As of May 19, 2009, Nevada amended its state transportation laws to explicitly permit electric bicycles to use any "trail or pedestrian walkway" intended for use with bicycles and constructed with federal funding, and otherwise generally permits electric bicycles to be operated in cases where a regular bicycle could be. An electric bicycle is defined as a two- or three-wheeled vehicle with fully operable pedals with an electric motor producing up to 1 gross brake horsepower and up to 750 watts final output, and with a maximum speed of up to 20 miles per hour on flat ground with a 170-pound rider when powered only by that engine.[106]
Electric powered bicycles slower than 20 km/h without pedaling are legally recognized as a non-mechanically operated vehicle in China.[32] According to "TECHNOLOGY WATCH", this should help promote its widespread use.[33] Electric bicycles were banned in some areas of Beijing from August 2002 to January 2006 due to concerns over environmental, safety and city image issues. Beijing has re-allowed use of approved electric bicycles as of January 4, 2006.[34] Some cities in China still ban electric bikes. 

Hub motors are sold as either geared or direct drive: Geared hubs are preferred for hill climbing ability and zero drag when coasting, while DD hubs are more durable and suitable for high speed. Extreme hill climbing and high torque applications (fatbikes, hauling cargo, popping wheelies) usually requires a mid drive, which is covered in the motor section below. Ebike battery packs from the listed suppliers are generally compatible with kits from any supplier, at worst you may need a different connector, which can be easily replaced. You probably want a battery pack that is 36, 48, or 52 volts, depending on whether you prefer lower price and longer range or a higher topspeed. DIY lipo battery packs can be built cheaply but doing so can be a fire hazard so actual packs are recommended. All hub motors above 24 V should be installed with torque arms for safety.
At just 36V and 5.2 Ah, the battery is not designed for long distance travel. GOTRAX claims the Shift S1 has a range of up to 15 miles (25 km), though that’s only with a lower pedal assist level. If you’re going full throttle, 10 miles (15 km) is a better estimate. But with a battery this small, you could easily charge it at your desk or in the corner of the classroom – lengthening your effective range.

Electric Bicycles are defined by the California Vehicle Code [32][33]. In summary, electric bicycles are to be operated like conventional bicycles in California. There are several exceptions to this. A person must be at least 16 years old, and anyone riding an electric bicycle must wear a bicycle helmet. The e-bikes must have an electric motor that has a power output less than 1,000 watts, is incapable of propelling the device at a speed of more than 20 miles per hour on level ground, is incapable of further increasing the speed of the device when human power is used to propel the motorized bicycle faster than 20 miles per hour, operates in a manner so that the electric motor is disengaged or ceases to function when the brakes are applied, or operates in a manner such that the motor is engaged through a switch or mechanism that, when released, will cause the electric motor to disengage or cease to function.

Some power-on-demand only e-bikes can hardly be confused with, let alone categorised as, bicycles. For example, the Noped is a term used by the Ministry of Transportation of Ontario for e-bikes which do not have pedals or in which the pedals have been removed from their motorised bicycle. These are better categorised as electric mopeds or electric motorcycles.
eBikes are a key part of solution to reduce carbon emissions globally. The Zero-emission part of the eBike discussion is based on re-charging the battery on a daily basis from a Sustainable Electrical Source such as solar, wind, hydro, geo thermal, etc.  The fact is today part of the eBike Battery charge is coming from Power Plants that are running …
Seth Miller said he founded the company after his first electric bike was stolen from where it was parked in front of the midtown office building where he worked. The company that manufactured the bike had disbanded, so he started researching different suppliers. He soon discovered that a majority of the e-bikes sold in the US are just cobbled together from a variety of off-the-shelf Chinese-made parts found in a catalog. It sounded simple, so Miller figured he’d try it himself.
The aluminum, step-through eJoy is the happy medium between traditional-looking townies that don’t transport much more than the rider and often cumbersome cargo models that are sometimes a challenge to store. With 26-inch wheels, full fenders, a Shimano Alivio nine-speed drivetrain and disc brakes, a wheelbase similar to the average townie, and a big, comfy seat, it has the appearance of a practical everyday cruiser. But its oversize rear rack, silent Bosch Active Line motor, heavy-duty head tube with front-tray mounts (the tray is an add-on), integrated Supernova E3 lights, and roll-over-anything balloon tires hurtle it into hmm-this-could-actually-replace-my-car status. It’s one of the quietest, most convenient, most stylish, and easiest-to-operate e-bikes available.
Experiments done in Uganda, Tanzania, and Sri Lanka on hundreds of households have shown that a bicycle can increase a poor family's income as much as 35%.[69][better source needed][70][71] Transport, if analyzed for the cost-benefit analysis for rural poverty alleviation, has given one of the best returns in this regard. For example, road investments in India were a staggering 3–10 times more effective than almost all other investments and subsidies in rural economy in the decade of the 1990s. What a road does at a macro level to increase transport, the bicycle supports at the micro level. The bicycle, in that sense, can be an important poverty-eradication tool in poor nations.
I purchased version 2.0 of this device and the manufacturer has been listening to comments from users and making running changes such as the three speeds and the rear suspension. I am an XL size user (6'2", 230lbs) and recently returned from a 26 day cruise around Europe. I rode this little scooter on cobblestones, miles and miles through the Vatican, inside ancient cities and all over the streets of San Juan upon our return stateside. There was only one time it was less than ideal and that was going uphill, on slick tile that was wet from a drizzle. It still make it, just had to lean way forward to get weight on the front wheel.