rats on the track

Said to someone who is giving you a ride or going on a trip and is taking way too long to get ready/leave a parking space/pass by a green light. From Seinfeld where Elaine was waiting for her train to get going when it stopped. Implies that there should be no excuse why you aren't moving.

Why won't this train move! They probably stopped because there's rats on the track!

Go! You could of turned left six times by now! Are there rats on the track or something!