Traffic Signals

Traffic Management Center

Arlington’s Traffic Management Center (TMC) is a state-of-the-art control center that supports critical operations throughout the County by optimizing our street light, traffic signal and traffic camera networks to improve transit operations and provide real-time monitoring.

Features include:

  • A mainframe computer that supports street lights and the signals system for real-time conditions.
  • Management of the smart street light system, which will save as much as 80 percent in energy costs.
  • Management of evacuation routes during emergency situations.
  • Ability to update variable message signs with real-time traffic information and incident management updates via Bluetooth technology.
  • Detection and monitoring of pedestrian and bike traffic in 3-D.
  • Ability to monitor transit operations in real time.

The Traffic Management Center is supported by a 45-mile fiber optic network system throughout the County. Learn more about the Fiber Optic Network Project.

LED traffic signals in Rosslyn.

We began converting traffic signals to light-emitting diode (LED) technology in the mid-2000s. These LEDs modernize the network, reduce overall costs and minimize the environmental impact.

Traffic Signals

Traffic signals provide orderly movement of traffic by assigning rights of way at intersecting streets. They’re usually very effective, but can be inefficient and potentially dangerous to motorists and pedestrians when installed under inappropriate conditions. Signals that are installed when no legitimate need exists often generate an increase in vehicle stops, traffic delays, fuel consumption, traffic accidents and disrespect for other traffic signals.

Installation of traffic signals is preceded by a thorough engineering study. The U.S. Department of Transportation Federal Highway Administration has published the Manual on Uniform Traffic Control Devices, which contains the standard guidelines for all traffic signals in the United States, including Arlington.

Adaptive Real-Time Responsive Traffic Signal System

The traffic signal system is configured to improve traffic flow and reduce vehicle emissions by continuous monitoring and optimizing of traffic signal operations based on real-time traffic conditions. The system manages traffic flow in Ballston and Pentagon City, and along Arlington Boulevard (U.S. Route 50), Columbia Pike and Lee Highway (U.S. Route 29). Additionally, the system supports emergency evacuation and special event situations. All traffic signals have a backup power supply in the case of power failure.

Traffic Cameras

Closed-circuit televisions (CCTVs), or traffic cameras, are used throughout the County to detect congestion and notice accidents. There are currently 150 CCTVs located at critical intersections. This number will increase to more than 200 CCTVs during the final phase of the Fiber Optic Network Project.

HAWK Beacons 

A HAWK Beacon (High-intensity Activated CrossWalK) is a device that assists pedestrians and bicyclists safely across busy streets. While different in appearance to the driver, to the pedestrian or bicyclist HAWKs work the same as button-activated traffic signals. It stops traffic with a red light allowing pedestrians and bicyclists to cross safely. At rest, HAWKs remain dark. HAWKs can be triggered automatically or manually with a push button. It will then go through a series of yellow and red sequences requiring motorists to slow down and stop. After pedestrians and  bicyclists cross, the HAWK will go dark again, allowing motorists to continue through the intersection.

Interactive Audible ADA Accessible Pedestrian Signals

Audible pedestrian signals are installed as the standard at all new traffic intersections in Arlington. Requests for audible pedestrian signals to be added to an already existing intersection can only be made by the visually impaired person who will be using the signal and will require a meeting with County staff at the location of the signal to determine the specific requirements and available right of way. Requests for audible pedestrian signals should be made to the Customer Call Center at 703-228-6570. 

VMS on Arlington Boulevard.

A variable message sign on Arlington Boulevard.

Variable Message Signs (VMS)

As part of the Fiber Optic Network Project and the intelligent transportation system, eight VMS are located on Arlington Boulevard (4), Columbia Pike (2) and Lee Highway (2). The first two signs (installed on Arlington Boulevard near the Washington Boulevard interchange) display traffic alerts, such as “congestion ahead.” The other six signs use media access control identification technology to communicate real-time travel information to motorists estimating travel time from the sign location to the County line. These VMS will also be used for incident management and the Amber Alert system.