June 16, 2021

MDOT SHA to Begin Testing of New Ramp Metering System on I-270 As Part of Plan to Manage Congestion

The Maryland Department of Transportation State Highway Administration (MDOT SHA) expects on Wednesday, June 23, to activate and test a new ramp metering system on the ramp from northbound MD 118 to southbound I-270 in the Germantown area. This will be the first location activated in the new ramp metering system that will eventually include 22 northbound and 23 southbound I-270 ramps.

This single location was activated as a flashing yellow signal on Wednesday, June 16. It will become fully operational on June 23. MDOT SHA is testing the system for one week and will then deactivate it until the entire southbound I-270 ramp metering system is activated later this year.

The northbound I-270 ramp metering system is expected to be activated in 2022.

Ramp metering is a part of the I-270 Innovative Congestion Management (ICM) project designed to help reduce congestion on this busy interstate. The system uses sensors that detect real-time traffic conditions and activate traffic signals, when needed, to more efficiently control how traffic merges onto I-270. This will allow motorists to merge safely onto I-270 while minimizing delay and reducing congestion.

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 go from each lane, optimizing traffic flow onto I-270.
The 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 congestion is present on I-270.

For more information and to view a map and ramp metering visualization video, click HERE.


The I-270 ramp metering system will be the first program of its kind in Maryland, but similar ramp meter programs have been used elsewhere and MDOT SHA said that they have been proven to be cost-effective tools to help address congestion and safety by regulating traffic flow onto the highway.

Ramp metering is one element of the I-270 ICM Project that Maryland Governor Larry Hogan announced in 2016 to provide congestion and improve travel times throughout the 34.4-mile I-270 corridor from I-70 in Frederick to the point where the highway meets I-495 in Bethesda. Other elements in the Governor’s proposal include additional auxiliary lanes between interchanges; extension of acceleration and deceleration lanes and reconfiguration and restriping of existing lanes to optimize traffic operations.

Montgomery County Executive Marc Elrich has stated his opposition to significant parts of the Governor’s overall proposal.

For a list of all major MDOT SHA projects, go to Project Portal.