So how come they didn't use the word evacuation? It it truly interchangeable w/ vacation?

I think that the vacation mentioned by TEd does not pertain to an emptying, but to the cessation of an official designation of the drive as a public road. Typically, public roads are dedicated when created by the donation or sale of land for the purpose of establishing a public road, and roads are vacated when they are removed from that dedicated purpose. In this context, "evacuated" and "vacated" are not synonymous.