How A Few Self-driving Cars can Improve Traffic Flow

According to Daniel Work, assistant professor of Civil Environmental Engineering at the University of Illinois, the use of self driving cars to regulate traffic flow is the next big change in the science of traffic monitoring and control.

The presence of just a few of the autonomous cars can eliminate the stop-and-go driving that we are used to as human drivers in traffic.  It will also help eliminate the accident risk and the fuel inefficiency it costs.  This finding shows that self driving cars and other related technology is much closer to revolutionizing traffic control than we previously thought.

 "Our experiments show that with as few as 5 percent of vehicles being automated and carefully controlled, we can eliminate stop-and-go waves caused by human driving behavior,"

Just as fixed traffic sensors have been replaced by crowd sourced GPS data in many navigation systems, the use of self driving cars is bound to replace classical freeway control concepts such as variable speed limits.  

Field experiments were tested in Tucson, Arizona where a single autonomous car circled a track continuously with at least 20 other human driven cars.  Under normal circumstances, human drivers will cause some sort of stop and go traffic due to their driving.  This is called the "phantom traffic jam".  Researchers, however found that by controlling the pace of the autonomous car, they were able to smooth out the traffic flow of all the cars.  Even a small percentage of these cars was proven to be able to smooth out traffic, eliminate waves, and reduce total fuel consumption by 40 percent.  

"I assumed we would need sophisticated control techniques, but what we showed was that controllers which are staples of undergraduate control theory will do the trick."

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