A map showing the route and interchanges of the I-75/I-575 Northwest Corridor project in Cobb and Cherokee counties. Above the I-575 interchange, one new reversible lane will be added in the I-75 center median to Hickory Grove Road and a similar new I-575 lane will extend to Sixes Road. Drivers will have to pay a variable-rate toll, based on traffic volume, for access to the lanes.
Photo: Kent D. Johnson, kdjohnson@ajc.com
Photo: Kent D. Johnson, kdjohnson@ajc.com

Most drivers unlikely to benefit from I-75/I-575 toll lanes

Call it a tale of two roads.

On one, a driver could travel from Holly Springs in Cherokee County to the Perimeter in 21 minutes.

On the other, the same 15 miles at the same time of day would take 65 minutes.

These two roads are actually a single divided interstate, coming soon. The giant “Northwest Corridor” toll lane project on I-75/I-575 in Cobb and Cherokee counties will be far and away the most expensive road project in state history, with 30 miles of barrier-separated, reversible express lanes. But it will have hugely disproportionate effects on peoples’ commutes.

Drivers who decide to pay a toll will reap enormous benefits, with commute times slashed by as much as two-thirds. Everyone else’s rush hour trip will remain generally abysmal. Several arterial roads that will connect drivers to the toll lanes on I-75 also are expected to become more congested over time as a result of the project.

And it’s unclear whether it will help fans bound for the new Braves stadium to be built at I-75 and I-285. The reversible lanes are supposed to be directed northbound away from that site on weeknights and weekends.

Natalie Dale, a spokeswoman for the Georgia Department of Transportation, said the department just learned of the stadium plans Monday. She said it was far too soon to speculate if the lane direction should be changed for ballgame-goers.

So is the project worth the $840 million price tag?

State officials say yes, because it will provide a faster, more reliable option for people on two of the most congested highways in the city.

“I don’t know how we would have built new capacity for what’s almost 30 miles without tolling as a part of the financing component,” said Chris Tomlinson, executive director of the State Road and Tollway Authority. “And I don’t know how we could try to give some type of assurance to the public of a more reliable trip without using pricing as a strategy to help manage the flow of the lanes.”

Some commuters welcome the toll lanes. Others think asking drivers to pay to drive on a road their taxes already paid to build is highway robbery.

Engineers used complex computer algorithms to project traffic patterns on eight segments of the two interstates in 2018 (the year the lanes open) and in 2035. They found similar trip time disparities between the tolled and untolled lanes in all of them. They also found only a marginal improvement between a few seconds and perhaps 7 minutes in expected trip times in the main lanes, compared to travel time if no express lanes were built.

For example, driving south on I-75 during morning rush hour from where the toll lanes start at Hickory Grove Road in Cobb County to where they end just inside the Perimeter would take a lightning-quick 16 minutes. That’s compared to 39 minutes in the general purpose lane, or 40 minutes if the project were never built.

Similar findings caused great concern when The Atlanta Journal-Constitution analyzed an earlier traffic study for the Northwest Corridor in 2011. At the time, Gov. Nathan Deal’s spokesman Brian Robinson said the study raised “serious questions” that must be answered before the deal was finalized.

He went on to say the governor would not approve any final deal before the questions were answered “through a serious cost-benefit analyses.”

With the date looming for finalizing the contract on Nov. 14, top state officials appear to have changed their tune.

“Of all the options available to the state, SRTA and GDOT have chosen the best one,” Robinson said in an email. “This is greatly needed new capacity, which will give commuters a new option for a quicker, more reliable route to and from work while easing congestion in existing lanes.”

He said, “If we do nothing, the commute times will get much worse.”

Other findings buried in the 856-page traffic study include:

  • Projected transit ridership will increase by 3,000 people by 2035. However, the number of solo drivers on the corridor is expected to remain at 56 percent, with or without optional toll lanes. No money in the project is to pay for more buses.
  • Several arterial roads that provide access to the I-75 toll lanes will become more congested than they would have been if nothing was built. Express lanes are expected to attract more cars and truck, so by 2035, increased traffic volume is projected on South Marietta Parkway (12.7 percent), Terrell Mill Road (8 percent) and Ga. 3 Connector/RoswellRoad (4.8 percent). A GDOT spokesperson said the traffic flow on the roads, particularly South Marietta Parkway, would be slightly restricted but would remain steady and drivers would be able to maintain posted speeds.
  • Reverse commuters — people heading north in the morning and south in the evening — make up about 40 percent of interstate drivers. But details about their expected trip times were absent from the state’s most recent traffic research. Projections from 2011 showed reverse commuters’ trip times would stay the same or even slow by a fraction of a minute.

