I was checking out Texas laws about e-bikes (side project, long story) and found this:  
Sec. 551.106 REGULATION OF ELECTRIC BICYCLES. (a) The department or a local authority may not prohibit the use of an electric bicycle on a highway that is primarily used by motor vehicles. The department or a local authority may prohibit the use of an electric bicycle on a highway that is primarily used by pedestrians.
 
I can make a little electric motor to friction drive a wheel and powered by a small battery. As long as the wheel turns by electric power regardless of whether it does anything useful then it's an electric bicycle and can't be banned from any street or highway in Texas. If we get stopped on FM 455 in Anna we can show we are riding an electric bicycle and quote Sec 551.106 at them.
 
Opus