Using complex mathematical models, the researchers described a system that would use collision detection sensors fitted to manned and autonomous vehicles that would allow the vehicles to share distance and speed telemetry. In theory, allowing vehicles to share information could decrease traffic bottlenecks and increase efficiency and safety at intersections. To do this, the system would provide specific spaces or "slots" for each vehicle approaching the intersection. When a vehicle reaches the intersection, the system puts it into its assigned slot and moves the vehicle through the intersection, allowing traffic to keep moving and removing the need for traffic lights. This system wouldn't require self-driving cars, just cars that could communicate with one another.
An abstract of the study posted on PLOS One describes the study this way:
"Results theoretically show that transitioning from a traffic light system to SI [Slot-based Intersections] has the potential of doubling capacity and significantly reducing delays. This suggests a reduction of non-linear dynamics induced by intersection bottlenecks, with positive impact on the road network."
"An intersection is a difficult place, because you have two flows competing for the same piece of real estate," Carlo Ratti, director of the SENSEable City Lab, part of MIT's Department of Urban Studies and Planning, and a co-author of this study, told the Christian Science Monitor. "On the other hand, if a system has advanced technology and lacks traffic lights, it moves control from the [traffic] flow level to the vehicle level. Doing that, you can create a system that is much more efficient, because then you can make sure vehicles get to the intersection exactly when they have a slot," added Ratti.