Boston ? The head of the Boston-area transit authority said Saturday he’ll ban all train and bus operators from even carrying cell phones on board after a trolley driver told police he was texting his girlfriend before a collision Friday.

About 50 people were hurt in the underground crash in downtown Boston, though none of the injuries was life-threatening.

The Massachusetts Bay Transportation Authority already bans operators from using cell phones and recently ran an internal ad campaign featuring a poster of an open cell phone that warned employees not to drive “under the influence.”

But general manager Daniel Grabauskas said Saturday the temptation obviously was too great for some.

“I want to remove any temptation by one or two people stupid enough to think a moment of convenience is worth the lives of the people they’re transporting,” he said. “I’m not going to wait for someone to die to institute a policy whose time I think has come.”

Grabauskas said the new ban would apply to anyone working on a train or bus. He said he hopes to have the policy in place within a week.