At either end of the Golden Gate Bridge, there are ribbed joints in the surface of the roadway. I don’t think they’re expansion joints, I think they simply connect the surface of the approach to the surface of the bridge itself. Since they’re about two feet wide, the ribs add traction to the metal surface in wet weather. They also make a really neat sound, especially in rush hour traffic. Like mechanical (or maniacal?) barking sea lions.

This post originally appeared on White Noise Lounge.