Collision-sensing technology is now available in several models of passenger vehicles. Sensors in the vehicles detect when another vehicles is close enough for a collision, alerting the driver with a vibration or a beep.
That technology is great for cars that are right next to one another. What if the vehicles are too far apart for the technology, but a crash is still imminent? This is a common problem at rural intersections, where roads curve around corners and hills make it hard to see vehicles stopped ahead.