It is easy to find a bright yellow bike on a street corner in some cities. You can ride a bike and go anywhere you want. But wait—isn't it stealing？ No one yells（叫喊）because this ride that you paid 1 yuan is just fine with the city.
The idea began in Portland, Oregon（俄勒冈州波特兰市）in the U.S. in 1994． People saw a need for free transportation（交通）, and they wanted to help control pollution（控制污 染）. So, in order to（为了）get people out of their cars onto pollution—free bikes, they started the Yellow Bike Project.
The public bikes are painted bright yellow and put all over the city. People can freely ride the yellow bikes to work, to school…Then they can leave the bike for the next rider after riding. Most people obey the rules today.
