While individual companies may have had such rules in place, there was no law backing up the rules.

In a unanimous vote, the CPUC approved the order. The ruling comes less than a week after a Metrolink commuter train ran head-on into a freight train, killing 25 people and injuring more than 130 others, after the operator failed to stop at a stop signal.

As I noted in my earlier story, the Metrolink train engineer, Robert Martin Sanchez, 46, was text-messaging on his cell phone while on duty. Authorities have not determined if he was texting just prior to the crash.

Sanchez was killed in the accident.