ANN ARBOR – Researchers at the University of Michigan recently found that the presence of even one connected vehicle on the road can not only improve safety, but it can save energy in traffic as well.
The team, funded by Mcity, demonstrated this on public roads in southeast Michigan through vehicle-to-vehicle communication, or V2V, in which connected cruise control allows automated cars to respond to several vehicles at once. This is opposed to adaptive cruise control, which only tracks the car in front of it.
Using information obtained through V2V, connected cruise control can adjust the speed of a car. The team was able to test a scenario in which a car braked, causing a chain reaction and re-accelerating of vehicles. It is a common traffic scenario that most of us face on our morning commutes, but also results in frequent fender benders if drivers aren't paying attention.
During the test, an automated vehicle with connected cruise control was able to reduce the G-force to brake by 60 percent, improving traffic energy efficiency by 19 percent.
"Automated cars utilizing V2V data will not only perform better, but they can also foster a friendlier environment where few safety hazards sneak into traffic and higher efficiency is possible for all cars on the road," Gabor Orosz, a U-M associate professor of mechanical engineering who led the research, said in a press release.
Although this is a step in the right direction, there are still many challenges automated cars face when sharing the roads with human drivers.
For one, on-board sensors cannot match human eyesight. They aren't able to see through trucks and buses or see around corners, which can lower the car's reaction time in certain scenarios.
Similarly, in automated cars not using V2V data, the sensors cannot see more than one car ahead and therefore cannot promptly respond to a cascade of braking if traffic suddenly slows down.
This is where the risks lie for automated vehicle technologies, and there is still a long way to go with regard to perfecting their abilities.
According to Orosz, within the next few years, major automakers like Toyota, Volkswagen and General Motors will be incorporating these new communication devices in their new cars, but they will not be self-driving.
"Most of these cars will still be human-driven, but they will broadcast their motion information such as position, speed and acceleration," he said. "When an automated car encounters these signals on the road, it can readily pick up such V2V data and see the traffic situation beyond the reach of on-board sensors."