One of life's small but satisfying pleasures is hitting the sweet spot while driving across town and catching all the green lights. At the moment, having that happen is a matter of luck, but Audi is developing a system that will make never getting caught by a red light an everyday thing as a way of speeding up traffic while improving fuel efficiency and cutting emissions.
Driving through a string of green lights isn't a question of gremlins or clean living, but of timing. Modern traffic signals operate on a system of preset timers. Sometimes these change depending on the time of day or, as is increasingly common, because the traffic system reacts to changes in the pattern of car movements. In other words, the trick to an uninterrupted journey is to figure out how the lights are timed at that moment and drive at the right speed, so you always hit the intersections when it’s green.
The Audi system works by taking the guesswork out of the equation. Using Audi connect and the Multi Media Interface (MMI) system, the car uses the internet to contact the area’s central traffic computer and asks it for the automated traffic light sequences. From these, the system calculates the best speed needed to hit as many green lights as possible. This speed, as well as red, green and amber icons, are displayed to the driver via the Driver Information System (DIS) located in the central instrument cluster. If the car is already at a red light, it provides a countdown until green and overrides the start/stop mechanism to bring the engine online five seconds before it’s time to go.
One bonus of this is that not only will the system speed up traffic, but improve fuel economy and reduce emissions, since the biggest enemy of fuel efficiency is the constant braking and acceleration of city driving. If the cars keep running, that saves fuel and cuts pollution. Audi says that if used consistently, the system could produce a 15 percent reduction in carbon dioxide emissions and save 900 million liters (238 million gal) of petrol annually in Germany alone.
According to Audi, the system, which would be integrated into its Audi connect infotainment system, is production ready and could be fitted to every Audi model currently in production, pending the approval of local legislation.
A prototype of the system was shown off at January's Consumer Electronics Show in Las Vegas in an Audi A6 Saloon, which ran on the city roads, with testing continuing there using 50 sets of traffic lights. In addition, Audi is also testing the system with about 60 sets of traffic lights in Verona, Italy, while 25 cars are being tested in Berlin with 1,000 lights. Audi has yet to release performance figures, but it will be interesting to see how the system operates in the real world.
Source: Audi
Humans are fallible- how about we wait till cars are networked and and computers are behind the wheel???
The problem, as ever, would be how to manage the period of transition between what we have now and that where all vehicles are part of such an integrated traffic management system. However, the transition would be facilitated by the obvious increased safety such a system would provide. It would follow that all vehicles so equipped would attract (very) favourable insurance rates.
It will also cut down on drivers weaving in and out thru traffic, which is a big cause of road rage and accidents. Less accidents means less traffic delays.
Once this system is in place and co-ordinated with traffic lights, all the nay-sayers will love it.
The problem is that most demand systems are triggered as a countdown when the traffic on the sidestreet arrives and switches the light solely on that timing, not based on the most efficient time to change the light for the main street. That often means that the sidestreet traffic stares at an empty intersection for 30 seconds and the light changes green for them just as 20 cars arrive (and have to stop) on the main street.
An efficient system that would help ALL drivers and save the most fuel would look down the road a few hundred meters in all directions and base traffic signal changes based on the most efficient energy solution IN THE MOMENT. Switching lights based solely on timing, even if it varies slightly during the day, can't be efficient for traffic in both directions as most cross streets are not at consistent intervals.