The trick, said A. Lee Swindlehurst, a professor of electrical engineering and computer science at UC Irvine, is “to find a sweet spot where only the driver’s device is jammed,” regardless of where he or she holds their phone. This is technically feasible, he said, “but it would be a challenging design.” [Subscription required, you can request an electronic copy of the article by sending an email to communications@uci.edu.]