I-85 in Atlanta reopened months ago. But the repercussions of the spectacular bridge collapse continue.

The opening of another highway project – the Northwest Corridor Express Lanes in Cobb and Cherokee counties – may be pushed back for up to six weeks because of delays caused by the I-85 bridge collapse, according to the Georgia Department of Transportation.

The new express lanes are scheduled to open next summer. But construction at a key interchange – I-75 and I-285 in Cobb County – was suspended for six weeks last spring to accommodate heavier-than-usual traffic caused by the I-85 collapse, Joe Carpenter, GDOT’s director of public-private partnerships, told The Atlanta Journal-Constitution.

The I-85 bridge collapse closed one of the main highways into the heart of Atlanta for six weeks, forcing hundreds of thousands of commuters to find alternative ways to work. The highway reopened six weeks later , ahead of schedule. A homeless man has been charged with setting the blaze that destroyed the highway.

To keep traffic moving during the crisis, GDOT suspended construction at the I-75/I-285 interchange. Carpenter said contractor Northwest Express Roadbuilders has already made up some of lost time on the $834 million express lane project. He does not expect the full six weeks will be lost.

The Northwest Corridor project will add 30 miles of reversible lanes on I-75 and I-575. It's part of a massive network of toll lanes that will eventually include I-85 northeast of Atlanta, I-75 south of the city, the top half of the Perimeter and Ga. 400.

Carpenter said construction on the Northwest Corridor lanes is 85 percent complete. But don't expect to drive on any portion of them until the project wraps up next summer. Like the I-75 South Metro Express Lanes, they will be reversible lanes closed off from the general purpose lanes, and Carpenter said the entire system of lanes must be finished before they can open to traffic.