Giant toll lane project ramps up — and up — on I-75 and I-575 in Cobb and Cherokee

30 miles of reversible lanes, with 39 new bridges
The full 30-mile project is expected to cost $834 million. BOB ANDRES / BANDRES@AJC.COM

Credit: Bob Andres

Credit: Bob Andres

The full 30-mile project is expected to cost $834 million. BOB ANDRES / BANDRES@AJC.COM

Toll lane projects in the pipeline

• I-85 Express Lanes extension: 10 miles of new lanes from Old Peachtree Road to Hamilton Mill Road. The project is scheduled for groundbreaking next spring, and an opening in June 2018. Cost: About $140 million.

• I-75 South Metro Express Lanes: 12 miles of two new barrier-separated, reversible lanes within the I-75 median from McDonough Road to Stockbridge Highway. Construction is underway, with the lanes are projected to open in winter 2017. Cost: $221 million.

• Northwest Corridor: 30 miles of new lanes along I-75 from Akers Mill Road to Hickory Grove Road and along I-575 from I-75 to Sixes Road. Construction is ongoing, with opening in spring or summer 2018. Cost: $834 million


November 2004 – The Northwest Corridor is proposed as a $1.8 billion project by a consortium of private builders. Their original concept includes truck-only lanes and also accommodates a bus-rapid transit service made up of linked, rubber-tired passenger vehicles with wide doors and platform loading — a cross between a MARTA train and an express bus.

2005 — Georgia signs a contract with the private consortium to build the Northwest Corridor.

2009 – The state, facing a budget pinch, decides not to proceed with the project as conceived. It included plans to add eight single-direction toll lanes on I-75, four for trucks and four for cars, and would have bumped cost estimates from $1.8 billion to $4 billion. Instead, planners adopt a reversible-lane concept. The number of toll lanes is scaled down to two on I-75 from I-285 to I-575, and one on I-75 and I-575 up to Hickory Grove Road and Sixes Road. The state dumps its privately funded toll partnership.

2011 — GDOT revises the project and puts it out to bid as a public-private project. The bid is later canceled.

2012 — The project is put out to bid for the third time.

2013 — Northwest Express Roadbuilders — a joint venture between Archer Western Contractors, headquartered in Atlanta, and Hubbard Construction Company of Winter Park, Fla. —- is named as the best of three bidders to design and build the toll lanes.

Sept. 17, 2014 — Groundbreaking ceremony for the Northwest Corridor.

2018 — Expected opening of toll lanes.

How will I pay?

The toll lanes will be part of the Peach Pass system already in place for the I-85 HOT lanes. Drivers can sign up for a Peach Pass online at or buy prepaid ones in stores. The transponder stickers are typically mounted to the windshield, where cameras read them automatically and drivers' accounts are billed as they travel in the lanes.

The toll will rise and fall depending on the amount of traffic in the lane to maintain speeds of 45 mph or greater.

Reversible lanes: what could go wrong?

The Northwest Corridor and the express lanes on I-75 in Henry and Clayton counties are both reversible lane systems. The direction of travel will go toward downtown Atlanta in the morning and away from it in the evenings to accommodate peak traffic demand. From Friday evening rush hour through Saturday, the lanes will continue to flow northbound. Overnight Saturday the lanes will switch to a southbound flow and remain that way through the Monday morning commute, so that there is just one directional shift over the weekend. Adjustments can be made if warranted or for special events like holidays or spring break.

To reverse the direction of flow, the state Department of Transportation will shut down the lanes for several hours during off-peak times at midday and overnight.

Electronic signs will inform motorists when the express lanes are open or closed well in advance of arriving at the entrance.

A system of gates will be employed to restrict or permit access based on the current direction and prevent wrong-way entry.

Prior to reopening the lanes, GDOT personnel will ensure they are clear by monitoring cameras along the route remotely from the Transportation Management Center. HERO trucks will also drive through the corridor to “flush” the system and confirm no vehicles or obstructions remain.

Northwest Corridor traffic relief?

The toll lanes are projected to attract 33,000 drivers per weekday in their opening year of 2018. By 2020, that number is expected to grow to nearly 40,000, and by 2030, more than 52,000. Some of those drivers would otherwise have been taking up space in the general purpose lanes. So their absence should free up traffic a little for all drivers. But that improvement in travel times for both general purpose and tolled lanes will also attract new drivers to I-75 and I-575. An analysis of traffic projections conducted by The Atlanta Journal-Constitution in 2013 found that drivers who paid the toll would see their commute times slashed by as much as two-thirds. Everyone else’s rush hour trip will remain about the same. Furthermore, several arterial roads in the vicinity of the highway will become more congested than they would have been if nothing was built, because of the increase in motorists trying to get to the interstate. These include South Marietta Parkway, Terrell Mill Road and Ga. 3 Connector/Roswell Road.

The next solution to Atlanta’s traffic is rising on massive columns of concrete and steel that march along Interstates 75 and 575 in Cobb and Cherokee counties.

The Northwest Corridor toll lane project is monumental in every way.

The project is remarkable not only for its 39 bridges: one of them, at 10 stories, is taller even than Spaghetti Junction, while another is 6,000 feet long; or its $834 million price tag; or the fact that this single endeavor is 30 miles long; or even for the slightly unsettling idea that the lanes will reverse direction twice per weekday: going inbound in the morning, shutting down near midday, flowing outbound in the evening.

