Ian Ayres encourages us to rethink how we cross the road:
One often sees pedestrians approach an intersection, press the button, and then immediately cross the street, before the crossing light changes. The pedestrian probably reasons a) "I have a right to press the button"; and b) having pushed it, I now see I can walk without inconveniencing anyone because there aren’t any cars coming. The problem with this reasoning is that just because you have the right to press the crosswalk button doesn’t mean that it is considerate for you to do so. … Pressing the button while having a conditional intention to cross the street early is inconsiderate because cars often then have to wait for a crossing light when there are no longer any crossing pedestrians to protect. It wastes gas.
The Dish 