Your commute on Ga. 400 is about to get worse. Then it’ll get better (maybe).

Completing the Ga. 400 express lanes, expected in early 2031, will get the Georgia Department of Transportation closer to its goal of an uninterrupted network of toll lanes throughout metro Atlanta. A similar public-private approach is how GDOT plans to build 40 miles of toll lanes on the top half of I-285, one of the next projects on its to-do list.

Unlike existing express lanes on I-85 and I-75, these toll lanes will be managed by a private company, SR 400 Peach Partners. In exchange for 50 years of toll revenue, the company, an international conglomerate of construction, engineering and financing partners, paid a $3.8 billion concession payment and will fund construction and maintenance along the route for the length of the contract.

Georgia is fronting just $120 million toward the total project costs, including $100 million in general obligation bonds to pay for the dedicated bus lanes MARTA will use for a new rapid bus route.

GDOT will retain oversight of the highway, and the contract with Peach Partners sets an upper limit on tolls and requires the company to guarantee certain speeds in the express lanes.

In an interview, McMurry said the public-private partnership eliminates a common complaint about the use of taxpayer dollars to build toll lanes. Those who use the express lanes will be the ones paying, to the benefit of other drivers who should experience less congestion in general lanes.

Credit: Arvin Temkar/AJC

Credit: Arvin Temkar/AJC

But exactly how much of a traffic reduction is still to be seen.

When GDOT opened the Northwest Corridor express lanes in 2018, the average speed on I-75 northbound during the afternoon rush hour was twice what it was before the express lanes opened.

In the first two years of the Ga. 400 toll operations, the state expects to see a 10% reduction in the time drivers in the general lanes spend in traffic, said Jannine Miller, who oversees the State Road and Tollway Authority. Crashes, which are both dangerous and can snarl traffic, are projected to drop by 8%.

Typically, new road lanes reduce traffic times temporarily before congestion climbs back up. The I-85 express lane near Pleasantdale Road, which opened in 2011, runs faster than the general-purpose lane next to it, but only barely, according to an analysis of the last 30 days of traffic data by The Atlanta Journal-Constitution.

In the meantime, traffic on Ga. 400 is likely to get worse before it gets better thanks to construction.

“The coming years are not going to be easy in terms of the construction disruption,” said Nicolas Rubio, a CEO of Meridiam North America, which is part of Peach Partners. “We will do our best to manage that in a way that the community can continue traveling along the corridor.”

In preparation for construction, crews began clearing trees along Ga. 400 last year. The express lane construction is split into three segments, and work on the southern portion of the route is expected to start first.

Credit: Natrice Miller

Credit: Natrice Miller

In the southernmost segment, work has already started between Abernathy Road and Roberts Drive. Drivers can expect to see work taking place southbound between Abernathy Drive and Spalding Drive and northbound between Northridge Road and Roberts Drive.

Further north, the first work will start this summer near the Holcomb Bridge Road interchange.

At the top of the route, work will begin in May with tree clearing and grading operations on the northbound lanes between McGinnis Ferry Road and McFarland Parkway.

In addition to building out new express lanes in either direction, the project also involves repaving the existing surface.

The short-term construction pains will be worth the gains in the long run, officials said.

Brandon Beach, who represented Alpharetta in the Georgia Senate and who now serves as U.S. treasurer, came home for the groundbreaking and predicted the project would transform the northern suburbs.

Credit: Arvin Temkar/AJC

Credit: Arvin Temkar/AJC

“I’m a firm believer that there’s a direct correlation between infrastructure investment and jobs and economic development, and that’s what we’ve done here,” Beach said in an interview.

Beach said the public-private partnership model, which GDOT developed while he served on the state transportation board, is a smart way forward to meet the region’s needs as the population continues to grow.

“We’ve got to prepare for it and have the infrastructure in place,” he said.

Credit: Arvin Temkar/AJC

Credit: Arvin Temkar/AJC

Sean McMaster, the head of the Federal Highway Administration, said Georgia is setting an example for what President Donald Trump’s administration wants other states to do: find innovative solutions to traffic.

U.S. Transportation Secretary Sean Duffy sent a memo to governors this week asking them to identify congestion chokeholds and their plans to fix them. Projects like the Ga. 400 one are exactly the type that federal officials want to see, McMaster said.

Traffic is “a hidden tax on our economy and on our drivers,” McMaster said, adding that addressing it is one of the administration’s top priorities.

“We’re excited to find other opportunities to leverage those scarce federal resources to allow for private sector investment to really expand the scale and scope of what we can do around the country,” he said.

Senior editor Charles Minshew contributed to this report.