For autopilot and humans: scientists propose a fourth traffic light signal

Researchers suggest adding a fourth light to traffic lights - for autonomous vehicles. The new signal, possibly white, will indicate when there are enough autonomous vehicles on the road to adjust traffic.

According to the researchers, autonomous cars could lead to serious changes in traffic lights that were developed over 100 years ago. Henry Liu, a civil engineering professor at the University of Michigan and lead researcher, believes that the implementation of a new traffic light system may be closer than expected.

Researchers at the University of Michigan, led by Liu, launched a pilot program in the Detroit suburb of Birmingham. They used data on the speed and location of General Motors vehicles to adjust the timing of traffic lights. Despite only 6% of vehicles in Birmingham being connected to the GM system, enough data was collected to adjust traffic light timings and improve traffic flow.

In Birmingham, as in more than half of the country, 34 traffic lights operate on a fixed schedule without cameras or sensors to monitor traffic. While more advanced options exist, they require expensive and complex infrastructure changes.

"The advantage of the method is that you don't need to do anything with the infrastructure ... the data comes not from the infrastructure, but from car companies," Liu says.

Daniel Deneu, director of road safety at the Road Commission in Oakland County, Michigan, noted that even minor changes to green light timing in Birmingham reduced congestion. Thanks to future research funded by grants, the plan is to automate traffic lights elsewhere in the county, which could lead to significant improvements.

Fourth traffic light signal

At the University of North Carolina, a team led by Ali Hajbabai, an engineering lecturer, is exploring a different approach. Instead of adjusting existing traffic light signals, Hajbabai suggests adding a fourth light, possibly white, to indicate when there are enough autonomous vehicles on the road to direct traffic.

"When we approach an intersection, we stop if it's red, and go if it's green. But if the white light is active, you simply follow the car ahead," Hajbabai explained.

At the same time, the specific color of the light is not important - the most important thing is to ensure a common understanding and perception of the new system. Researchers acknowledge that implementing such an approach may take several years, as for effective operation, 40% to 50% of vehicles on the road need to be autonomous.

Source: Associated Press