>>>Personally, a society with two sets of laws (or who knows, if Sharia caught on, how many others would want their own set of laws) is not a society in which I'd want to live.
>>
>>Not defending sharia, but you live in a society with 3 sets of laws. Federal, provinical and municiple.
>
>But they don't conflict.

That's untrue, there are often cases of different levels of government taking each other to court over matters of jurisdiction.

> We don't have federal traffic laws, for example (that I'm aware of).

Sure we do. Impared driving.

"In Canada, two levels of government deal with impaired driving. The federal Criminal Code is applied at BACs of .08 and over. In addition, nine of Canada’s 13 provincial and territorial jurisdictions impose administrative licence suspensions on drivers whose BAC is under .08. Those drivers immediately lose their licence for four to 24 hours, longer with subsequent violations."
http://www.safety-council.org/info/traffic/impaired/BAC-update-06.html