I do understand that enforcement is only part of the picture, but it is a vital part. Taking a quick look at the 20's plenty site seems to give lots of stuff about campaigning for having a limit introduced. This is great of course, but perhaps as this is one of the first few city-wide limits to actually happen the advice on making it stick isn't so in-depth. That's partly why I posted the question in the first place.
I think non-enforcement of limits is a very bad move by the police; it undermines the authority of all speed limits, and it runs counter to the wishes of the population who identified speeding traffic as the single biggest cause of anti-social behaviour in the recent ONS paper. I'm regularly on-record as saying that I think all traffic laws should be enforced for all road-users. That said, where resources are constrained the ones that do the most harm should be targeted first. It's clear some cyclists have a reprehensible knack for scaring little old ladies, but some drivers have a knack for killing them. Whilst it's besides the moral point, it's also true as mickle mentioned that speed limits do not apply to non-motorised vehicles in law. Of course we, as cyclists, need to be part of a more careful, respectful, road use culture, but I see no hypocrisy for asking for a 20-limit in a built-up, demonstrably dangerous area to be properly enforced.
Thanks for the info about op crackdown Greg, I know it well! I've had some moderate success myself reporting really scary driving, it's a very sensible scheme. So, anyone had luck contacting PCCs, or attending the local police liaison groups, contacting their councils, or anything like that?