This happens when you witness a line of traffic in which a bunch of dumb ass drivers are tailgating each other only to back off and repeat the process again. Characterized by people who brake constantly while driving and continuous speeding up and slowing down. It can be especially frustrating if this happens on the highway in the left lane when you are in a hurry and you don't want to get caught up or when it occurs on a single lane road where you are unable to pass. Resembles that of an accordion.
Looks like Steve is gonna be late to work again on the account of The Accordion Effect.