 

Traffic studies are notoriously unreliable, but they are one of the few measures the public can use to gauge the potential impact of a new road project.

The traffic volume along I-75 south of Delk Road is expected to grow from 298,000 to 301,000 over the next two decades as more people are drawn to the region. If no toll lanes were built, average daily traffic would actually decrease from 292,000 to 288,000.

The projections have some observers questioning whether the return merits the investment.

“You have a small percentage of people who have greatly improved travel times and a large percentage of people who won’t see that,” said Brian Gist, a senior attorney with the Southern Environmental Law Center, which advocates for more transit. “I think we need to be looking at projects that offer everyday solutions for all the drivers on the road.”

A third of the roughly $12 billion budgeted for transportation projects in the region over the next 30 years will be spent on express lanes. A handful of projects are already in some phase of development for I-75, I-85, I-285 and GA 400.

But when it opens in 2018, the Northwest Corridor will be the most expensive. The most elaborate. The granddaddy of them all.

The I-75 and I-575 corridors are home to several business centers including Cumberland Galleria, Marietta and Town Center. Also there are Dobbins Air Reserve Base, a large Lockheed Martin aircraft plant and two universities.

Two optional, reversible toll lanes will be built along I-75 from I-285 to I-575. One will continue up I-75 to Hickory Grove Road and one will run along I-575 up to Sixes Road. The toll lanes will operate southbound in the morning and northbound the rest of the day.

Tolls will increase or decrease based on the amount of congestion, to keep traffic flowing at 45 mph or faster. The rates haven’t been set yet, but generally they range from a few cents to about $1 per mile.

Benita Dodd, vice president of the conservative think tank Georgia Public Policy Foundation, has been one of the biggest advocates for building an entire network of optional toll lanes around Atlanta. She said the state’s traffic projections are probably overly conservative.

“I really think that we’re going to see more trip time savings than are projected,” Dodd said. “I think people are going to understand that this is the way of the future to relieve congestion, because adding capacity is not the answer.”

The state has been studying the idea of I-75 toll lanes since 2002.

Some states like Florida, Pennsylvania and Texas have had toll roads for decades — long enough for two generations to become accustomed to them. Around Atlanta, though, they remain controversial.

Steven Tuday, 43, of Woodstock, has seen toll lanes function well in other states and welcomes them here. He says Atlanta seems to be struggling to build roads for today’s needs, while other cities are already paving the way for the future.

“If they’re not going to put toll lanes in, then probably nothing will ever get built because there is no money,” Tuday said.

Becky Taylor, in contrast, says she won’t pay the toll even if it means a quicker commute. “That’s just ridiculous to me,” said Taylor, 54, of Acworth, who travels on I-75 from her home in Acworth to her job in Marietta. Taylor said she would rather pay higher taxes to fund additional, untolled lanes.

But history tells us that building new interstate lanes isn’t a solution to the city’s traffic woes, said Toby Carr, director of planning for GDOT. That strategy only breeds more development, followed by more congestion.

Just look at I-75, which was just two lanes in each direction when it opened in 1977. Over the years, more and more asphalt has been added. It’s now it’s a 13-lane highway. And it’s still nightmarishly congested.

“No one’s crystal ball is perfect,” Carr said. “But these managed lanes, we are confident will continue to perform well.”

Adding more lanes for free is also unaffordable in the current fiscal climate. According to the state’s earlier estimates, adding two general purpose lanes in each direction on I-75 would have cost $4 billion. That’s more than four times as much as the optional toll lanes, and twice the annual budget for GDOT.

Toll roads can add new lane capacity while at least helping fund their own maintenance costs.

There’s been no comprehensive research about whether optional toll lanes generally improve traffic in the main lanes. But several states have reported seeing universal benefits, according to Ginger Goodin, a national expert on optional toll lanes.

After the construction of High Occupancy Toll lanes on S.R. 167 in Seattle, there was a 21.5 percent increase in average speeds in the main lanes. And after express lanes were built on I-394 in Minnesota, 48 percent more cars were able to move through the corridor during rush hour.

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