Out of Oxford or into Oxford? The question of which bus passengers the Thornhill park-and-ride is used by and intended for has exercised correspondents Graham Jones and Don Manley over the past two weeks in the letters column of The Oxford Times. Mr Jones argued that incomers should be preferred and would be put off by Oxfordshire County Council’s proposed £2 charge for short-term (up to 11 hours) parking. Mr Manley pleaded the cause of those of us wanting to leave Oxford for London and opting “to sit in a coach at maybe a quarter of the price of standing in an overcrowded train”.

I shall address the coach-versus-train question presently. Meanwhile, let me ask another question: What of the people making use of Thornhill who are neither exiting nor entering Oxford but instead taking advantage of a bloody cheap way of gaining access to the capital from other parts of the country? Just as Kidlington Airport has become London Oxford Airport (Kidlington), Thornhill might appropriately be restyled, say, London West Car Park (Oxford).

I wonder if anybody has ever made a careful study of precisely who is making use of this costly (to Oxfordshire council tax payers) facility.

That Thornhill was popular with outsiders was brought home to me in a conversation I enjoyed some years ago while waiting there to board the Oxford Tube. My interlocutors were a charming middle-aged couple, he a GP — it’s amazing what can be learned in a five-minute chat — living in Edinburgh. They had been staying with a family member in Cheltenham, and were now off to visit friends in Earls Court.

The pals had advised that taking the coach from Oxford’s park-and-ride was by far the most convenient way of reaching them. They made this clear, it seemed, to any visitor who was passing close to Oxford, along the M40, say. Parking at Thornhill also dispensed with the tiresome business of what to do with the car, saving a fortune on what they’d be paying to have a vehicle in London.

At the time of our conversation, there was no charge at all for parking at Thornhill. Today’s charges are £6 for up to 48 hours and £9 for up to 72 hours.

The county proposes increases to £8 and £12. These are hardly off-putting rates when measured against what is levied for a few hours’ parking in London, never mind the congestion charge.

Speaking of congestion, there were serious delays in Park Lane on the day I journeyed to London with the Scottish couple. As a consequence we were diverted through Earls Court. The Scots were delighted to be able to step off the coach directly opposite their friends’ flat.

At the time of this journey, I was a regular user of the Oxford Tube. I usually drove round the ring road to Thornhill to avoid the tedium of all the stops you endure if you board at Gloucester Green. Trouble was, there was sometimes a long hunt for a parking space. (This ought to be cured by the 500 new ones. But for how long?).

My disenchantment with the service grew after two occasions when a trip to Opera Holland Park was spoiled by difficulties getting home, with all the buses full by the time they reached Shepherd’s Bush. The second time, when there was a Kings of Leon concert in Hyde Park, we had to a summon a cab to take us to Thornhill.

As I think I may have mentioned here before, the Oxford Tube’s vehicles are not comfortable; their legroom, except in a few favoured spaces, is horribly constricting.

What swung me firmly in favour of trains, though, is that they offer a faster journey at a significantly lower cost — off-peak, at least (which is when I usually travel).

On dozens of trips to London in recent months, I have rarely paid more than £14.50 for my return tickets as a consequence of making an online booking, involving nominated services, with First Great Western.

The whole thing is done in two or three minutes on the computer. FGW even goes to the trouble of posting the tickets to me, at no charge.

The outgoing journey is generally aboard a High Speed Train — the 3.31pm, since you ask — on which I always have a reserved seat, usually at a table in the quiet carriage.

How much more civilised this is than being crammed aboard a stuffy coach crawling through Oxford’s suburbs surrounded by young people yakking interminably into their mobiles.