Changing Travel Behavior: Punishment vs. Reward

Being in the business of finding ways to change travel behavior, I have dabbled in both reward and punishment. Charging for parking as a tool to get employees not to park in on-street spaces is a form of punishment, while giving out iPods to those who carpool a certain number of days each month is a reward. I have never thought that one might be more effective than the other until I read Eric Jaffe's piece, "Should We Pay People to Drive Off Peak," in Atlantic Cites Place Matters.

He writes about a group of researchers led by Taede Tillema of the University of Groningen, in the Netherlands, who recently designed a study to compare the effects of congestion pricing (punishment) to a Dutch program called "Spitsmijden," or "peak avoidance" (reward).

"In an upcoming issue of the journal Transport Policy, Tillema and colleagues report that a reward system like "Spitsmijden" may indeed be more effective than punishments."

The researchers combined data from a previous study and a previous survey and found that paying people not to drive during peak times changed behavior 37% of the time, whereas boosting tolls during peak times changes behavior only 15% of the time. A nagging question, as the author points out, is if paying people not to drive during peak times works best, who will pay them?

Congestion Pricing Only True Road to Relief

How do you relieve traffic congestion? The assumption is that you either need to build more roads, more transit, or both. And most of the time, this pits transit advocates against road advocates. Well, maybe neither is necessary.

In a new study published in this month's American Economic Review and reported by Eric Jaffe for The Atlantic Cities called The Only Hope for Reducing Traffic, researchers contend that congestion pricing is the only solution to decrease congestion.

Two economists from the University of Toronto analyzed data and road capacity in U.S. cities from 1983 to 2003 and found that there is such an enormous latent demand for road space, they believe that whenever a new lane is built or a driver shifts onto public transportation, another driver quickly grabs the open space.

They believe congestion pricing programs are the only things that will decrease overall car use and delays during peak hours.

StreetFilms.org produced a video on congestion pricing in March:
http://www.streetfilms.org/mba-congestion-pricing/

The US DOT put out this report on congestion pricing in October 2008:
http://ops.fhwa.dot.gov/publications/fhwahop08039/cp_prim1_00.htm