When Sikai Chen thinks about “smart” connected driving in the world of tomorrow, three factors come to mind.
Chen focuses his research on these three areas: connected and automated transportation, smart infrastructure, and human-vehicle interactions. After serving since fall 2021 as a visiting assistant professor at Purdue University, he joined the Department of Civil and Environmental Engineering as an assistant professor in fall 2022, and will bring his expertise in these areas to further automated transportation research at the University of Wisconsin-Madison.
Chen, who hails from Beijing, has noticed that traffic congestion is a common problem for big cities around the world. This is true of Beijing, and he’s seen it in Los Angeles and many other places. That motivated him to come to the United States and study transportation at the University of Southern California.
“The more I studied, the more I realized that safety is one of the most important aspects of transportation,” Chen says. “Of course, people talk about congestion all the time, but what really damages society is when we lose people in crashes. What a lot of transportation researchers are really doing is trying to improve safety.”
Chen takes inspiration from Vision Zero—a global effort to eliminate traffic fatalities and serious injuries. Every year, more than 42,000 people across the United States are killed in crashes. Globally, more than one million people die on the road every year.
Although traffic congestion often takes the limelight, transportation safety is where Chen sees the most work to be done. With advances in connected and automated vehicles, he believes that fixing the former problem also enables him to tackle the latter.
Connected and automated vehicles can communicate with one another and with “smart” connected roadside infrastructure. Chen says we can use this ability to help keep traffic flowing.
For example, a road that narrows from three or four lanes to two creates a bottleneck where regular, non-connected vehicles may back up as drivers all attempt to move into the narrower space at once. With even a few connected or automated vehicles, Chen says, we might be able to mitigate congestion in those areas as the vehicles communicate with one another and the smart infrastructure, change lanes earlier at appropriate times, and keep traffic flowing. When traffic flows more smoothly, it reduces the potential for crashes, making the roads safer.
In another scenario, he says connected and automated vehicles with sensors that detect other vehicles may be able to work together to avoid a collision if a human-driven car makes a hard shift from one lane to another without warning.
“That’s called cooperative driving automation,” Chen says. “That allows the vehicles to talk to one another and to smart infrastructure so they can work together to improve safety, efficiency and energy consumption. We can’t solve all of these problems we face on the road with automated vehicles alone, but we can help try to lessen their impact. That’s something I’ve been working on and will continue to research at UW-Madison.”
Of course, automated vehicles come with their own unique challenges. In the future, cars may be capable of navigating roads without drivers. That might introduce new conflict points, particularly in places like crosswalks, where pedestrians and vehicles interact. Chen says it’s natural for pedestrians to look at a vehicle to be sure the driver sees them. In the absence of a human driver, engineers will have to find ways for pedestrians to know they’re safe.
“We’ll have to be able to effectively communicate to pedestrians that the automated vehicle sees them,” he says. “That could be something like a blinking light in the window or some sort of display on the windshield. We don’t want it to be overwhelming so pedestrians have to stand there and stare at the screen.”