And while it would appear that light rail can transport more people per day, the opposite is true. A single light-rail car can hold about 150 people, and in most cities three can be strung together in a train holding 450. By comparison, the biggest buses hold only a few more than 100 people. For safety reasons, however, most light-rail lines can support only about 20 trains an hour in each direction, while city streets can serve more than 160 buses per hour, giving the buses a huge capacity advantage. Where an expensive light-rail line can move about 9,000 people per hour, an inexpensive bus route can move nearly twice that many on city streets and many times more on a freeway lane.