One of the features of speed limiters
But the drivers know they are fitted, don't they? So why do they even attempt such manoeuvres when they know full well they'll be blocking two lanes (or three, if they're on the M5 south out of Bristol) for the next 20 minutes?
For every car driver who doesn't understand the physics of trucks, there's probably a truck driver who doesn't give two hoots about getting in the way of cars trying to make progress.
