Monday, May 26, 2008

Toll Road Conundrum

It seems to me that if gas keeps going up and VMT goes down, how are toll roads and congestion pricing on new roads at the periphery going to add up. The formulas that say whether a road would be a good investment for private companies seems to be determined by models with low gas prices, so how will this add up in the future with less driving? I'm not sure how all this works, anyone have some insight?


arcady said...

It used to be that VMT demand was constrained by capacity, but now it is increasingly going to be constrained by gas prices. How that works out depends on where you are: if there's hardly any congestion, then VMT will decrease, but if it's a very congested corridor, then VMT reductions due to higher gas prices are partly offset by increases due to reduced congestion. In general, toll facilities will still make a lot of sense in their traditional niche: bridges and tunnels and other bottlenecks.

M1EK said...

The peak demand is mostly due to commuters - and that peak demand is what the planners figure will be most attracted to toll facilities. People driving for work don't change their behavior much in the short-term, and are singularly unlikely to switch to transit in most cases due to very low variable costs of driving and very high time costs of transit.

As in my case, the transit trip is 2 buses + a 25 minute walk - total time 1:30 to 1:45; the drive is 15-30 minutes; total cost (in Prius) about a buck.