The idea is that the computer in your car would know where you want to go and when the various traffic lights around town will change, and it would use this information to tell you how fast to go in order to travel most efficiently. This could include features like avoiding traffic jams etc (this part is definitely baked), but the main (and more commonly used) purpose would be to queue the driver on how fast to drive/accelerate and which turns to make in order to minimize travel time (legally) and minimize starting/stopping. This would get you to your destination sooner, and conserve gas.

The display hardware incorporated into this would ideally be a stereoscopic system of some sort (HUD, etc), though a poor-man's version could simply use faster/slower arrows, a dial, etc. In the stereo version, the "target speed" could be represented as a very translucent 3D car/box that would float in front of the driver's car, and which the driver would try and follow. (The "phantom car" speeds up, you speed up, etc. It would be like tailing a friend to a destination that you don't know the way to.) If for some reason you start to lose the "phantom car" (such as by braking when you see a group of children at play), the "phantom car" would simply slow down or stop to where you could catch it again, and it would adapt, recalculating everything.

The system could conceivably hook into the computer network responsible for controlling the traffic lights. Some example scenarios of its use:

- Due to how traffic light timings are changed throughout the day/year, it might happen that route A is fastest in the morning, but route B is fastest at night.

- Perhaps by driving 2 MPH under the speed limit on a certain route, it would eliminate the need to actually stop at intersections because your car would be perfectly timed to hit the green lights. Save gas, and no more annoying starts/stops.

- Perhaps by accelerating just a tiny bit faster when a particular light turns green, you could avoid a red light down the road. It would tell you exactly what speed to match and when, ensuring that you get green lights all the way (or as much as possible).

- Since it knows when the lights will change, the system would let you know whether or not you could safely make a green/yellow light, or if you should slow down in advance. (Or perhaps by going 2MPH over the speed limit, you'll beat the light! Shhhh!) Everything could be customizable to suit the driver. (An elderly person might feel more comfortable driving slower, for instance.)

These are but a few examples. Of course, much care would have to be taken to ensure that the product wasn't a hazard to other drivers, etc, but if those issues could be worked out, it'd be great. I wish every day that I had one of these.
-- Uberminky, Jun 17 2002

I experienced the M25 around London on Saturday. They advise not changing lanes if possible, and display variable speed limits on overhead light systems, in order to get the body of traffic slowing down at some areas so that it doesn't bottle up in places where there is a need to change lanes and move on/off the motorway. The theory is sound, but in practice it really doesn't seem to be working.
-- sappho, Jun 17 2002


I be afraid that the people around me were paying more attention to their ghost than to traffic signals.
-- phoenix, Jun 17 2002


If that bit of the M5 between 13 and 16 was really busy, it would tell you to use the A38 instead. Of course, it would also tell everyone else to use the A38.
-- angel, Jun 17 2002



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