Massachusetts

Motorcycle:

“any motor vehicle having a seat or saddle for the use of the rider and designed to travel on not more than three wheels in contact with the ground, including any bicycle with a motor or driving wheel attached, except a tractor or a motor vehicle designed for the carrying of golf clubs and not more than four persons, an industrial three-wheel truck, a motor vehicle on which the operator and passenger ride within an enclosed cab, or a motorized bicycle.”

Motorized Bicycle:

“a pedal bicycle which has a helper motor, or a non-pedal bicycle which has a motor, with a cylinder capacity not exceeding fifty cubic centimeters, an automatic transmission, and which is capable of a maximum speed of no more than thirty miles per hour.”