New collector-distributor lane opened on I-285 near GA 400

I-285 sign

This project from the Georgia Department of Transportation did not take place in Cobb County, but since it affects the connectivity between I-285 West and Georgia 400 it will definitely have an effect on traffic patterns in northeastern Cobb County and the Cumberland area.

A press release from the GDOT announced that contractors have completed a new collector-distributor (CD) lane from Peachtree Dunwoody Road to Roswell Road, and advanced two new ramps.

For further details read the press release reprinted below:

As part of the Transform 285/400 project, Georgia Department of Transportation (Georgia DOT) construction partners completed a new collector-distributor (CD) lane from Peachtree Dunwoody Road to Roswell Road, and advanced two new ramps – the second phase of a ramp for motorists transitioning from SR 400 southbound to I-285 westbound, and a modified exit ramp from I-285 westbound to Roswell Road.

“We’re pleased to see the completion of three major milestones at once,” Georgia DOT P3 Project Manager Marlo Clowers, P.E., DBIA said. “As we always have, we ask the public to pay close attention to the changes in the roadway, be mindful of the work and the workers in the area, and please proceed with caution.”

The new CD lane doubles as the exit ramp for drivers on I-285 westbound traveling to Roswell Road (Exit 25). Drivers will now exit onto the CD lane between Peachtree Dunwoody Road and SR 400, almost 1 mile before the previous exit ramp’s access point. Drivers who miss the new exit must proceed to Riverside Drive (Exit 24) for return access to Roswell Road from I-285 eastbound. 

Motorists using the new SR 400 southbound ramp to I-285 westbound will travel the new CD lane briefly before merging with traffic from I-285 westbound ramp using a new slip ramp. Motorists entering I-285 westbound from Glenridge Drive will no longer have access to Roswell Road. 

Motorists at the Roswell Road interchange will notice minor changes in the exit ramp’s configuration from the shift onto the new pavement. The ramp will still feature one left-turn lane and one right-turn lane onto Roswell Road from I-285 westbound while work progresses.

Opening these movements will allow crews to continue critical construction activity in the I-285/SR 400 Interchange, including a ramp extension along I-285 eastbound to Ashford Dunwoody Road (Exit 29) expected to open later this month. This opening will precede lane closures in both directions between Roswell Road and Ashford Dunwoody Road this fall to perform bridge construction over Peachtree Dunwoody Road, SR 400 and Glenridge Drive. 

When completed, the Transform 285/400 project will improve operational efficiency, save 12,500 hours per-day of driving time and prevent worsening traffic delays over time, and improve safety for those traveling through the I-285/SR 400 Interchange. 

Advanced signage and various message boards will assist motorists navigating the roadway and ramp configuration. Additional project information is available at