A tricycle is a three-wheeled vehicle, usually powered by pedaling. Most people picture the small tricycles that young children ride before they learn to balance on a regular bicycle. These typically have one wheel in front for steering and two wheels in back for stability.

Because tricycles don't tip over as easily as bicycles can, they let a three-year-old experience the thrill of pedaling and steering without needing training wheels or a parent running alongside. The child can focus entirely on making the pedals go round and choosing where to steer.

Tricycles also serve many adult purposes. Adults use larger versions called recumbent tricycles, where the rider sits in a reclined position. These adult tricycles work well for people with balance difficulties or anyone who wants a stable ride. You might also see cargo tricycles used for deliveries in crowded city streets, ice cream vendors pedaling tricycles with freezers attached, or even powered tricycles serving as taxis in some countries.