(Strip Number 6061, Original Publication Date, 31 March 1982)
Panel 1: It's the end of another busy day at John's
Panel 2: We next see him in rather congested traffic; since he's sort of fond of stating the obvious, he tells a woman who is neither blind nor oblivious to look at the bumper to bumper traffic.
Panel 3: He then points out that they haven't gone any faster than fifteen miles per hour (a few years later and he would have said 25 kn/h) since they started.
Panel 4: He then asks who was the idiot who first called this time of day rush hour.
Summary: The 'joke', of course, is that John doesn't understand that everyone is in such a rush to get home, the streets are clogged with vehicles. Then again, we're dealing with a clod who hangs out with a man he dislikes so he can feel better about himself so we can't expect brilliance.