I ride my bike on an asphalt path around an air park here. The path is 7 feet wide with a lane in each direction. There were a few people riding those trikkes on the path. The movement necessary to make them go has then taking up both lanes in a side to side movement. My complaint about them, and it may be just these riders, they had ipods with ear plugs, I could not get their attention to pass them. I finally went out into the street to get around them. They seem to need a lot of room going side to side.