填空题
Many people in Los Angeles drive long distances back and forth to work on freeways. Free ways are wide highways without traffic lights. Some have as many as six lanes traveling in both directions. However, the freeways get very crowded during morning and afternoon rush hour. If a large vehicle breaks down or overturns, it blocks the lanes and the traffic may become jammed for hours. Traffic is also slow where one freeway meets another. In recent years, public officials have tried to reduce the number of cars on the freeways by asking people to share their cars. If several people ride to work in the same car, one lane of the freeway is reserved for them. On their way to work, they listen to traffic reports on their car radios.
What are freeways