When the Going Gets Tough
Transportation studies professor Asad Khattak applies his expertise to traffic congestion in Virginia

Imagine all the predictable bottlenecks such as bridges and tunnels that would frustrate the evacuation of Hampton Roads ahead of a dangerous hurricane. Then factor in the unpredictable complications that come when a fearful, ill-prepared and irrational populace flees a storm. Wrecks happen, drivers run out of gas, debris and water block roadways, gridlocked cars are abandoned in the middle of the highway. Asad Khattak, the Batten Endowed Chair in Transportation Systems at Old Dominion University, studies worst-case congestion scenarios in order to keep them from happening.

Since coming to ODU’s Batten College of Engineering and Technology in 2006 from the University of North Carolina at Chapel Hill, Khattak has developed and directed the college’s Transportation Program, which has been ramped up to offer bachelor through doctorate degrees with options in transportation studies.

Khattak also has tackled research, and none of his projects is more momentous than a $300,000 study ordered by the Virginia Department of Emergency Management (VDEM) of the adequacy of emergency evacuation plans for Hampton Roads.

The transportation program is progressing as ODU administrators had planned, said Oktay Baysal, dean of the Batten College. “Old Dominion wants to be part of the transportation solution. We allocated an endowment and recruited a nationally renowned expert, Dr. Khattak.”

With the Hampton Roads evacuation study, Khattak is putting his expertise to use right in the university’s backyard. The study, which runs through the spring of 2008, is being administered by ODU’s Virginia Modeling, Analysis and Simulation Center (VMASC) and directed by John Sokolowski, VMASC research professor and director of research. It focuses on evacuations that are ordered when hurricanes are threatening the region and will address the aforementioned complicating incidents—wrecks, vehicles running out of fuel, and what have you—that have reduced the efficiency of hurricane evacuations elsewhere. Standstill traffic and blocked roads, for example, are what many Americans remember about evacuations in Texas for Hurricane Rita in 2005.

Predictable Patterns of Congestion
“A lot of evacuation plans do not really account for unanticipated incidents, the crashes, et cetera, that cause half of the everyday roadway congestion,” said Khattak. The other half of congestion happens even without unanticipated incidents at peak traffic flow periods such as workday rush hours and is called recurrent congestion. Because it can be anticipated, recurrent congestion is easier—but by no means simple—for planners and engineers to address.

If a high-category hurricane were headed for Hampton Roads and mandatory evacuation were ordered, the potential for congestion would probably develop in patterns we have seen before, Khattak said. “In a sense you are creating a recurrent congestion situation compounded by incidents.” In other words, an evacuation nightmare will be something like a tractor-trailer getting wedged in a tunnel just at the start of evening rush hour.

In an emergency evacuation, the congestion problems often are made worse than rush-hour tie-ups by motorists’ fears, indecision and plain old bad decisions. Khattak tells of evacuees who hitch their boats to their vehicles and load the boats with as many of their belongings as possible. (Decisions such as this can put unnecessary vehicles, as well as debris, on the roads.) One example from a Florida evacuation was of a single family that insisted on fleeing in a caravan of several passenger vehicles and an RV towing a boat.

The work of Khattak and VMASC researchers will include an evaluation of baseline evacuation models, one of which is a general model that is widely used in the United States and another of which was prepared by the civil engineering firm that has done evacuation studies specifically for Virginia.

Then the work will bore in on Hampton Roads. A primary area of investigation revolves around the Safety Service Patrols (SSPs), the vehicles with yellow emergency lights that come to the aid of motorists who have run out of gas, had a flat tire or been involved in a fender-bender. SSP operations and their Hampton Roads incident reports over recent years will be scrutinized in order to identify patterns of interruptions in traffic flow. Questions to be answered might include: How quickly can SSPs clear up incidents and what is the relative advantage of having extra SSPs in certain corridors?

Strategies for Evacuations
Emergency managers in all Hampton Roads localities will be interviewed to collect data about recent traffic experiences during hurricane threats. The evacuation plans of these localities, including strategies for communicating with the populace, and channels of emergency response coordination between localities and agencies, will be evaluated. In addition, existing research will be mined for information not only about traffic, but also about the socio-economic factors and behavioral tendencies that might affect evacuation decisions.

Evacuation incident scenarios will be worked into models, and computer simulations will be run to frame overall evacuation planning and to identify the best responses emergency managers can employ to mitigate the effects of unanticipated incidents.

Khattak, who is the editor-in-chief of Science Citation Indexed Journal of Intelligent Transportation Systems, sees potential in the application of information technology to transportation systems. As such, he predicts that the ability of emergency managers to provide real-time information to evacuees just before they leave home and during their travel will be a critical element of a successful plan.

“Information is key, and especially given that we have greater and greater access to information,” he said. “Communication through the Internet, cell phones and other electronic media has been a very effective strategy in difficult situations.”

Land Use as a Solution
Khattak says he became fond of cars at an early age, primarily because of a road trip of several thousand miles from Germany to Pakistan that his family took when he was a boy. His father, a Pakistani military officer, had been posted in West Germany and had taken along his family to experience life in Europe. When time came to leave, the father bought a car and the family drove through Eastern Europe, Turkey, Iran and Afghanistan on their way home. “The route has not been safe since the Soviet Union’s invasion of Afghanistan in 1979,” Khattak explains. “But in those days it was safe and we had a nice car for the trip. It was such a nice journey.” This left him with the abiding interest in cars, and his initial career goal was to build and drive cars. He switched to transportation engineering, without relinquishing his mission to help people have safe and enjoyable journeys.

After receiving his master’s degree (1988) and doctorate (1991) from Northwestern University in civil engineering, Khattak held research positions at University of Oxford and University of California at Berkeley. He was on the faculty of UNC’s Planning Department from 1995-2006. During the past 15 years, he has authored 60 scholarly journal articles and 42 technical reports, and been an investigator for sponsored research and education projects totaling $3 million.

Some of Khattak’s other work relates to transportation safety and sustainable transportation. He has explored land use planning as a means of improving transportation system performance. One example is the neo-traditional residential developments which have a lower transportation impact owing to their higher densities, mix of land uses, and friendliness toward alternative transportation modes.

He admits that he was interested in coming to Virginia because he believes the transportation challenges here are generally greater than they are in North Carolina. He notes one study that rates the Washington, D.C., area including Northern Virginia as the third most traffic-congested region in the country and the Hampton Roads area as 31st most congested. “So the job at ODU represents a growth opportunity for me,” he says. “Transportation is a big issue in Virginia and it has come to be a high priority for the General Assembly.”