In Japan, Toyota has deployed technology called ITS ("Intelligent Transportation Systems"). ITS uses the recently vacated 760 MHz spectrum to communicate with traffic signals and with other vehicles that have ITS installed.
So, your car will know when that traffic light you're approaching will be turning red and slow down in anticipation. Using sensors in the intersection it could warn you and take action to protect pedestrians. Your car could potentially know how fast the car in front of you is going and match their speed.
|An intersection in Japan equipped with ITS (image: Toyota)|
|An example of an ITS warning on your dash display (image: Toyota)|