Northern Virginia Smart Traffic Center (Virginia)

The Northern Virginia Smart Traffic Center is a high-tech communications hub situated at the crest of a hill above the Pentagon. Controllers in this Traffic Center oversee more than 100 miles of roads. Computer monitors and cameras are situated so that controllers can tell what is happening on these roadways at any given time.

In addition to the usual congestion mitigation, incident management and traffic planning efforts, the Northern Virginia Traffic Operations Center is also an integral component in the best use of busy HOV lanes.

Man at STC StationGates and gate groups are used to reverse HOV lanes to accommodate the traffic flow heading north and east in the morning and south and west in the afternoon. Traffic is also controlled via ramp meters that limit traffic flow onto the mainlines through the use of traffic signals at the bottom of entrance ramps.

Loop detectors and pavement sensors that are embedded in the roadways prompt an automatic incident detection system that alert Operations Center controllers when and where there is likely to be an accident. This equipment also gathers speed volume and occupancy data.

The Operations Center even uses a meteorological weather satellite to monitor rain, snow and ice conditions.

The Northern Virginia Traffic Operations Center Operators have more than 5,000 pieces of equipment in the field to help them do their job including:


 * 109 cameras
 * 222 variable message signs
 * [24 gates on I-66 HOV lanes for use during peak travel hours
 * 21 gate groups on I-95/I-395 for reversible HOV lanes
 * 25 ramp meters for inside the beltway on I-66 and I-395
 * 30 lane control signals
 * 23 vehicle classification stations
 * 177 controllers with sensors and loop detectors

To alert the public of traffic conditions, the Smart Traffic Center uses variable message signs and Highway Advisory Radio sites. Commuters and travelers can tune to AM 1620 when they are within a five- to seven-mile radius of the radio sites including two new sites—one specifically for the Springfield Interchange and one for the Woodrow Wilson Bridge. The Smart Traffic Center also provides traffic and road condition information to the Emergency Operations Center in Richmond. Travelers can call the Highway Helpline at 1-800-367-ROAD for real-time traffic information, or they can check the road conditions map on VDOT's Web site. (reference: http://ddot.dc.gov/ddot/frames.asp?doc=/ddot/lib/ddot/information/emergency/7_Command-Control.pdf)