I was returning from Oxford yesterday afternoon on the A4074, when I came upon a queue of traffic of about a dozen vehicles doing 30mph. What was causing this moving holdup: a tractor or a milk float? No it was a G-Wiz. The owners were probably smugly thinking that they were causing no emissions. How wrong they were. Think of all the vehicles behind them forced to drive at less than the optimum economic speed for their vehicles? Plus (given the area) the electricity for their G-Wiz almost certainly came from the local coal fired power station at Didcot. Surely there should be some kind legislation to restrict them to its sensible environment of the City? Major routes and A roads are not the safe place for such slow moving vehicles.