Nebraska defines a Moped as "a bicycle with fully operative pedals for propulsion by human power, an automatic transmission, and a motor with a cylinder capacity not exceeding fifty cubic centimeters which produces no more than two brake horsepower and is capable of propelling the bicycle at a maximum design speed of no more than thirty miles per hour on level ground."[69]
Oklahoma the following restrictions on the operation of Electric-Assisted Bicycle in 47 O.S. 11-805.2 [123] as follows: 1. Possess a Class A, B, C or D license, but shall be exempt from a motorcycle endorsement; 2. Not be subject to motor vehicle liability insurance requirements only as they pertain to the operation of electric-assisted bicycles; 3. Be authorized to operate an electric-assisted bicycle wherever bicycles are authorized to be operated; 4. Be prohibited from operating an electric-assisted bicycle wherever bicycles are prohibited from operating; and 5. Wear a properly fitted and fastened bicycle helmet which meets the standards of the American National Standards Institute or the Snell Memorial Foundation Standards for protective headgear for use in bicycling, provided such operator is eighteen (18) years of age or less.
Electric bikes are becoming a convenient and fun way to commute around a city, but they can be pricey. The average e-bike can cost $3,000, with some models getting up to $5,000 or more. But these prices are dropping, as new models come onto the market — and if you don’t mind giving up some of the glossier, high-tech features like embedded digital displays, retractable cable locks, and and theft tracking and recovery, you can find a really good quality e-bike for under $1,500.
Are there any guidelines you could give on what is legal in Federal Parks that have duel use pedestrian and bike paths. I was recently told that E bikes are not allowed on a Federal trail even though much faster 10 and 20 speed bicycles are common. I also stated that I have a disability which prevents me from walking or biking very far but was still told my bike was not allowed. I should also add that my bike has a top speed of about 15 and is 250 watts.

From all the Chinese brands that have come and disappeared, Onway is still standing strong. That means that they have sold enough bikes, and they have been tried and tested enough for customers to know what to expect. So, what can you expect from this Onway bike? Well, for a very affordable price, you will get anything you realistically need in an e-bike – multi-purpose tires for various terrains, LCD display, LED headlights, taillights, a kickstand… Overall build quality and quality of the parts is above average, but there are some things that you will need to change, and seat should be the first on the list. Customer support is not that great, but if you decide to purchase this bike you will get a fun bike, for affordable price that you will be able to assemble and ride in no time.
The federal law will not prohibit a motor vehicle label and additional restrictions given by the state. States will typically define e-mopeds in the 1000W range (1.5 hp) and speeds attainable to 30mph, and include a few requirements such as a helmet, eye protection, and a driver’s license. States may also require title, registration, and insurance for mopeds.
Photo: Zap Electric's power-assist kit turns a conventional bike into an electric one. There's a bolt-on DC electric motor (weighing just over 3kg or 7lb) just above the back wheel, behind the police officer's foot, pressing against the tire and driving it by simple friction. The motor's powered by a compact lead-acid battery (weighing about 5.5 kg or 12 lb) inside a protective nylon bag. This kit adds quite bit of weight to the bike, but gives extra range and speed when needed. Photo taken in Santa Rosa, California by Rick Tang courtesy of US DOE/NREL.
Attitudes to electric bikes have changed in recent years. For a long time they were seen by cyclists as 'cheating' and by non-cyclists as being just like a bike, but uglier and far more expensive. This new breed of best-in-class electric bikes feel more natural, look more normal, and people are coming around to the idea that a ride with the convenience of a bike but without all the sweat and effort is a Very Good Thing. 
Electric-assisted bicycles are treated as human-powered bicycles, while bicycles capable of propulsion by electric power alone face additional registration and regulatory requirements as mopeds. Requirements include electric power generation by a motor that cannot be easily modified, along with a power assist mechanism that operates safely and smoothly. In December 2008, The assist ratio was updated as follow: