Speed Bump vs Road Kill

Hey, listen up, slowpoke! This joke is funny 'cause it's playin' on words. So, like, a speed bump is supposed to slow cars down, right? But roadkill? Well, that's what happens when cars are goin' too fast, dummy! The joke is saying the difference between a speed bump and roadkill is about 40 mph, meaning if you're goin' faster than that, you ain't gonna slow down for nothin'!