I'd say it is the cost of fuel vs the cost of public transport. I've taken the train London-Paris for £58 return, or flown to Spain or Greece for less than £50

I'd say it is the cost of fuel vs the cost of public transport. I've taken the train London-Paris for £58 return, or flown to Spain or Greece for less than £50 return with easyjet or similar. Even with 2 or three of us travelling it would cost far more than that to do it by car (plus have to sort out European insurance and breakdown cover), and then struggle to find places to park in Paris, and pay through the nose for it. Instead I can get on a train to Paris for just over 2 hours, or I loved leaving work one day at 5pm, getting the plane to Amsterdam for £27 each way, and arriving there at 8pm UK time (9pm Dutch time), and was in the city centre drinking by 10.15. If I'd tried to do that by car...