Scientists at Australia's Monash University say that singing while driving is mentally demanding, and takes the edge off your driving skills.
In their experiment, singing drivers tended to slow down and were less attentive to hazards than those driving with no music.
They also tended to stay in the same lane, even when they should have moved over.
But there was a surprise - drivers listening to music were the slowest drivers of all.
By the way, the researchers didn't want to be spoilers. Several of them belong to amateur singing groups, and more admit to singing behind the wheel.