With a G5 network it would presumably be possible to charge motorists by the km? Perhaps more in rush hours and in congestion spots. Environmentally the aim should be to reduce the total amount of traffic- Other alternatives could be higher parking fees in cities but that would hit the already beleaguered high street.
So a dilemma, less and cleaner traffic equals less income for the government. So road pricing where you pay for your use seems the only way? Automatic toll booths on motorways (they had them in Portugal in 1990 as I found out when my lift went through the barrier at 90kph and laughed that the toll was automatically deducted) would be simpler but might increase congestion on surrounding A Roads?
It will be interesting, the more remote areas of Britain are dependant on the car for basic services and, at times medical care. So should the cost per km in Cornwall be the same as in Essex? And then what about someone who drives down from London – do they pay at Cornwall rates, or London rates?