Driving in a Hurry
Naturally, if you are in a hurry to go somewhere, you are more likely to drive faster and break the speed limit. However, because you will have to come to a stop at nearly every traffic light on the route, you will only wear out your brakes.
The problem is that stoplights are set up in such a manner that drivers who stick to the speed limit can hit green lights more frequently. If you only follow the speed limit and drive slowly, you will miss fewer red lights and be more likely to arrive on time.