Motorists pay approximately £40 billion in tax every year.
Roads (as a whole) cost around £9 billion every year
Subsidies to (English) buses cost the state £2.3 billion last year. (Source:
DfT)
Estimated cost of Traffic accidents in GB is around £15.5 billion. This includes hospital costs, police costs, and various other costs. (Source:
DfT)
So if those figures are correct, that makes £24.5bn of benefits going to motorists, and they are paying £15.5bn more than that.
However, that doesn't account for the many other costs associated with motoring, some of which
edmin_m mentioned, for example...
- CO2 emissions causing climate change
- Other pollutants (eg. particulates), causing health problems (medical treatment, loss of quality of life, etc.)
- Loss of quality of life to all those affected by noise pollution or congestion
Those are much harder to quantify financially. However, the £15.5bn 'surplus' paid by motorists from your figures, divided by 60million population comes to about £250 per person [per year]. By contrast, I'd imagine any reasonable estimate of these more subjective costs from motoring would come out in the thousands of pounds per person, it seems completely implausible to me that it would be as low as £250.
That would therefore suggest that, despite all the complaints from motorists about high taxation levels, motorists are in fact getting a net subsidy when all costs are taken into account.
(EDIT: I'm also unclear what is included in your figure of £9bn for the cost of roads. Does that refer to the cost of building and maintaining roads only, or does it also include the cost of policing, administrative costs from licensing vehicles, administrative costs of running MOT tests, etc.? If it doesn't include the latter then that would imply motorists are receiving an even bigger subsidy).
(EDIT2: On the other hand, in motorists' favour: How much, if any, of the costs of traffic accidents that you quoted is recoverable from insurance companies?)