According to Utah Code 41-6a-102 (17) an electric assisted bicycle is equipped with an electric motor with a power output of not more than 750 watts and is not capable of further assistance at a speed of more than 20 MPH, or at 28 MPH while pedaling and using a speedometer. New laws specifically exclude electric pedal-assisted bicycles as "motorized vehicles" and bicycles are permitted on all state land (but not necessarily on Indian Reservations, nor restrictive municipalities, such as in Park City Code 10-1-4.5 2) if the motor is not more than 750 Watts, and the assistance shuts off at 20 mph (Utah Traffic Code 53-3-202-17-a 1). E-bikes sold in Utah are required to have a sticker that details the performance capacity. Children under 14 can operate an electric bicycle if accompanied by a parent/guardian, but children under 8 may not. (Utah code 41-6a-1115.5) No license, registration, or insurance is required by the State but some municipalities may require these measures (Salt Lake City and Provo require registration).
Electric motorized bicycles can be power-on-demand, where the motor is activated by a handlebar mounted throttle, and/or a pedelec (from pedal electric), also known as electric assist, where the electric motor is regulated by pedaling. These have a sensor to detect the pedaling speed, the pedaling force, or both. An electronic controller provides assistance as a function of the sensor inputs, the vehicle speed and the required force. Most controllers also provide for manual adjustment.

"Electric power-assisted bicycle" means a vehicle that travels on not more than three wheels in contact with the ground and is equipped with (i) pedals that allow propulsion by human power and (ii) an electric motor with an input of no more than 1,000 watts that reduces the pedal effort required of the rider. For the purposes of Chapter 8 of this title, an electric power-assisted bicycle shall be a vehicle when operated on a highway.[65]

In Nova Scotia power-assisted bicycles are classified similarly to standard pedal bicycles. The Nova Scotia Motor Vehicle Act defines a power-assisted bicycle as a bicycle with an electric motor of 500 watts or less, with two wheels (one of which is at least 350 mm) or four wheels (two of which are at least 350mm). PABs are permitted on the road in the province of Nova Scotia as long as you wear an approved bicycle helmet with the chinstrap engaged. They do not have to meet the conditions defined within the Canadian Motor Vehicle Safety Regulations for a motorcycle (they are not classed as "motor vehicles"), but they do have to comply with federal regulations that define Power Assisted Bicycles.

Oregon Law (ORS 801.258) defines an electric assisted bicycle as an electric motor-driven vehicle equipped with operable pedals, a seat or saddle for the rider, no more than three wheels in contact during travel. In addition, the vehicle must be equipped with an electric motor that is capable of applying a power output of no greater than 1,000 watts, and that is incapable of propelling the vehicle at a speed no greater than 20 miles per hour on level ground.[54]
The basic shape and configuration of a typical upright or "safety bicycle", has changed little since the first chain-driven model was developed around 1885.[7][8][9] However, many details have been improved, especially since the advent of modern materials and computer-aided design. These have allowed for a proliferation of specialized designs for many types of cycling.
Torque sensors and power controls were developed in the late 1990s. For example, Takada Yutky of Japan filed a patent in 1997 for such a device. In 1992 Vector Services Limited offered and sold an e-bike dubbed Zike.[9] The bicycle included NiCd batteries that were built into a frame member and included an 850 g permanent-magnet motor. Despite the Zike, in 1992 hardly any commercial e-bikes were available.
The Class 3 Aventon Pace 500 urban e-bike has five levels of pedal assist and tops out at 28 mph. But the Pace has something not found on a lot of modern e-bikes. In addition to pedal power, it also has a throttle—in the case of the Pace, a small thumb paddle on the left side of the handlebar next to the control unit that holds at a steady 20 mph, no pedaling required. The bike itself has an aluminum frame, a swept-back handlebar, ergo grips, a sturdy kickstand, hydraulic disc brakes, 8-speed Shimano Altus shifting and gearing, 27.5x2.2-inch Kenda e-bike-rated tires, a saddle the size of Texas, and good ol’ classic city/commuter-bike geometry. It doesn’t come equipped with fenders or a rear rack, but you can add them. Power comes in the form of a 500-watt rear-hub motor, a semi-integrated battery on the down tube (with a range of up to 50 miles), and a backlit display unit mounted on the stem. 

Indian law requires that all electric vehicles have ARAI[50] approval. Vehicles with below 250W and speed less than 30 km/h, do not require certification- hence not following full testing process, but needs to get exemption report from ARAI. Whereas more powerful vehicles need to go through a full testing process following CMVR rules. This can take time and cost money but assures safe and reliable design for Electric Vehicles. These regulations are not promulgated by the Regional Transport offices, and riders are not required to obtain a licence to drive, to carry insurance, or to wear a helmet.
The federal Consumer Product Safety Act defines a "low speed electric bicycle" as a two or three wheeled vehicle with fully operable pedals, a top speed when powered solely by the motor under 20 mph (32 km/h) and an electric motor that produces less than 750 W (1.01 hp). The Act authorizes the Consumer Product Safety Commission to protect people who ride low-speed electric vehicles by issuing necessary safety regulations.[63] The rules for e-bikes on public roads, sidewalks, and pathways are under state jurisdiction, and vary.