[army1959]

Originally Posted by karlafong

As far as the parking ... in large cities, especially, some stores contract with parking structures so if a customer buys something at the store, they are not charged for their time in the parking garage (we're still a quite car-centered society, if you couldn't tell). When you park in the structure, you are given a receipt or ticket, which you don't pay until you leave (the charge is usually based on how many hours you're parked). So if you buy something, the store "validates your parking." Why the word "validate" came to be used, I don't know.

As far as the bus, I think that's probably more of a film-making shortcut, although some cities do have certain zones where bus travel is free.

The term applies to parking garages. Often the garages are run by a merchant or group of merchants who own and operate the garage. While they will allow anyone to park there, they want random people to pay for parking unless they are patrons of the owner's business(es), who will get free parking. The term "Validate" means to signify or certify or verify that a customer is indeed a patron of the owner's business and is therefore entitled to free parking. "Validate" is the verb form of the adjective "valid" which means that the person is in fact a (valid) true customer of the owner's business and therefore does indeed get free parking.