Rising I-85 tolls scramble the cost-benefit equation

The price of a less-ugly commute on I-85 just went up sharply. Again.

Last week the new increase in express-lane tolls took effect for the busiest stretches of I-85 in Gwinnett County and part of DeKalb.

But we are missing something crucial even with the new record high ($13.95) that resulted: Knowing in advance how much time we’ll save for the money.

It’s a blind spot that should be at least partially fixed when the state rolls out dozens of miles of new toll lanes already under construction in Cobb, Cherokee, the Southside and north Gwinnett. That’s important because more and more of us have a decision to make: Whether to take the free lanes or the paid ones.

We aren’t well suited for that kind of quick decision. Researchers have concluded we are awful at estimating the passage of time when stuck in traffic hell.

Which probably means trying to make a cogent cost-benefit decision about whether to jump in a toll lane while sitting in traffic is like shopping for groceries when you’re hungry.

“When I get stuck in congestion it feels like I am going much slower and losing much more time than I actually am,” said Mark Burris.

He’s a Texas A&M professor who despises sitting in gridlock and studies the surprisingly complicated issues around how much we’re willing to pay to save time and avoid traffic. One thing he and other researchers have noticed: We overestimate what we are getting from toll roads.

“People feel they are saving two or three times as much travel time as they are,” Burris said. “We attribute that to people really, really dislike sitting in traffic.”

I’ve driven the Gwinnett express lanes more times than I want to admit. (Except, I just did.) The toll changes regularly in order to avoid too much congestion, which is a nifty market experiment. Except that it doesn’t always work.

Toll lane drivers almost always seem to move faster than their friends in the general lanes. But that doesn’t mean the toll people always get what they expected.

Sometimes the 15.5-mile-long toll lanes are turbocharged escape chutes. And sometimes they have bottlenecks that make toll-payers feel like suckers.

Not so transparent

The state posts current average travel times for the general lanes, but not specifically for the express lanes.

Talk about a lack of transparency in shopping decisions.

Chris Tomlinson, executive director of the State Road & Tollway Authority, said signs near the new toll lanes coming for Cobb, Cherokee and Henry counties will display speed comparisons between the toll lanes and general ones. That’s a good move. State officials will make other changes with the new toll lanes. For starters, they’re building brand new lanes. That avoids the massive marketing blunder they made in Gwinnett, where they took an existing free lane and started charging for it. (It was a free HOV lane for carpools of two or more people. Now, it’s for registered users who pay or have at least three people in the vehicle or meet other exceptions.)

How much time do the existing express lanes already save in an average rush hour? And what’s the average cost of those time/ stress savings?

The tollway authority says it has a hard time coming up with those figures. Southbound morning rush-hour speeds in the toll lanes averaged 59 miles per hour over the last year, according to the authority. That’s below the current 70 mph speed limit but faster than the 44 mph average in the general lanes.

As toll prices rise, so should our expectations of what it is we are buying.

Actually, that’s part of the reason the State Road & Tollway Authority is raising prices at peak hours on the most congested sections of the toll lanes.

It wants to price some motorists out of the lanes (perhaps to move to alternative roads or alternative times). The express lanes have grown too crowded to meet federal standards, which mandate an average of at least 45 miles per hour 90 percent of the time during rush hours over six months.

Nudging people out might be tough. Prices at peak hours have soared in recent years, yet thousands more drivers pack into the lanes.

A premium on movement

“People do put a premium on their time or a premium on movement,” Tomlinson said.

On Monday a full ride jumped to $13.95 (the max allowed by the state), compared to the previous high of $12.

Higher-income drivers tend to use the lanes most frequently, but even lower income drivers chose to pay for access, an earlier study by a Georgia Tech PhD candidate found.

“It is not a Lexus Lane. It is more like a Ford 150 and a Camry lane,” said Randall Guensler, a Georgia Tech engineering professor who digs into this kind of stuff.

What consumers are willing to pay to save time and boost reliability depends on their life at that moment, he said.

Late for a job interview for a sweet position that pays $100k? Maybe $13.95 looks like a bargain.

There’s even a hypothesis that when some drivers see high tolls they steer into the express lane, assuming they must really need it if the price is that high, Guensler said.

Most I-85 toll-lane drivers don’t use the safety net every work day. And only 10 percent of trips go the full distance of the lanes. Which might be partially a sign of consumers re-calculating their purchase decision as they drive.

It’s tough for most people to make a habit of spending $13.95 on a one-way toll. Add in a round trip and that would be about $140 a workweek or close to $7,000 a year.

Is Atlanta’s traffic that bad?