Those who drive with fuel effeciency in mind will often do all sorts of seemingly strange things in relation to red lights. The most classic one of coming to a complete stop and then creeping forward inches at a time is not particularly fuel efficient, but there are a whole bunch of other similar behaviors that are.
You see I care about getting good gas mileage. I drive a Geo Metro. Now that little thing is already rated for over 40 miles to the gallon, but I shoot for 50, and I often get it.
When I am stopping at a familiar stop light facing downhill I will usually stop nearly completely quite far from the light, then I will slowly inch forward, finally letting the brake off completely at the right time. When the light finally turns green I will be going 10 or 15 miles per hour, all of which was gained from rolling downhill. Not only do I get past the light quicker I also get to skip first gear entirely.
At other lights I will spot the red light as far off as possible. I have a general rule about red lights. If a light is red in front of me, and I know I am going to have to stop for it, then I am in neutral and rolling. If I am still going to roll right up to it then I will keep reducing speed in an effort to hit the light while still moving. Nothing uses more gas than getting your vehicle moving from a complete stop. I own a 26 foot motor home that gets 6 miles per gallon on the highway. I shudder to even think about how much gas it uses getting up to speed from a complete stop.
If I am truly forced to stop at a light then I will often stop a good car length away from the car in front of me (traffic permitting, I am not going to force people to be stuck in the previous intersection). That gives me just that little bit of extra difference to take off at the exact same time as the car in front of me. I can also more safely use a normal fuel efficient acceleration profile, without running into the rear end of light footed drivers. Groups of people coming off a light tend to accelerate quite slowly at first, that extra car length allows me to mostly ignore that phenomena.