The regulation that sets out which offences do and don't carry Ontario demerit points is:
O. Reg 339/94 Click on it for a LENGTHY list of things that carry points. Basically you need to know that:
- Municipal by-laws for speeding can still carry demerit points
- Municipal by-laws for "disobey sign" do NOT carry demerit points
So yeah, basically anything that sounds like "fail to obey sign," or "disobey official sign" under a municipal by-law would be okay. As far as the type of sign, usually it's just a catch-all, just make sure they don't try to get you with one that talks about prohibiting turns.
The funny thing is that, even though the "municipal speeding" infraction can have demerit points, it doesn't go on your driver abstract. Insurance companies can access your HTA/Criminal Code driving conviction record, but I'm not sure that it includes the demerit point total. Again, though, 14 over does not carry demerit points with an HTA conviction so I'm fairly sure that 14 over with a municipal speeding infraction wouldn't have it, either. Regardless, talk to the Crown Prosecutors and see what they say. Some municipalities have speeding by-laws, others just rely on the HTA, but there should be a by-law infraction you can plead to. In the mean time, you might want to put together a disclosure request just to be prepared if the Crown is reluctant to bargain.