A motorized bicycle shall not be operated by any person under sixteen years of age, nor at a speed in excess of twenty-five miles per hour, upon any public highway, private way laid out under authority of statute, way dedicated to public use, or way under the control of park commissioners or body having like powers, within the commonwealth.[99] A motorized bicycle shall not be operated on any way by any person not possessing a valid driver's license or learner's permit. Every person operating a motorized bicycle upon a way shall have the right to use all public ways in the commonwealth except limited access or express state highways where signs specifically prohibiting bicycles have been posted, and shall be subject to the traffic laws and regulations of the commonwealth and the regulations contained in this section, except that the motorized bicycle operator may keep to the right when passing a motor vehicle which is moving in the travel lane of the way, and the motorized bicycle operator shall signal by either hand his intention to stop or turn. Motorized bicycles may be operated on bicycle lanes adjacent to the various ways, but shall be excluded from off-street recreational bicycle paths. Every person operating a motorized bicycle or riding as a passenger on a motorized bicycle shall wear protective headgear conforming with such minimum standards of construction and performance as the registrar may prescribe, and no person operating a motorized bicycle shall permit any other person to ride a passenger on such motorized bicycle unless such passenger is wearing such protective headgear.
Electric bikes are here in a big way. Liberated from some of the normal constraints of standard bike design like weight and gearing, e-bike design has exploded; if you can imagine it, someone has built it. From cargo bikes to city bikes, messenger bikes to mountain bikes, road bikes, folding bikes, and even beach cruisers, there is something for everyone. The beauty of e-bikes is that they make the joy of cycling accessible to so many people in so many ways.

Every person riding a bicycle, electric personal assistive mobility device, electric power-assisted bicycle, moped, or an animal or driving an animal on a highway shall be subject to the provisions of this chapter and shall have all of the rights and duties applicable to the driver of a vehicle, unless the context of the provision clearly indicates otherwise.