If any government was "really" interested in stopping people from driving at what they think is a safe speed... they could put $2 IR transmitters on speed signs and mandate (like seat belts, etc) that cars have an IR receiver and when you exceed the ridiculously slow speed you get a constant beep.
Example: Doggie get's on the freeway, the speed sign transmits that the speed limit is donkey trot speed, an IR receiver in the cars headlights picks it.
When doggie sneezes, and puts a little extra pressure on the gas pedal taking his speed to donkey gallop, the car starts to beep.
This is the same tech as your TV remote control.
In Saudi Arabia cars emit a constant beep when you exceed 100kmh.
Unfortunately there's still nothing from stopping from falling asleep from driving as such brain numbing speeds.
Anyway doggie, you just got rob by a highway bandit, toughen the farkup