Canada, Europe and the United States have all passed legislation regarding electric bicycles and categorize them separately from mopeds and motorcycles. In 2001, the U. S. Congress passed Public Law 107-319 which exempts electric bikes under 750 watts and limited to 20 mph (with operating pedals) from the legal definition of a motor vehicle.
Some states have passed their own laws, but states cannot constitutionally pass legislation that reduces or eliminates Federal laws. An electric bike is legally a bicycle, so you can use it wherever and however you're able to use a standard bicycle. But additional laws governing the operation and safety of electric bikes may be extended by state or local governments. In most states, no license, insurance or registration is required. If you are unfamiliar with local electric bike laws, consider this:
1.) Police don't normally know the specific rules pertaining to electric bikes.
2.) Police often expect electric bike and scooter riders to wear a bicycle helmet.
3.) Most electric bikes look like ordinary bicycles to the casual observer.
* LOCAL LAWS: Be sure you understand all state and local laws regarding the operation and safety of your electric bike or scooter. It is the sole responsibility of the owner to research all applicable rules and regulations, which can be obtained from your local police or DMV.
In most states, electric scooters fall into a "gray area". Because they don't have operating pedals, they're not considered electric bikes. But in most cases they don't classify as mopeds either, since they're rated by watts - not CCs. Most states have not created separate laws for electric scooters, but be sure to check with your local police or DMV. In 2005, California incorporated the following rules which we've provided for your reference:
A driver's license or learners permit is required to drive an electric scooter.
No insurance, registration or license plates are required.
Driver must wear a bicycle helmet.
Driver shall not operate motorized scooter in excesses of 15 mph.
Driver shall not operate on public road with a speed limit of 25 mph or more, unless it is operated in a bike lane.
Driver to operate on right side of the roadway and next to the curb when feasible. When intending to move left at an intersection, they must walk their scooter in a crosswalk when crossing roadway.
Driver must operate in a designated bike lane when one is available.
Driver must not ride on any sidewalk except to leave or enter adjacent property.
Driver shall not leave scooter on path or sidewalk.
Driver shall not hitch scooter onto another vehicle in motion.
Driver shall not have passengers.
Driver can be on bike path or trail unless prohibited by local ordinance.
Driver must have at least one hand on handlebars.
Equipment requirements during hours of darkness:
White headlight to the front visible from 300 feet both to the front and sides.
A red reflector on the rear of the device, visible from 500 feet.
White or yellow reflector on each side visible from the front and rear of the device from 200 feet.
A white lamp or white lamp combination, attached to the operator and visible from 300 feet in front and from the sides of the motorized scooter.
Handlebars must not exceed shoulders of the rider.
Scooter must have an engine/motor kill switch that activates when released or when the brakes are applied.
Scooter must have a working brake.
* The electric scooter laws listed above are applicable to California residents only, but have been provided for reference purposes.
Canada, Europe and the United States have all passed legislation regarding electric bicycles and categorize them separately from mopeds and motorcycles. In 2001, the U. S. Congress passed Public Law 107-319 which exempts electric bikes under 750 watts and limited to 20 mph (with operating pedals) from the legal definition of a motor vehicle. 
