Assistant professor of mathematics Dr. Benjamin Seibold juggles studying mathematics, traveling the world, teaching differential equations, creating sculptures and playing ultimate Frisbee. And, to top it all off, he recently completed research on traffic jams. Seibold yielded his busy schedule to talk to The Temple News about his work and how to just “go with the flow.”
The Temple News: How long have you been teaching at Temple?
Benjamin Seibold: I’ve been at Temple University for one year. I taught at [Massachusetts Institute of Technology] for three years and received my doctorate in Germany.
TTN: What is it that you study and teach here?
BS: I specialize in the computation and modeling of flow. This can be the flow of liquids, of photons [and] even of people. I am especially interested in traffic flow. We use models to mathematically simulate real-life situations and make predictions.
TTN: How exactly does traffic relate to flow?
BS: You can treat traffic flow – based, of course, on overall travel and not on the individual cars and drivers – like a detonation wave after an explosion. A detonation wave is similar to, but goes further than, a shock wave. We have models that boil this down to basics. We measure the traffic density and velocity of field just as we would do for a detonation wave. The front moves forward, and pressure condenses in what is called the reaction zone. It is in this reaction zone that the cars begin to get backed up and condense, just like in the wave. We nickname this a “jamiton.”
TTN: So, what happens when we get to a phantom traffic jam?
BS: A phantom traffic jam is named so because no one really knows where it comes from. If you look at simulations, or even real-life studies, there is not a single driver whose fault it is. Cars are all traveling at the same pace, but eventually some will start to slow down or speed up a tiny bit. This ultimately creates traffic jams in which drivers will see the slower cars, react and then slow down themselves.
TTN: You say it’s essentially no one’s fault, so what is the cause of it?
BS: The phantom traffic jams occur, first because of minor perturbations in the road and in human behavior. Once these perturbations reach a certain level called critical density, it becomes a traffic jam. The density of cars is higher, so the traffic is slower.
TTN: What sort of difficulties come up when modeling these jams?
BS: One problem is that it is extremely difficult to predict human behavior and take it into measurable, mathematical situations. We are individuals, not photons. Another problem we run into is that while we can present the math, there are lawmakers and finances that might not allow us to execute our ideal solutions.
TTN: What can we do to prevent “jamitons,” and how important is it?
BS: It is not so much a matter of importance in speeding up people’s days so they do not have to sit in traffic. It is more the fact that these wear out expensive materials that car companies must make. Most importantly, these are hot spots for accidents. One thing we can do is replace permanent speeding zones, with normal [speed-limit] signs, with adjustable speeding zones, with LED signs, that could change based upon conditions.
TTN: Why is traffic flow so interesting to you?
BS: I think it’s a fascinating area. There are so many components. We work with the mathematics of it, but there are also engineers and other scientists we collaborate with. With future technology, we may be able to eliminate these dangerous traffic jams in the next 20 years.
Matt Flocco can be reached at firstname.lastname@example.org.