Northwest Corridor Express Lanes

Original plans

The Georgia Department of Transportation (GDOT) and Georgia Regional Transportation Authority began working on the Northwest Corridor HOV/BRT project in 2004. In the initial plan, the new lanes would be shared between bus rapid transit and high occupancy vehicles. Bus stations and HOV-only exits would be built at roads which currently cross the highways, but have no access to it.^[3] New lanes would be divided from the regular ones by concrete barriers, not just by white double-stripes as was done by GDOT inside the Perimeter.

There were also plans to add two truck-only lanes in each direction, further expanding the highway by another six lanes (including emergency lanes). Separating traffic was proposed because it would smooth traffic and make the main lanes safer for cars. However, this portion of the project was contested by the trucking industry, who argued that trucks avoiding the tolls on I-75 would increase congestion on the adjacent Cobb Parkway.^[4]

Plans scaled back

Citing the enormous cost of the plan (around $4 billion),^[5] in 2009 it was scaled back to putting two barrier-separated reversible lanes on I-75 to I-575, and one in the median on each road north of there. There would no longer be HOV exits on I-575, just slip roads connecting with existing lanes allowing access to regular exits. It was not stated how much land would be taken on the southern portion. There was already a provision for a future HOV exit in the median at the Terrell Mill Road underpass, however the remainder has no median, only a wide left shoulder and a concrete barrier. It was also left unknown how the lanes would tie into the interchange at I-285.

Construction on the project began in September 2014.^[6]

Completion

The project was completed and opened to traffic on September 8, 2018. The Cobb County bus system (CobbLinc) and the state-funded commuter bus system (GRTA Xpress) shifted the bus routes on I-75 or I-575 to use the express toll lanes.^[7] When the lanes were opened to the public on September 8 they were toll-free for a two-week trial period; however, all who used the lanes during that time were still required to have a Peach Pass to access it.^[8] Unlike the northeast express lanes on I-85 in Gwinnett, the northwest lanes charge a toll for high-occupancy vehicles and alternative-fuel vehicles. In 2018, the trade publication Roads & Bridges named the Northwest Corridor Express Lanes the number one road project of 2018 in the United States.^[9]