Relieving Congestion: LSU researcher gets grant to study traffic problems
If
you could save money by leaving for work 15 minutes earlier than usual,
would you do it?
That is the sort of pricing game that Sudipta Sarangi, an assistant professor in the Department of Economics at LSU’s E. J. Ourso College of Business, will use to evaluate traffic infrastructure in a new study funded by the National Science Foundation (NSF).
According to Sarangi, the study will benefit city planners around the nation, and the results will have much larger implications. “We are really going to delve into social aspects with this study,” he said. “An activity such as carpooling can be indicative of social and community involvement. We may find that where you find neighbors riding to work together, you also find neighborhood watches, stronger libraries, and active civic groups.” These seemingly small details of everyday commuting can have a big impact on communities.
It is often assumed that traffic congestion is the result of an insufficient number of roads. However, Sarangi attributes congestion to a phenomenon called the “tragedy of the commons.” When many people use a resource that no one owns, such as a highway or any other public facility, the resource often becomes overused.
People think, I can take a little extra, or I can drive at this time, because it is what I need, and I am not taking from any person because no one owns the road,” Sarangi said. “When everyone behaves that way, public resources are stressed, and problems such as traffic congestion arise.”
The study will look at ways to mitigate the “tragedy of the commons” in traffic systems without building new infrastructure.
Sarangi will lead a team of researchers from Virginia Commonwealth University and Virginia Tech in the three-year project, which will tackle both economic and engineering aspects of traffic congestion to develop solutions. The total NSF grant for the study is $680,000, of which LSU will directly receive $130,000. Sarangi’s team will also work closely with the Federal Highway Administration, reporting their results and making sure they are asking questions the federal government needs answered.
Researchers will rely on game theory – which addresses any situation in which the final outcome depends on actions of more than one person – during the study, allowing them to fully realize the complexities of individual behavior when using a shared resource such as traffic infrastructure. The study will test two specific strategies for relieving traffic congestion: dynamic congestion pricing and highway space inventory control.
Dynamic congestion pricing involves toll charges for the use of roads, bridges, and corridors. Tolls are generally a set fee. For instance, drivers always pay $1 to cross a bridge. This traffic study will test the effectiveness of implementing varying toll amounts. In this practice, drivers may pay $1 to cross a bridge during the afternoon but pay $3 to cross the same bridge during rush hour traffic.
According to the research team’s proposal, the implementation of Electronic Payment Systems in existing infrastructure has made it possible to consider dynamic tolls.
Highway space inventory control, which researchers call a “more novel” strategy for controlling congestion, would require drivers to reserve driving space in advance. Like purchasing an airline ticket, drivers would make their reservations and pay varying fees according to the dates and times they would like to use a particular road. Those without reservations would be forced to find alternate routes.
Study participants will navigate computer-simulated traffic routes as if they are making their normal commutes to work, run errands, and anywhere else they may drive. After an initial “drive” using their normal or preferred route, participants will be introduced to the additional travel factors associated with dynamic congestion pricing by researchers. For example, if you know that it will cost $1 to cross the bridge at 7:45 a.m. and $3 to cross the bridge at 8:00 a.m., will you leave home to get to the bridge earlier and avoid the higher toll? Would you take a toll-free alternate route, even if it is longer, to avoid the toll?
“If Driver A chooses the normal route and Driver B chooses the alternate route, then traffic becomes more evenly distributed between the routes and congestion is relieved,” Sarangi said. “Ultimately, both drivers will have a better commute.”
The costs associated with traffic congestion are physical – wear-and-tear to a vehicle and rising fuel prices dent the pocketbooks of everyone who drives – and intangible, with environmental costs such as noise and air pollution caused by traffic congestion and lost productivity associated with the time spent sitting in traffic delays.
Solving traffic congestion problems will not just decrease these costs and improve the morning commute for drivers, but also improve the quality of life in communities. According to a 2000 Putnam study cited in the research team’s proposal, an additional 10 minutes of commuting time each day is equal to 10 percent of the time individuals can spend involved in community projects; each extra minute spent on the road is a minute spent away from home.
And while a traffic-relief measure such as carpooling can signal a stronger community, traffic problems and associated costs can prevent social networks from growing. Communities are in danger of becoming insular if the costs of traveling, either physical or intangible, become unmanageably high. According to Sarangi, this geographic tightening of communities and limitation of networks can change suburban and city life as we know it.
Though the study will be searching for ways to reduce travel time for drivers, the research team is not ignoring the social and emotional connections people have to their cars and driving. “People associate driving with freedom,” Sarangi said. While that freedom may be limited by carpooling, public transportation, or reserved highway time, more cars on the road also limits freedom by keeping congestion costs high – if physical, time, and community costs are minimized, then people will have more money and more time to spend on things other than driving.
According to the research team’s proposal, they believe that strategies like dynamic congestion pricing and highway space inventory controls will lead to more effective use of existing traffic infrastructure. That will be welcome news for city planners and policy makers; reducing the costs of traffic congestion and eliminating the need for new roads will prove a social and economic win-win situation for governments and drivers alike.
April Hedges | E. J. Ourso College of Business
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Spring 2006
