Spanning the main road through the Washington Park Arboretum is a pedestrian bridge, formally known as the Arboretum Sewer Trestle (you don't need me to explain why). The bridge is marked Clearance: 9'0". There are warnings posted far in advance. There is even a laser sensor above the road which triggers flashing yellow warning lights if an over-height vehicle approaches.
Despite all these precautions and warnings, people still crash into the bridge with alarming frequency, at least according to one of my colleagues who drives under that bridge every day. (If you ask the Department of Transportation—as my colleague did—how often vehicles strike the bridge, you'll get a number far, far below the actual number. Probably because most of the incidents go unreported.) The evidence by the side of the road suggests that the accidents are usually caused by somebody who forgot that he's pulling a U-Haul behind him.
Or maybe it was a bus carrying a high school softball team.
The driver of the bus was blindly following the instructions of his GPS navigation system and never saw the flashing lights or the clearance sign. He figured the route must have been good, because he set the GPS to bus mode. You can read the article to find out why that didn't work.
Remember folks, it's great that you have a computer to give you directions, but it's still your responsibility to drive the vehicle.
Bonus chatter: My bridge-obsessed colleague also introduced me to the Om Nom Nom Nom meme by forwarding a picture of the crash site with a pair of googly eyes drawn on the bridge overpass. Here's an interview with the source of the phrase om nom nom nom.
Oh, and my bridge-obsessed colleague also wishes somebody would install a web-cam pointed at the bridge: When the laser detects an imminent collision, it starts recording!