August 26, 2021

MDOT SHA Set to Begin Ramp Metering on Southbound I-270

In an effort to relieve congestion on I-270, the Maryland Department of Transportation has installed a ramp metering system. Ramp metering uses sensors that detect real-time traffic conditions and activates traffic signals to more efficiently control traffic merging onto the highway to minimize delays and reduce congestion.

On Aug. 17, crews uncovered and turned on signals to flashing yellow along the 23 southbound locations. The flashing lights will alert motorists that activation of the ramp metering system is coming. The turn-on process will take about a week to complete, with groups of ramp signals being activated each day. Then, on or about Sept. 15, crews will turn on the ramp metering system at all southbound ramps where the equipment is installed.

When ramp metering is in operation:
  • Motorists will see a warning sign with flashing beacons.
  • When the beacons are activated, motorists should be prepared to stop at the stop line.
  • Once the signal turns green, drivers may proceed on the ramp and merge onto the highway.
  • The signal will allow one car at a time to enter the highway, optimizing traffic flow onto I-270.
  • Motorists are advised to use caution and reduce speeds approaching the traffic signal as there may be stopped vehicles waiting to merge onto the highway.
Ramp metering signals will have the capability to operate between 4 a.m. and 11 p.m. daily and are anticipated to be active during peak-traffic hours and when sensors detect congestion on I-270. The system also detects the length of vehicles in queue to help ensure ramps don’t back up onto arterial roadways. For more information and to view a location map and ramp metering video, click here.