This Sign Stopped a Car Dead

This sign's steel legs just stopped a car dead. The big signs along highways are built to swing out of the way. Make the legs weak enough to snap, and the car gets through. But the whole sign comes crashing down onto the roof. So each leg sits on a plate that slides off its base. Just under the sign, a hinge lets go. When a bumper knocks a leg out, it swings up like a gate, and the car drives right under. This 3D animation shows how breakaway supports on big roadside guide signs work. Each steel leg stands on a slip base: two plates clamped by bolts that sit in open slots. A bumper knocks the upper plate off the lower one, a fuse plate just below the sign breaks, and the leg swings up on its hinge so the car passes beneath the sign while the other leg holds it up. The rigid sign and the thin-leg sign are thought experiments, the hinge is drawn as a simple pin hinge, and the crashes are illustrations, not engineering tests. #Shorts #HowItWorks #Engineering