grwalker said:
Not true. Just google it (http://en.wikipedia.org/wiki/Electric_bicycle_laws#Defined_2) and check out the Wikipedia article. It seems to cover Federal and state regs quite well. The bottom line is it must not be able to "power" above 20mph to be street legal as a "Bicycle" in the US and Canada. Otherwise it is a powered vehicle with all the helmet, insurance and licensing rules applied.
The "federal law" people keep erroneously referring to as a country-wide limitation is only a CPSC regulation, which simply defines what a "low power electric bicycle" is in reference to what manufacturers are allowed to call such things, regarding what can be sold as such within the USA. If the vehicle is manufactured to exceed the limits in the regulation, it isn't covered by that regulation anymore and is now a motor vehicle, to be regulated by whatever laws (federal, state, and local) limit it's sale or use.
In the USA, Federal regulations don't explicitly define what any vehicle type is as far as what a state can or cant' call it, so each state has their own laws and regulations about vehicles and what they are allowed or not allowed to be or do. Local municipalities and such can also have their own regulations that could be even more restrictive, depending on what their state's laws allow (some states may specifically deny them the ability to be more restrictive).
The only place Federal regulations apply exclusively is on federal or federally controlled areas; even places built using federal funds aren't restricted if the state doesn't restrict it.
If the CPSC regulation was truly a country-wide law, there would be no (applicable) individual state definitions or regulations regarding electric bicycles, and no state could allow them to go faster, have more power, or be heavier, etc. However, since it is not a country-wide law, a number of states have higher speeds, power limits, etc, and few use weight anywhere within the definition. Here in Arizona, for instance, while we are limited to less than 20MPH, there is no power limit, nor any weight limit, nor any requirement to pedal. In New Mexico generally, an ebike is a moped, because there's no state classification for a bicycle with a motor being something separate--yet in Las Cruces, where Dogman lives, they have a local law (recently enacted) that does limit things and does create an electric bicycle category of vehicle.
It is quite a mishmash of different types of regulations depending on where you are in the USA. Technically, it makes an electric-bicycle tour of the USA difficult, because each state you pass thru, and evne each city, possibly county, could have different regulations, and in some places they may not be allowed at all.
EDIT: started a wiki article and linked to this thread as one discussion on USA ebike law
http://www.endless-sphere.com/w/index.php/Definitions_(legal)_of_an_Electric_Bicycle