Express Question

Here's a random question to pick your mind/the BOD's.

What is the history of tag teams named “Express” in wrestling? Never really made any sense to me.

The only one that really makes sense is the WWF's Orient Express since that was, you know, an actual train. But obviously that name was a takeoff of the way more famous ones before it like the Rock N Roll Express, Midnight Express, etc.

But how did it start? Why? It is just “cause wrestling?” Or maybe something about it was more culturally significant in the 70's or something and I just don't get it?
Midnight Express was a famous movie about a student getting thrown into Turkish prison, which came out in 1978 and provided the basis for the tag team's name.  And then basically everyone else that followed was playing off that.  Which reminds me of a Dusty interview from many years ago, when WCW was putting together Steve Keirn & Bobby Eaton as a tag team.  Apparently he was pitched “The Fabulous Express” as a name for them, but shot it down because it sounded like a fast food restaurant.