The M25 needs urgent widening before it grinds to a complete halt; I am on it every day and to travel - say - from Gatwick to Heathrow (less than 40 mls) is a total lottery.
Planes don't wait because of a crash/delays at J8 and there is no direct transport between the airports, except via the M25.
Finance is needed by whatever means - to be repaid (as in Europe and the USA) by the impending tolls. Thus, those who don't use it won't pay.