Overriding all that is this: the Northwest Corridor express toll lanes represent the state’s primary strategy for fixing interstate traffic jams around metro Atlanta. The idea is simple: relieve congestion by billing the people who cause it.

By 2018, there will be more than 50 new miles of express toll lanes running through the median of I-75 south of metro Atlanta, towering above the west side of I-75 and I-575 northwest of the city, and adjacent to I-85 all the way up to the Hamilton Mill Road exit in Buford. Those are in addition t0 the 16 miles of High Occupancy Toll (HOT) lanes already operating on I-85 in Gwinnett County.

At the project’s groundbreaking, Gov. Nathan Deal called it “the most impactful and important project we’ve done here in decades.”

Metro toll-lane network envisioned

The Northwest Corridor project opens a new era in metro Atlanta’s decades-long battle with traffic: it’s huge, it’s expensive, and it’s just the beginning. Several years ago, state transportation officials decided that they would add no new lanes to metro Atlanta interstates unless the lanes were tolled.

By 2040 and perhaps far sooner, express toll lanes won’t be confined to portions of I-75 and I-85. You’ll find them along Ga. 400 and the top end of I-285, too. Eventually the plan is to connect all the major interstates around Atlanta with a seamless network of optional toll lanes.

The first step toward that toll network are the Northwest Corridor and the I-75 South Metro Express Lanes. The I-75 South Metro project is a smaller-scale, 12-mile tollway being built in the median of the interstate where it runs through Henry and Clayton counties.

The two projects are the first toll lanes to be built from scratch in metro Atlanta in more than two decades. They will differ significantly from the granddaddy of Georgia toll roads, Ga. 400, whose toll gates were torn down last year after the state ended the 50-cent toll.

This time, like the I-85 HOT lane, there will be no expirati0n date. These toll lanes are here to stay.

‘It’s all going to come together’

The idea for the Northwest Corridor has been around since at least 2004.

The I-75/I-575 corridor is one of the most congested in the state, carrying traffic between commercial centers at Town Center, Kennesaw State University, Marietta and Smyrna.

The project as currently conceived several earlier concepts fell through — has been in the works since 2012. Nevertheless, many people didn't realize that the Northwest Corridor was coming until the bulldozers arrived and shovels started turning earth.

The state Department of Transportation acknowledges this and is planning to step up public education efforts as the toll lanes near their opening date.

“I think it’s a disconnect between hearing stuff and the actual visual of seeing something on the road,” said Jill Goldberg, who has been appointed as GDOT’s “toll lanes ambassador.” “That’s when they go, ‘Look at this, it’s huge!’”

Because of its complexity and scope, the Northwest Corridor can be somewhat difficult to envision.

Phyllis Silverman left a recent Kiwanis Club meeting at West Cobb Senior Center with only a hazy understanding of how it will work, even after hearing the project manager’s 10-minute presentation.

“It’s very interesting, but I wasn’t able to follow it well,” Silverman said. “The entrances and the exits and the going south and the flyovers. After a while, it really was very confusing. I think it’s going to take the public a while to catch on.”

Goldberg often gets inquiries from people who think it’s three or four projects, rather than one long, 30-mile stretch of toll lanes that fork at the divergence of I-75 and I-575.

“We don’t usually do a project that is 30 miles long, especially in metro Atlanta,” Goldberg said. “They don’t realize it is different segments of one project and it’s all going to come together.”

Nuts and bolts of a monster project

So what is the Northwest Corridor?

On I-75 from Akers Mill Road up to the I-575 split, two toll lanes are being built along the west side of the freeway. More than five miles of the lanes will have to be elevated so that they soar above existing development and highway interchanges, said John Hancock, project manager for GDOT.

The project's 39 bridges will feature 241 bridge columns and 219 spans, as well as 63 retaining walls and 45 sound barrier walls. The toll lanes will leapfrog an intersection here and duck beneath an interchange bridge there as they progress toward the Perimeter. The one thing they won't do is tunnel underground.

If you’ve ever driven — or more likely crawled through — the I-285/I-75 “Cobb Cloverleaf,” you might like the idea of rising above that contemptible interchange on the tallest highway bridge in the state. That 10-story flyover is one of three new flyovers that will be added to the existing scheme.

David Welden, president of Lost Mountain Kiwanis club and member of a citizen committee looking at adding toll lanes along I-285, said the project is an engineering marvel.

“All the way around it’s just been a smart project,” said Welden. “I think it’s an exquisite design. The best improvement in traffic flow in the history of Atlanta.”

Novel as the concept may be to Atlanta, it’s not a particularly remarkable project in the United States. Ginger Goodin, the policy center director for Texas Transportation Institute, said there are similar “mega projects” involving multiple tolled lanes in Dallas and Houston that each cost more than $1 billion. And the first reversible tollway was built in San Diego in the late 1990s.

The most expensive project, for now

Farther north beyond the I-75/I-575 split, three slip-ramps on I-575 will enable drivers on the non-tolled highway to "slip" over into the toll lane through a break in the concrete barrier.

NEXT WEEK: State transportation planners are gambling a billion dollars-plus that drivers fed up with traffic will be willing to use a network of toll lanes planned for metro Atlanta. But are Atlantans ready to embrace toll lanes?