By the early 2020s, cars and trucks could well be swapping data with each other automatically while cruising the nation’s highways and streets, providing a broad platform to improve safety and save lives, if a proposed new federal rule on vehicle-to-vehicle connectivity is enacted.

ARLINGTON, Va. — The Federal Motor Carrier Safety Administration is trying again to produce a rule on minimum training standards for entry-level commercial vehicle drivers — a goal of the U.S. government since 1985.