Driverless Car Buffer Vehicles

Driverless cars would have a smaller padded driverless "bumper" car rolling in front of it that would cause minimum or no damage if it hit a pedestrial or another car. It would also be driverless but with would carry nothing above the drive and sensor systems other than padding.

The heavy, and more dangerous vehicle carrying passengers or freight follows a safe distance behind. In the event of a collision, the trailer vehicle would be very well tuned into the vehicle in front of it that is actively connected to the braking and other crash avoidance systems.

You would need to rope off the area between the two vehicles though so people woudln't do that obnoxious move where they cut into that space in the safe distance you're trying to establish behind the vehicle in front of you such as when it rains.