Scientists at Massachusetts Institute of Technology (MIT) have developed a programme that can predict when traffic lights will turn green and show the driver the best speed to maintain in order to avoid having to stop.

Initial trials suggest that it can lead to a 20% fuel saving, not to mention a less stressful driving experience. The system works by mounting a smartphone to the windscreen, (just like you would position an aftermarket sat-nav system). The phone takes photographs of the traffic lights being approached and uses an algorithm to work out when they are likely to change. It also works collaboratively, so that the more cars using the system, the greater the accuracy.

So far, it is accurate to within one second for traffic lights on pre-set phasing. For those traffic lights that change dynamically according to traffic flows, it generally works with an accuracy of slightly more than one second, with a worst-case time of 2.45 seconds.

The system could also reduce pollution: you only have to look at an old bus or taxi pulling away from the lights to see how much worse emissions are when a vehicle (especially an older diesel) is accelerating, than when it is cruising.

The system has been under test for about a year now, and the developer, Emmanouil Koukoumidis, says there are discussions going on with commercial partners in various countries.

Incidentally, if you were wondering about using the system to get ahead of an impending red light, the scientists have thought of that. For safety reasons, the system will only advise you to slow down, never to speed up.