"Medical Exemptions" are also a standard right in the State of Texas for motorcycles & even bicyclists. Through Texas's motorcycle helmet law (bicycle helmet laws from city ordinances), it is only required for those 21 years old or younger to wear a helmet. However, a medical exemption,[133][134][135][136][137] written by a certified licensed medical physician or licensed chiropractor, which exempts one from wearing a helmet, can be used for bicyclists if helmets are required.
While the first functional battery was developed in the year 1800 by Italian physicist Alessandro Volta, a practical battery would not be seen for several decades yet. By the end of the 19th century, practical and portable batteries were more widely available, this finally freeing the electric motor to be used in a wide new array of applications. It might come as a surprise, but the electric motor, battery, and a bicycle were first paired as far back as the 1890s. It would be approximately 100 years later that electric bicycle development finally entered the mainstream, but the technology and concept behind the electric bike were all in place generations ago.
Motor-driven cycles may be operated on the roadway without registration, but the operator must have a driver's license.[85] The cycle may not be operated on any sidewalk, limited access highway or turnpike. If the maximum speed of the cycle is less than the speed limit of the road, the cycle must operate in the right hand lane available for traffic or upon a usable shoulder on the right side of the road unless the operator is making a left turn.

Electric bicycle fits under the definition of "moped" under Kentucky law. You don't need tag or insurance, but you need a driver's license. "Moped" means either a motorized bicycle whose frame design may include one (1) or more horizontal crossbars supporting a fuel tank so long as it also has pedals, or a motorized bicycle with a step-through type frame which may or may not have pedals rated no more than two (2) brake horsepower, a cylinder capacity not exceeding fifty (50) cubic centimeters, an automatic transmission not requiring clutching or shifting by the operator after the drive system is engaged, and capable of a maximum speed of not more than thirty (30) miles per hour[43][44] Helmets are required.
There are individuals who claim to have lost considerable amounts of weight by using an electric bike.[62] A recent prospective cohort study however found that people using e-bikes have a higher BMI.[63] By making the biking terrain less of an issue, people who wouldn't otherwise consider biking can use the electric assistance when needed and otherwise pedal as they are able.[64] This means people of lower fitness levels or who haven't cycled in many years can start enjoying the many health benefits E-bikes have to offer. [1]