Car Tech 101: A traffic signal system inside your car's dash

Audi has been showing a system where the traffic signal you're at also shows up on the instrument panel. You see how long the light will be in its current state, also what speed to maintain to hit the lights without stopping and starting to waste brake pads and fuel. And the car's automatic start/stop system gets smarter because it knows the future of the light, not just your pressure on the brake pedal. Now, no matter how much you shrink down that processing power, you've gotta get data on what the state of the traffic signals are in the metro. How do you do that? Replace millions of traffic signals with something that beams information to cars? That's not practical. Instead, the way Audi's got this working is they've tied in to the network operation center of the Metro Traffic System. Big cities all have this. That data on traffic light state gets sent over to Ingolstadt, Audi's headquarters, processed into the right database structure for the cars to understand, and then sent back out to them through the built-in Audi data radio and the MMI head unit. That's a long way to go to move that data, but it doesn't take long and it's an efficient way to gather the information as opposed to getting every light in the city to talk to cars. That's just not practical. And since this is a mostly passive technology, it wouldn't suffer the hurdles that face regulation and acceptance of self-driving cars, for example. What's really happening here is momentum conservation, a key but typically undersung concept in vehicle maintenance and fuel consumption reduction.