community speed cameras: crowdsourcing safety data

The speed cameras on the Pershore Road just don't work - I'm regularly nearly run over while trying to cross by people doing about 50, encouraged by the dual-carriageway look of the road, and it makes me nervous that someone's going to get horribly squished soon.
Given that more speed cameras just leads to stop/start traffic, and that presumably the Council doesn't do anything about speeding without evidence, perhaps the Council could lend out a portable speed camera to interested groups. Volunteers could then track the speeds of cars, displaying the data back to the motorists and storing the data to be used as evidence in road planning. The data would just be speed, rather than storing any identifiable info on the car (i.e. licence plate / photos).

You might also want to read the Birmingham B29 article about this idea.