I-66 highway uses smart shoulder to move traffic

Automatic Incident Detection helps smooth the process

“The Citilog Automatic Incident Detection system made it easier to open the shoulder on demand which has been increasingly needed to face the increase of traffic.” Mr. Kamal Suliman, ITS Manager, Virginia Department of Transportation.


Since I-66 is the only Interstate Highway running west from Washington, D.C., into Northern Virginia, traffic on the road is often extremely heavy. In order to improve traffic flow, the Virginia Department of Transportation has implemented a number of initiatives such as HOV (high occupancy vehicle) lanes and allowing vehicles to drive on the shoulder at set times during morning and evening rush hours. With the continuous increase of traffic, VDOT has been looking for solutions to open the shoulder to traffic dynamically, i.e. depending on actual traffic conditions.


VDOT installed dynamic message signs on gantries along I-66 using a red cross or a green arrow to indicate whether the shoulder is open to traffic or not. VDOT also deployed Citilog’s video-based Automatic Incident Detection (AID) system to monitor the shoulders. The AID system uses video streams from fixed traffic cameras in order to identify incidents and accidents. The system then alerts operators in real time. The shoulder is now opened for travel by the operators when the speed drops, indicating that traffic is congested, and closed again when traffic lightens up.


Citilog’s AID systems detect incidents and accidents more effectively, thus ensuring that those incidents are cleared faster and traffic is returned to normal as quickly as possible. The system also made it easier to open the shoulder on demand by monitoring the shoulder 24/7 for stopped vehicles and making sure the shoulder is available when it needs to be opened.

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