Since 2001, Canada's Motor Vehicle Safety Regulations (MVSR) have defined Power Assisted bicycles (PABs). They are currently defined as a two or three wheeled bicycle with an attached electric motor of 500W or less and which is capable of being propelled manually. Furthermore to meet the safety requirements set down by this legislation it must meet the following; when engaged by muscular power it must cease assistance when muscular power ceases or if powered by an accelerator controller cease power when braking and be incapable of providing assistance above 32 km/h and bear a label that is permanently affixed by the manufacturer and appears in a conspicuous location stating the vehicle is a power-assisted bicycle.[5][6]
There is however still confusion over the various legislations involving Electric Bicycles. This stems from the fact that while places like the US and Canada offer some Federal regulation, the legality of road use is left to the various States or Provinces and then complicated further by municipal laws and restrictions. Further more there are a range of classifications and terms describing them, "Power-assisted bicycle" (Canada) or "Power assisted cycle" (United Kingdom) or ”Electric pedal assisted cycles” (European Union) or simply "electric bicycles", and as such in some cases have varying laws according to their respective classifications in some places.
I discovered these downsides when, on my third day with the bike, I got a flat tire and had to carry it onto the subway with me for those last few miles back to my apartment. The cause of the flat is unknown; the bike mechanic who eventually fixed it didn’t see anything wrong with the rims. But the experience of trying to maneuver an almost 40 pound e-bike on and off a crowded subway car during rush-hour is not one I can recommend.

The federal Consumer Product Safety Act defines a "low speed electric bicycle" as a two or three wheeled vehicle with fully operable pedals, a top speed when powered solely by the motor under 20 mph (32 km/h) and an electric motor that produces less than 750 W (1.01 hp). The Act authorizes the Consumer Product Safety Commission to protect people who ride low-speed electric vehicles by issuing necessary safety regulations.[63] The rules for e-bikes on public roads, sidewalks, and pathways are under state jurisdiction, and vary.