An annual ticket -- something that you have to commit to for a complete year, don't forget, despite not really knowing that you will definitely be needing it -- costs about £3000 per year. On top of that, I need to pay £600 per year for parking. So about £3,600 per year in total.Is it though? How much is your season ticket?
My car costs me about 10p per mile in petrol. Yes, I have to pay for lots of other motoring costs. *But I would be paying these anyway*. That's the problem with the train -- you are comparing the marginal cost of the car with the absolute cost of the train. But nonetheless, that's the comparison that is open to you.
I work 4 days a week in London, incidentally, with 20 days holiday per year + 5 or 6 bank holidays (I forget exactly how it works). It means about 183 working days per year. Which means that £3000 train cost works out as about £20 per working day. That's a LOT more expensive than the marginal cost of driving, even including the £1000 per year parking at my work.
I didn't actually mean the cost of commuting, though. I would never drive into the centre of London anyway. I meant incidental train journeys, particularly where there are two of you. I would never dream of taking the train to Guildford, for example. It would involve:
* A 2 mile walk to the nearest train station, which is unmanned and has no ticket machine.
* A wait for the train that comes as little as once every 2 hours.
* A cost of between £5 and £10 each, from memory.
* Having to get from the station to the destination (not too bad, as the station isn't too far out of town).
The whole journey would certainly cost in excess of £10 and would take an uncertain length of time, but certainly at least an hour. Compare that to an 8 mile drive that takes about 20 minutes. The train isn't even an option worthy of consideration.