Back-seat drivers are usually labelled as a major annoyance but Mayo's road safety officer Noel Gibbons is calling on them to speak up, not shut up.
Noel Gibbons made the call in light of road fatality figures which show 11 passengers have been killed on Irish roads this year.
He says back-seat drivers could potentially help to avert an accident if they speak up when they see bad driving behaviour.
Mr Gibbons said female passengers are particularly at risk of injury or death. More than two-thirds of the women who died in car crashes from 1997 to 2006 were passengers in cars driven by men.
In that time, a shocking 1,444 women were killed or seriously injured in collisions when men were driving the car.
“Passengers [should] be proactive when the person behind the wheel is accelerating towards fools territory,” said Mr Gibbons.
“Passenger opinion is important. If a driver violates traffic rules, passengers should make a comment.”
Mr Gibbons said such passenger comment could influence a driver in all of the “fatal five” road safety issues – speeding, seatbelts, fatigue, alcohol and drugs, and distraction and inattention.
“A passenger could influence a good outome on every one of those,” he explained. “There is a high risk to the passenger if any one of those fatal five is not adhered to.”