Major freight railroads will have to maintain two-person crews in most circumstances under a new federal rule.

“As trains — many carrying hazardous material — have grown longer, crews should not be getting smaller,” said Eddie Hall, the president of the Brotherhood of Locomotive Engineers and Trainmen union. He praised the FRA for taking the step President Joe Biden promised. Hall said keeping two people in the cab of a locomotive is crucial now that railroads rely on longer trains that routinely stretch for miles.