response: I'm afraid I have no idea, exactly, but they're the primary form of transportation in some parts of the world.
original_response: I'd imagine the vast majority. They are the principal means of transportation in much of Asia.
history: Man, I just got back from a bike ride earlier today. Has to be one of my favorite ways to supersize Well, that's good. So, do you bike mostly for exercise, or also for recreation or sport? It's for exercise, but mostly for recreation. I predominately road bike on prairie paths. Did you know there are around 1 billion bicycles worldwide? That's a lot of bicycles! I wonder how many of those people are biking as their primary modes of transportation.
knowledge: They are the principal means of transportation in many parts of the world.