The subject has been bouncing around for a number of years. Consultation has supposedly been taking place in true government style.
I cannot get my link to stick here, but try going to the DfT website at
www.dft.gov.uk and typing Public safety zone: a consultation document into their search engine.
Err! just edited to say my search suggestion didn't work. Sorry type PSZ in their search engine and have a browse around...
Oops! edited for a second time try this
http://www.dft.gov.uk/stellent/group...on_503312.hcsp
regards