Cars Will Talk to One Another. Exactly How Is Less Certain.

The Cadillac CTS is racing toward a blind corner, raising the anxiety of its passengers. Suddenly, a chime sounds and a “front cross traffic alert” warning flashes on a screen attached to the windshield. Even though there’s nothing visible ahead, the driver jams on the brakes — just as another Cadillac CTS jumps out from around the corner. Disaster averted.

This near miss is all for show — a demonstration of vehicle-to-vehicle, or V2V, communications.