sure its cheaper to drive?
i worked out that personally the price of a monthly season ticket was cheaper than fuel (45-50mpg derv), servicing, general wear and tear. thats for a 36 miles each way journey.
I'm the same though it's a much smaller commute I have now at circa 40 miles round trip - monthly train/bus ticket doesn't even cost the same as my fuel never mind other running costs. But then again this will vary massively by location.
Plus it's an absolute pain in the arse. I'll get the train for a few weeks during the summer when I don't mind a 20 min drive turning into an hours commute, trying desperately to line up trains that will connect with the follow on bus at around the same time...when it's light and reasonably warm - in winter it's just not on