A government proposal to give ultra-low emissions vehicles (ULEV) green number plates is little more than a spot of window dressing. Or bumper dressing, if you want to be pedantic.

Transport secretary Chris Grayling suggests the plates would serve as a “badge of honour” that could inspire take-up of ULEVs. That seems optimistic – I doubt the prospect of having a special number plate will make anyone more inclined to go and buy an electric car.

What will inspire take-up of ULEVs are things like lower costs, tax incentives and the continued development of charging infrastructure, all of which are a lot harder to resolve (and more expensive to sort) than designing a new number plate. 

But while the government might be better focused on those areas, the idea of green plates isn't without merit. 

The ability to differentiate ULEVs from combustion-engined cars could aid in the easy enforcement of low-emissions zones, EV-only parking bays and so on. Combustion-engined cars parked in EV charging bays are a fairly regular sight and, if you’re trying to charge your electric car, can be hugely frustrating. As with disabled blue badges, green number plates would make it much easier to spot cars that should be able to park in such bays, and might dissuade drivers of petrol and diesel cars from trying to park there.