according to a show I recently saw on tv, gasoline powered bicycles often produce more harmful emissions than cars - at least in china, where they are popular. acording to this show there are several hundred thousand in one of the larger cities alone (forget which).
Strange, in all of China I have seen
ONE petrol powered bicycle. I even took a picture of it. It looked like an early early Davidson (the ones from the 1800's). I havn't even seen many petrol powered mopeds; I have, possibly, seen four or five. I am interested in what city they did this study.
Most of what is seen here is (of course, bicycles but there are a lot of laws trying to discourage thier use). The next most popular is the electric moped (I do not consider these to be electric bicycles due to weight and thet they are not intended to be pedaled; most people remove the pedals). Then electric scooters. These look like motorscooters but have electric drive, then petrol powered scooters; and finally, motorcycles followed by private cars.
A lot of the petrol scooters are two stroke, so they do polute a lot. However, even the electric mopeds are exempt from the anti bicycle laws; thus making them very popular.