ANPR cameras have been used in the UK for decades to mainly enforce things like tax, inner-city emissions restrictions and speed. I realise this has recently become a contentious issue via Flock in the US, but it seems to me a fairly efficient way to enforce these things. There are two big differences with the American model - data is kept within the police (not a private third-party), and policing is not nearly as well resourced.

If you are concerned about privacy, then a mode of transport that doesn't require you to have a unique identifier plastered over your vehicle seems like the better option to me.