The prickly creatures had a deadly habit of curling up when danger - such as a car - approached.
That meant thousands of squashed hedgehogs a year.
But scientists have found the hogs now run as fast as their little legs will carry them.
Cars bad for hogs
The scientists tagged some hogs and found the wider the road, the more they avoided them and some never crossed a road at all.
When they did, they sped up. So they may have finally figured out that cars are bad for them.