This skewing of cost becomes more important when public transport is brought into the equation. In most cases, the choice a person makes is not between driving somewhere and staying at home, but between using private transport and using public transport. If a person has already paid a large amount for his car he will use it. The way we arrange motoring costs means that public transport never gets a look-in. This is because for any given trip, the traveller has already paid a very large part of the cost of going by car in the up-front costs of buying, registering and insuring the vehicle. If he goes by public transport, the fixed cost of his private transport stays the same – he has already paid for it, except for the petrol, which is only a small cost – but he must pay for public transport. He has an incentive to travel privately rather than by public transport. This is not in the interest of the State.