I went to a presentation by Sustrans this week entitled "Should cars be priced out of london" - deliberately provocative, really turned out to be a promo event for the Wolfson economic prize winning scheme to introduce a form a road pricing (I think development is now being funded by the government). The guy, Gergely Raccuja, who developed it presented it and it's basically the Aviva insurance app on steroids. The get rid of road tax, congestion charge and low emission charge and its all done through a tracker in your car with road usage charges processed through your insurance. This means that diesels are unlikely to be banned, but may have higher "road pricing" depending on where you're driving it. What's really driving the whole initiative is that cars are so much more efficient that even though we have 40% odd more cars on the road since 2000 revenue from fuel duty and car tax has gone down... Could work and hopefully means that people who bought diesels won't have to worry for too much, the only worrying thing for us Scooby drivers is whether the insurance companies profile our driving on G-force !!