Human-powered

Human-powered transport, a form of sustainable transport, is the transport of people or goods using human muscle-power, in the form of walking,[16] running, and swimming. Technology has allowed machines to improve the energy efficiency of human mobility on relatively smooth terrain.[17] Human-powered transport remains popular for reasons of cost-saving, leisure, physical exercise, and environmentalism;[18] it is sometimes the only type available, especially in underdeveloped or inaccessible regions.

Although humans are able to walk without infrastructure, the accessibility can be enhanced through the use of roads, sidewalks, and shared-use paths, especially when using the human power with vehicles, such as bicycles, inline skates, and wheelchairs.[19] Human-powered vehicles have been developed for difficult environments, such as snow and water, by watercraft rowing and skiing;[20][21] even the air can be flown through with human-powered aircraft.[22] Personal transporters, a form of hybrid human-electric powered vehicle, have emerged in the 21st century as a form of multi-model urban transport.[23]