"So far, no one has reported empirical evidence from real city-traffic data that the transition Kerner predicted actually occurs," Davis pointed out. "But if confirmed, it will be an important discovery."
With a physical description of gridlock, Kerner plans to come up with ways to break up gridlock in future work.
"Correctly understanding the scenario Kerner studied could lead to congestion mitigation," Davis wrote, "perhaps by dynamically controlling the length of the red and green phases of the traffic light. I'm sure that his paper will generate considerable comment and will stimulate further research."
In the meantime, Mitchell believes that a lot is up to the driver. People can avoid gridlock conditions if they adjust their schedules, or take mass transit. And if they ever find themselves at a congested intersection, in front of a "stale" green light about to turn yellow, they should try to avoid being part of the problem.
"I do think that there is an individual conscious decision to be made whether to move through that green light or sit back and not block the box," Mitchell said.