Most likely to improve congestion? Pavement

If you want a big improvement to the commute from hell, you need a lot more than tolls — you need more pavement.

Toll lane projects elsewhere in the country that saw the biggest improvement in the overall commute — not just for those in tolled lanes — added at least one lane of travel, and often more.

That includes I-95 in Miami, a darling of the tolling world.

The Miami 95 Express kept the same number of general purpose lanes, converted the previous HOV lane into a tolled lane, and added an additional tolled lane.

Before tolling, average speeds during the morning commute were at 20 mph in the carpool lane and 15 mph in general purpose lanes. By the end of 2014, commuters cruised along at an average 48 mph in the general purpose lanes, and at 62 mph if they paid for the express option.

For general purpose lane drivers, that’s an improvement of 220 percent.

Talk about Florida sunshine.

Other toll lane projects that involved adding pavement — I-15 in San Diego, the Katy Tollway (I-10) in Houston — also saw big improvements. Although similar to other areas, travel speeds have started to dip again as the economy improves.

Without major new infrastructure, toll lanes appear to have far less impact on the general commute — and sometimes don’t even improve the reserved lane commute.

Minnesota opened toll lanes in stages in 2009 and 2010 on the I-35W corridor through Minneapolis, converting HOV lanes. The toll lanes have been a success, keeping people moving at a good clip nearly all of the time. But speeds in the general purpose lanes have varied widely, according to a 2014 evaluation. In the southern stretch of the corridor, average general purpose lane speeds dipped by 1 to 2 mph compared to the year before tolling started.

A few months after opening its express lanes on I-110 in December 2012, Los Angeles County also saw traffic in general purpose lanes go slower. A final report of the program’s first year showed average speeds little better than before the project — and in the HOV-converted express lanes, too.

Today, the express lanes on I-110 are so clogged at times that they’re no longer open to toll-paying customers.

Other places have seen similar problems.

Exacerbating factors can be caused by toll lanes themselves, which often are accompanied by a drop in carpooling and more drivers entering the road at the peak hours they previously avoided.

There’s a fundamental law of congestion at work here.

Increase capacity whatever way you want, but people are going to fill in those gaps — if not right away, then eventually.

“That is generally true,” said Mark Burris, a research engineer with Texas A&M Transportation Institute.

But it’s important to focus on the human element, he added. “You have improved the lives of those people. Maybe they were traveling at 5 a.m., and now they’re traveling at 7 a.m. … I try to remind folks that, yeah, the traffic may fill up again, but that’s from people who have made a change they wanted to make. Maybe they can spend a few extra minutes at home with family now … because we’ve improved the commute.”

It remains to be seen if tolling substantially improves the commute on I-405 this fall.

The project involves converting the HOV lane to an express toll lane in both directions from Lynnwood to Bellevue. But in the southern stretch, south of Highway 522, the state also is widening the highway to add a second toll lane — the same kind of upgrade seen in Miami.

Every toll lane has its own story and results. They are, by nature, highly regional animals. Different states use different toll vendors. Some require carpools to use transponders, others don’t. Lanes in one place may be physically separate from general traffic, while in another they run side by side.

Patty Rubstello, director of toll operations for the Washington State Department of Transportation, urges people to reserve judgment on the I-405 express toll lanes until they’ve tried them out.

“If you haven’t used it, people are pretty skeptical of it,” she said. State focus groups have shown that, once people have experience with toll lanes, they like them enough to want more of them.

“It is about getting a reliable trip,” she said.

Just don’t bank on it being in anything but the fast lane.

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