As numerous stand-up comedians have observed over the years, one of the least explainable developments in banking history is the addition of Braille on drive-up ATMs. Assuming the driver of the car would be the same person conducting the banking transaction, one does have to wonder why banks would even bother putting braille lettering on such a machine in the first place. If a sighted driver is acting as an intermediary for a blind passenger, Braille would still not be necessary.
There are actually a few reasons why banks put Braille on drive-up ATMs. One reason is concerns over customer privacy. If an automatic teller machine were programmed to "talk" to visually impaired customers electronically, bystanders with evil intent might overhear private information such as personal identification numbers, account balances and account numbers. The actual number of times a visually impaired customer might actually walk up to a drive up ATM to conduct business may be low, but banks cannot be too careful when it comes to protecting private information.
Another reason banks put Braille on drive-up ATMs is to satisfy federal regulations regarding accommodations for the handicapped. Under these laws, public institutions are required to make most if not all of their services accessible by the visually, hearing and physically impaired.
In the case of drive up ATMs, the Braille lettering may be considered all but superfluous, but it does satisfy the letter of the Americans with Disabilities Act. Blind customers would have the ability to read the numbers on the machines, although few ATMs actually provide much assistance beyond that. The information on the ATM monitor, for example, cannot be read by a blind customer without outside assistance.
There is every possibility a new generation of automatic banking machines will incorporate truly useful accommodations for the visually impaired, but for now the best any bank can do is provide Braille lettering on all their ATMs, whether or not a visually impaired customer chooses to use them. Accommodations made to satisfy federal regulations are not necessarily required to be practical, just available. Banks which fail to provide such modifications for customers with disabilities may find themselves vulnerable to lawsuits and fines, so the safest solution is to provide Braille on drive-up ATMs.