Traffic jams occurring on highways cause increased travel time as well as increased fuel consumption and collisions. Traffic jams without a clear cause, such as an on-ramp or an accident, are called phantom traffic jams and are said to make up 50% of all traffic jams. They are the result of an unstable traffic flow caused by human driving behavior. Automating the longitudinal vehicle motion of only 5% of all cars in the flow can dissipate phantom traffic jams. However, driving automation introduces safety issues when human drivers need to take over the control from the automation. We investigated whether phantom traffic jams can be dissolved using haptic shared control. This keeps humans in the loop and thus bypasses the problem of humans' limited capacity to take over control, while benefiting from most advantages of automation. In an experiment with 24 participants in a driving simulator, we tested the effect of haptic shared control on the dynamics of traffic flow, and compared it with manual control and full automation. We also investigated the effect of two control types on participants' behavior during simulated silent automation failures. Results show that haptic shared control can help dissipating phantom traffic jams better than fully manual control but worse than full automation. We also found that haptic shared control reduces the occurrence of unsafe situations caused by silent automation failures compared to full automation. Our results suggest that haptic shared control can dissipate phantom traffic jams while preventing safety risks associated with full automation.

As millions of people travel the interstates over the long Thanksgiving weekend, many will encounter patches of traffic at a standstill for no apparent reason -- no construction or accident. Researchers say the problem is you. Human drivers just don't do a good job of navigating dense traffic conditions, but an experiment using artificial intelligence in Nashville last week means help could be on the way. In the experiment, specially equipped cars were able to ease rush hour congestion on Interstate-24, researcher Daniel Work said on Tuesday. In addition to lessening driver frustration, Work said less stop-and-go driving means fuel savings and, by extension, less pollution.

Did you know there's a specific term for the times when you encounter sudden, inexplicable vehicle congestion on the interstate despite no discernible culprit such as rubbernecking or an accident? It's called a "phantom traffic jam," and was first identified around 12 years ago by researchers in Japan conducting a simple experiment. Despite telling 20 human drivers to all drive at a constant speed around a circular track, even the briefest instances of individuals' pressing their brake pedals compounded on one another, resulting in those recognizable traffic fits and starts. This automotive variation on the "butterfly effect" has been carefully studied ever since, and a research group is now approaching the finish line on a potential solution devoid of any sort of half-baked "self-driving" system. As Associated Press recounts, a recent experiment has shown instances of phantom traffic jams can be reduced by linking cars' into a single communication network via utilizing newer vehicles' adaptive cruise control systems.

A traffic jam, by definition, is caused by all of us. The root cause may be an accident, or construction, or the crush of mid-sized SUVs leaving a Billy Joel concert, but if you're part of the traffic flow, you're part of the problem. But for some kinds of traffic jams -- those that appear for no obvious reason -- there's a not-obvious solution. A single driver, armed with a rudimentary knowledge of fluid dynamics, can dissipate or prevent a miles-long jam. With the same methods, drivers working cooperatively (and aided by some here-and-now technology) could significantly and continuously reduce traffic backups on highways.