you all made me curious so i had to find out why there was braille on the drive through atm...and here is what i found......
Drive-up ATM buttons are marked with braille because federal regulations require it. To be specific, section 4.34.4 of the ADA Accessibility Guidelines for Buildings and Facilities (Appendix to Part 1191, 36 CFR Chapter XI, issued pursuant to the Americans with Disabilities Act of 1990) says, "Instructions and all information for use [of an automated teller machine] shall be made accessible to and independently usable by persons with vision impairments." Drive-up ATMs, unlike the walk-up variety, don't need to be wheelchair accessible, but the rules make no exception regarding accessibility by the blind.
The Edge... there is no honest way to explain it because the only people who really know where it is are the ones who have gone over. - Hunter S. Thompson (July 18, 1937 - February 20, 2005)