Tailgating Slows Causes Phantom Traffic Jams

According to the CSAIL team, for decades there have been hundreds of academic papers looking at the problem of traffic flow, but very few about how to actually solve it.

One proposed approach is to electronically connect vehicles together to coordinate their distances between each other. But so-called “platooning” methods require detailed coordination and a massive network of connected vehicles. In contrast, the CSAIL team’s approach would simply require new software and some inexpensive hardware updates.

Horn first proposed the concept of “bilateral control” in 2013 at the level of a single car and the cars directly surrounding it. With the new paper, he has taken a more macro-level view, looking at the density of entire highways and how miles of traffic patterns can be affected by individual cars changing speeds (which his team refers to as “perturbations”).

“Our work shows that, if drivers all keep an equal distance between the cars on either side of them, such ‘perturbations’ would disappear as they travel down a line of traffic, rather than amplify to create a traffic jam,” says Horn.

The team’s article was published in this week’s issue of IEEE Transactions on Intelligent Transportation Systems.