electric or internal combustion motorcycles (which also include scooters) are also an option. internal combustion motorcycles do create some degree of local air pollution however. that said, the degree of local air pollution varies considerably depending on which fuel (i.e. gasoline, lpg, cng/biogas, hydrogen) is injected to the internal combustion engine. this fuel can be freely chosen, and existing motorcycle engine can be converted to run on these. hydrogen for instance is described as being "near-emissionless" when burned in a internal combustion engine.