instead they'd better mandate the ultrasound radar in front of the vehicle, similar to parking sensor in the rear, yet with additional chip that would take the speed (and direction of the turn if any) into account to calculate the distance for sound&visual warning to the driver. A cheap solution to so many traffic accidents i see regularly on my commute on 101.
Actually, they did recommend that for commercial vehicles. The NTSB doesn't issue mandates because it's an investigative agency rather than an enforcement one. But none of the news reports include that information because it's boring and doesn't get as many eyeballs.
