Yes, Virginia Interstate 66 is a mess. Commuters are right to decry the congestion along this stretch of interstate, where travel times from Northern Virginia into D.C. are the longest in the region.
But reports from Dr. Gridlock in the Washington Post that the state and federal governments are considering plans to add additional lanes onto I-66 are not only maddening, but they fly in the face of everything we’ve learned about induced demand.
With years of evidence to back it up, induced demand was defined beautifully in a recent story in Wired, which explained that because “increasing the supply of something (like roads) makes people want that thing even more … the ways we traditionally go about trying to mitigate jams are essentially fruitless.”
In other words, it’s impossible to build ourselves out of congestion because the roads themselves cause traffic.
While the Virginia Department of Transportation’s (VDOT’s) plan to implement “Active Traffic Demand” along the interstate is a better plan, VDOT’s request for proposals from private corporations indicates that the agency is also considering large, engineering- and infrastructure-intensive solutions to I-66’s problems.
Instead, why not entertain these much cheaper (and probably more reliable) solutions:transportation demand management (TDM) and use of high-occupancy vehicle lanes?
VDOT has been very good at congestion management when it has done big projects. Think back to the Mixing Bowl project, the Wilson Bridge Project, and the Mega Projects. VDOT pours money into transportation management programs (TMPs) that are designed to communicate about the problem and encourage people to share the ride, use transit, or avoid the area at peak times.
Yet at the end of each project, VDOT packs up its bag of tricks and leaves thinking that the job is done. Imagine if the kind of intensive effort VDOT gives as projects unfold were also applied to a corridor day in and day out, year after year. Could results be achieved? I think so. VDOT could spend $5 million to $10 million per year – not a lot for the agency – and do some really sophisticated TDM marketing and incentives.
VDOT could work with employers in D.C., Arlington, and Fairfax. It could promote carpooling and transit. It could provide incentives. It could provide real-time vanpool and commuter bus information. This stuff works. We’ve proven it in Arlington.
One could couple these TDM programs with HOV-3 both ways during the rush and HOV-2 at all other times to ensure that road use on I-66 is maximized. Getting the best use out of the existing facility (demand management) is what VDOT should concentrate on, not continually trying to increase the supply. It doesn’t work.
HOV-3 and TDM will work, will be more cost efficient, and are better long-term solutions for everyone.
Cross posted on http://www.MobilityLab.org on July 3, 2014