i am the drive up teller at the bank and the reason my bank doesn't allow people not in cars be it walking or bike or otherwise is from what i've been told insurance reasons. so far i've been working here since february and one guy on a mtb came up and he asked if he could do his transaction and i let him. i did see a roadie go to the drive up atm one other time.
of course i'm going to make it easier for my fellow cyclists and allow it.
on a sidenote my bank (HSBC) is having a "green campaign" and my manager asked us (the "team") to come up with ideas for the bank to go green. i said shut down the drive up, and she took it as a joke.