Some people think they have an answer to the troubles of automobile crowding and dirty air in large cities. Their answer is the bicycle, or 'bike.' In a great many cities, hundreds of people ride bicycles to work every day. In New York City, some bike riders have even formed a group called Bike for a Better City. They claim that if more people rode bicycles to work there would be fewer automobiles in the downtown section of the city and therefore less dirty air from car engines. For several years this group has been trying to get the city government to help bicycle riders: For example, they want the city to draw bicycle lanes on some of the main streets, because when bike riders must use the same lanes as cars, there are accidents. Bike for a Better City feels that if there were special lanes more people would use bikes. But no bicycle lanes have been drawn. Not everyone thinks it is a good idea--they say it will slow traffic. Some store owners on the main streets say that if there is less traffic, they will have less business. And most people live too far from downtown to travel by bike. The city government has not yet decided what to do. It wants to keep everyone happy. Only on weekends, Central Park is closed to cars, and the roads may be used by bicycles only. But Bike for a Better City says that this is not enough and keeps fighting to get bicycle lanes downtown. According to the passage, bicycles ______.