http://news.bbc.co.uk/1/hi/technology/8114470.stm
The government are missing the point. They're trialling this in several cities, but neglecting rural areas.
Why's that important? Because they'll need to test just how useful this is in the countryside as well. I know more people live in the cities and are more likely to be near an electricity hook up point.... but that's the point. You're going to have plenty of people that think "I can't ditch the petrol motor, if I go out of town on holiday or for a day trip I might not get home again!"
Just trialling it in 8 cities proves nothing. They should have looked into trialling it in a rural area as well, maybe one near one of the test cities so they could if that affected people's driving habits.