Traffic lights are an essential part of keeping chaos at bay on our city streets, but the idea didn't exactly get off to a flying start. The first gas-lit traffic light appeared outside the British Houses of Parliament in London in December 1868 but exploded two months later (which was bad news for the policeman operating it) and when the first electric lights appeared in the U.S. in 1912, apparently no-one wanted to stop for a “flashing bird house.”
Gradually the technology improved and interconnected lights that could be automatically rather than manually controlled appeared in the 1920s. Now we could be seeing another great leap forward - traffic lights that talk to cars. That's the basis of Audi's travolution project which sets up a dialogue between vehicles and traffic lights in order to keep traffic flowing, save fuel, reduce emissions and possibly help keep drivers saner in the process.
The networked approach to traffic management is known as "car-to-x communication" and Audi's travolution is part of this emerging field which aims to make roads safer and more efficient. At the heart of the Audi system is a self-learning algorithm developed which controls the traffic signals. The latest version of uses wireless LAN and UMTS links to relay information between lights and vehicles, as well as gathering taxi floating car data (Taxi FCD) and information from the ADAC (General German Automobile Association).
This data can then be shown as a graph on a dashboard mounted display, giving the driver real-time access to several very useful pieces of information including:
- the speed to adopt so that the next traffic light changes to green before the car reaches it (which can then be set using adaptive cruise control)
- a traffic light that you are approaching is about to switch to yellow or red (a brief interruption to the flow of power from the engine or a visual or acoustic warning is given)
- how long you need to wait at a red light before it turns to green again
- an overview of traffic jams in the area
The network approach has the added bonus of providing online payment at filling stations and parking garages - where data on the in-car monitor lets you know how many parking spots are still available. Now that's technology at work!
Audi says the system can reduce the amount of time spent at a standstill and cut fuel consumption by 0.02 of a liter for every traffic-light stop and subsequent acceleration phase that can be avoided. This translates to around 5 grams of CO2, which, when you consider that Germany has 60,000 traffic lights, could reduce the country's exhaust emissions by two million tonnes of CO2 annually, or 15 percent in CO2 from motor vehicles in urban traffic.
The travolution project was first trialled in 2006 with reduced waiting times at traffic signals cutting fuel consumption by 17 percent. Fifteen test vehicles and 25 traffic light systems are now being examined under actual traffic conditions in Ingolstadt. There are plans to extend this to another 27 systems - a total of more than 150 traffic lights. Both WLAN and UMTS communication is being tested.
Audi has worked on the project with the City of Ingolstadt, Scheidt & Bachmann GmbH, TaxiFunk Ingolstadt, ADAC (General German Automobile Association), GEVAS software GmbH, the Technical University of Munich, Ingolstadt University of Applied Sciences and the University of Erlangen-Nuremberg.