Bearminder,
That was a pretty weak excuse on the part of HR and smacks of discrimination.
I think a complaint to the ESC might be in order? It would be considered discrimnation to eliminate you based on your mode of transportation. It maybe that it wasn't such a good company to work for after all, if they made a decision based on just that. Unfortunately you brought the issue up during the interview stage, I am not so sure I would do that in the future.
Aaron
