Traffic in most American cities is a problem, especially during the rush hours when many people are going to or returning from work. Consequently, there are traffic reports on the radio throughout the day, and there are many articles about traffic issues and traffic accidents in the newspaper. Traffic issues, road building, repairs, and the quality of public transportation are so important to the general public that they are often brought up during political campaigns. Expanding public transportation and encouraging car pools are two methods often discussed to improve traffic congestion. Many major cities are beginning to designate one lane of their major highways for only car pool traffic during rush hours, and special car pool parking lots are being built outside major cities. In addition, people are being encouraged to use public transportation, such as buses and underground trains whenever possible. Many cities offer special discount tickets on public transportation for commuters who use this form of transportation regularly.
【題組】Public transportation has encouraged ______.
(A) car pools (B) rush hours (C) discount tickets (D) traffic reports