 900 vehicles an hour on the main street and 100 on the side street.
Four-hour-vehicular volume This allows a signal if there is very heavy volume on both the side and main streets for four hours a day. This is a sliding scale, where the more volume there is on the main street, the less volume is required on the side street to meet this warrant.
Peak-hour volume This one allows a signal if there are high volumes of traffic for one hour a day. This is a formula that can justify a signal if traffic on the side street is held up a certain amount of time.
Pedestrian volume If there is a sufficient amount of pedestrian traffic crossing the main road, a signal can be installed. There must be 100 pedestrians an hour in any four hour period in a day or 190 pedestrians in a one hour period.
School crossing This is pretty flexible. If gaps in traffic are not adequate for groups of students to cross, a signal can be put installed.
Coordinated signal system A signal can be used to keep traffic grouped together. A signal can be added to a network of signals, if it is expected to make the system work better. It is not used locally to justify signals
Accident experience If trial alternatives and enforcement fails to reduce crashes and there are five or more accidents over 12 months that can be remedied by a signal, and the vehicle counts are 80% of those used in 1, 2 and 3.
Roadway Network Installing a traffic control signal at some intersections might be justified to encourage concentration and organization of traffic flow on a roadway network.
If you would like to request a new traffic signal, you can contact the Winston-Salem Department of Transportation by emailing City Link.