Many rules govern drivers on the streets and highways. The most common one is the speed limit. The speed limit controls how fast a car may go. On streets in the city, the speed limit is usually 25 or 35 miles per hour. On the highways between cities, the speed limit is usually 55 miles per hour. When people drive faster than the speed limit, a policeman can stop them. The policeman gives them pieces of paper which call traffic tickets. Traffic tickets tell the drivers how much they must pay. When drivers receive too many tickets, they probably cannot drive for a while. The rush hour is when people are going to or returning from work. At rush hours there are many cars on the streets and traffic moves very slowly. Nearly al big cities have rush hours and traffic jams. Drivers do not get tickets very often for speeding during the rush hour because they cannot drive fast.