Comment by alexgieg

Your first example fits what I said. Notice it specifies what Canadian provinces should do. That's a clear geographic restriction, isn't it? But yes, the moment Canada were to become able to enforce it upon some other territory, it'd do so. The only limitation is that it cannot, not that it wouldn't. We'd then say those territories came under Canadian jurisdiction.

The same goes, I suppose, for the UK code you refer to. I imagine the British legislators specified clearly what roads are under its control. If not, then yes, that's the expectation, exactly like is happening right now with their censorship laws.

To learn more on this Google for the quite famous phrase "Parliament can criminalize smoking on the streets of Paris”. You're going to either double facepalm, or be horrified, if not both.