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

The Transportation Department’s Federal Railroad Administration released the details of the rule the agency has been working on for the past two years Tuesday morning.

The rule comes amid an intense focus on railroad safety following the fiery February 2023 derailment in eastern Ohio.

Rail unions have long opposed one-person crews because of a combination of safety and job concerns.

Unions and regulators say the second crew member plays a crucial safety role in helping operate the train and serving as a first responder if there is a problem.

Railroads have sought the discretion to operate trains with only one person and move conductors to ground-based jobs.