Speed radar signs let us know when we're speeding, but they're also incredibly easy to ignore. A flashing light isn't of much consequence. That's why the Missouri Department of Transportation is going to start using sound cannons against speeders.
Two Long Range Acoustic Devices will be deployed in construction zones to blast speeders with a high-pitched sound. The sound cannons are capable of reaching 153 decibels, louder than a firework exploding three feet from your ear, but the Missouri DOT promises to only use them at "safe levels."
Considering the government never uses excessive force, what could go wrong?