RICHMOND, Va. (WNCN) – LED signs that will display changing speed limits will soon be fully activated on a stretch of Interstate-95 northbound in Virginia.

The Virginia Department of Transportation said the variable speed limit signs will replace static speed limit signs for 15 miles in Caroline and Spotsylvania counties and in the City of Fredericksburg.

The new signs, 48 in total, are placed every half-mile to one mile in the project corridor.

The signs were illuminated last week but will be fully activated on Wednesday to display variable speed limits between 35 and 70 mph.

VDOT said speed limits will change based on real-time conditions:

Vehicle detectors installed along I-95 use radar to collect traffic speed and volume data, which is fed into a software program.

The program uses an algorithm to recognize when speed limits should be lowered, such as when traffic volumes are heavy and speeds are high.

The program then assigns incrementally lower speeds to harmonize traffic flow and reduce the risk of crashes and congestion.

“Drivers will be expected to adjust their speed in this area based on information about real-time traffic conditions and delays on the road ahead. Gradually slowing traffic as it approaches congestion will help to reduce the risk of crashes, and stop-and-go backups,” VDOT said in a release.

Flashing lights on the signs will be illuminated when speed limits are reduced below the maximum limit.

“When we studied the I-95 corridor to identify areas for operational improvements, we found recurring congestion was contributing to crashes and driver delay at this location, especially on weekends and during holidays,” said Mena Lockwood, P.E., assistant state traffic engineer for the Virginia Department of Transportation.

Message boards along the interstate will say why speed limits are being changed — congestion ahead, weather conditions or lane closures.

VDOT also said variable speed limits posted on the LED signs are enforceable, just as with any other posted speed limit sign.

Furthermore, variable speed limit signs have been in use on Interstate-77 at Fancy Gap and on the approaches and in the Hampton Roads Bridge-Tunnel, as well as on the Monitor-Merrimac Memorial Bridge-Tunnel.