Why the I-77 Express Lanes Make Sense
By Robert Poole, Director of Transportation Policy, Reason Foundation
Critics of express toll lanes for I-77 in Charlotte argue that widening I-77 with a regular lane each way would provide greater congestion relief. Indeed, some critics claim that adding the express lanes will make congestion worse. These claims fly in the face of congestion reduction achieved in other metro areas.
Express toll lanes make sense when an expressway is projected to have a long-term congestion problem due to ongoing economic growth, and cannot be indefinitely widened. The more cars try to crowd into a regular lane, the slower they get—and eventually the flow rate gets as low as 800 cars/lane per hour in stop-and-go traffic. With an express toll lane, the idea is to use a price to prevent that overcrowding, letting in only enough cars to ensure free-flowing conditions—about 1,800 cars/lane per hour.
What would rush-hour look like on I-77 about 20 years from now, if I-77 were widened with one regular lane each way (making five each way)? Assuming continued economic growth and congestion, each lane could well be at 800 cars/hour—or 4,000/hour for the five inbound lanes. Under the express lane alternative, the two express lanes each way could handle 1,800 each, and the three regular lanes 800 each, for a total rush-hour throughput of 6,000 cars/hour—50% more than the non-priced alternative.
Results like these are seen every day on formerly gridlocked I-95 in Miami, I-85 in Atlanta, and SR 91 in Orange County, California, all of which are significantly less congested thanks to the addition of express toll lanes. And those results are sustainable long-term, thanks to the variable toll rate that prevents the express lanes from getting over-crowded.
Express toll lanes are now in operation in Atlanta, Dallas, Denver, Houston, Los Angeles, Miami, Minneapolis, San Diego, San Francisco, Seattle, and the Virginia suburbs of Washington, DC. Every metro area that has built an initial project has found it so beneficial that it has planned and added express toll lanes in other congested corridors, with a growing number of them planning a whole network of such lanes.
Critics refer to express toll lanes as “Lexus lanes,” implying that they are used only by the wealthy. In fact, data from Atlanta, Los Angeles, Seattle, and Washington, DC shows that the most common vehicles in express toll lanes are Chevys, Fords, Toyotas, and Hondas. Most people choose the express lanes only for trips where getting somewhere on time is worth the price of the toll.
Express toll lanes and networks are also a boon for transit riders. They give express buses the functional equivalent of a bus-only lane, but without the transit agency having to come up with the hundreds of millions of dollars in infrastructure cost. Instead, toll revenues pay for most of the infrastructure cost.
Express toll lanes are a win-win proposition. They provide sustainable, long-term congestion relief, an alternative for motorists otherwise stuck in gridlock, and a platform for greatly improved transit service. That combination is hard to beat.
Robert Poole is Director of Transportation Policy at the Reason Foundation, a nonprofit public policy think tank. He has advised state DOTs, the Federal Highway Administration, and the Federal Transit Administration on transportation policies.