"Bicycles" and "Electric Bicycles" are legally defined in the Texas Transportation Code Title 7, Chapter 551 entitled "Operation of Bicycles, Mopeds, and Play Vehicles" in Subchapter A, B, C, and D.[131] Under Chapter 541.201 (24), "Electric bicycle" means a bicycle that is (A) designed to be propelled by an electric motor, exclusively or in combination with the application of human power, (B) cannot attain a speed of more than 20 miles per hour without the application of human power, and (C) does not exceed a weight of 100 pounds. The department or a local authority may not prohibit the use of an electric bicycle on a highway[132] that is used primarily by motor vehicles. The department or a local authority may prohibit the use of an electric bicycle on a highway used primarily by pedestrians.
Bicycle shall mean (1) every device propelled solely by human power, upon which any person may ride, and having two tandem wheels either of which is more than fourteen inches in diameter or (2) a device with two or three wheels, fully operative pedals for propulsion by human power, and an electric motor with a capacity not exceeding seven hundred fifty watts which produces no more than one brake horsepower and is capable of propelling the bicycle at a maximum design speed of no more than twenty miles per hour on level ground.
From the beginning and still today, bicycles have been and are employed for many uses. In a utilitarian way, bicycles are used for transportation, bicycle commuting, and utility cycling. It can be used as a 'work horse', used by mail carriers, paramedics, police, messengers, and general delivery services. Military uses of bicycles include communications, reconnaissance, troop movement, supply of provisions, and patrol. See also: bicycle infantry.
However, Emu sells a little foldable number if that's your bag. The Emu Crossbar is for  town commuters that require a sweet ride that's backed up by solid Shimano Nexus hub gears and Tektro brakes, which are adequate if not the best on the market. Riding is smooth and easy, with the crank moving sensor doing its best to iron out any gaps in power delivery.
If you are a person who enjoys riding a bike casually at a typical bike path speed (10-15mph), and you like the idea of an ebike push up a hill, against the wind or to relieving a sore knee, then your market for a fully legally defined ebike is very broad and your practical use only has a few limitations. Most ebikes will meet your needs and expectation. I would estimate that 85% of the electric bikes on the market are 100% compliant meeting the federal definition. I encourage you to take the plunge and get a good quality ebike and ride more with assist. Do so with the confidence that electric bikes are here to stay. Coexisting with pedestrians and other cyclist will become a normal part of cycling life.

The last 8 months we've been wrapping up some long duration testing of Statorade across different hub motor lines and performing experiments confirming its long term stability. These results have us pumped to introduce this motor cooling solution beyond DIY'ers and into wider markets. As an example, have a look at the video we below showing the effect this has on a small direct drive folding bike motor.
But the whole is also influenced by the sensory systems which are very different from model to model. E.g. A typical 2013 Panasonic system requires pedalling for optimal support (55/minute?) and has both a pedalling frequency and a speed sensor. You don't get much assistance if you pedal very slowly or very fast. Typically, a rear motor has a force sensor, i.e. you get lots of support fast when you start pedalling in a low gear, i.e. it will "feel" your need for assistance.

The Domane+ e-road bike is the electric version of Trek’s popular Domane. It’s designed for riders who appreciate that bike’s reliable comfort and IsoSpeed technology but want the added fun and function of e-assist. It’s also the ideal companion for anyone coming back from injury, slower riders who want to mix it up with a speedy group, and couples with different fitness levels. A Bosch Performance Line Speed motor provides a very welcome 28 mph of pedal assist, and the 500Wh Powertube battery sleekly integrates into the down tube. Also integrated: front and rear lights, which are powered by the battery—no charging required.

Simple, convenient, cheap, and economical—bicycles are one of the world's favorite forms of transportation. But they're not for everyone. They can be hard to pedal up and down hills or with heavy loads, and elderly or disabled people may find them impossible to manage. In the last few years, a new generation of electric bicycles has begun to revolutionize our idea of environmentally friendly transportation. These new cycles have all the convenience of cars with all the simple economy of ordinary cycles. Let's take a closer look at how they work.