Eric Jaffe at Atlantic Cities summarizes some of our recent research:

HOT Lanes Are Even More Popular When They’re Expensive:

“Everyday, sometimes twice a day, commuters in the increasing number of U.S. metro areas with a HOT lane ask themselves that timeless question: to pay, or not to pay. How they answer depends on the toll price, which charges single-occupancy cars for HOT access based on congestion levels. Logic suggests that as the toll goes up, fewer drivers would fork over the money — for the same reason we sit coach on a plane once we see the price of first-class.

But in Minnesota, at least, HOT lane prices are having the opposite effect. As the cost of HOT lanes on Interstates 394 and 35 went up, more commuters were willing to pay the toll. That’s the rather counter-intuitive finding that emerges from recent research by Michael Janson and David Levinson of the University of Minnesota [PDF]:”

This positive relationship between price and demand is in contrast with the previously held belief that raising the price would discourage demand. …