PANAMA — Here comes the Diablo Rojo, the Red Devil bus blasting its air horn and fishtailing around a fellow “demon” just in time to claim Irma Betancourt and other morning commuters. Suffice it to say the Red Devils earn their name.

“They are crazy,” said Ms. Betancourt, 33, a housekeeper at a downtown hotel, boarding on a main boulevard. “We all know that. All they care about is getting the fare. So many times we have almost hit somebody.”

“Almost” may make her bus one of the lucky ones, as they are known to have taken more than a few souls for the sake of a pickup.

Her bus on a recent morning is like hundreds of others, a converted, cast-off American school bus ablaze with color, usually heavy on the red.