Would you say that the high fuel prices are changing your driving habits? Are you more likely to walk/cycle or use public transport now? How expensive would fuel have to be to stop you driving a car?
You forgot to mention the carrying of all the bags and cases, waiting in the cold because they aren't running on time, missed connections, the taxi or walk the other end. Family of 4 travelling from Hampshire to Glasgow in a 2.5 v6 Vectra estate on LPG cost me £75 return door to door. £18.75 per person. Public transport cant match that cost or comfort.
Are you more likely to walk?
The LPG case is a compelling one but is the gentle fuel duty going to last much longer? Also, what's the performance like on LPG? I'm inclined to think that it's woolier than running on petrol. I still favour diesel as a road car fuel.
I'd stop driving it was leaving me with no money. If fuel rises in price though, will the bus cost more?