11'8" is a 28 inches shorter than the current minimum permitted (for new structures) by federal law. So, it a surprisingly low clearance.
That, and it's really pretty common for people to not pay much attention to road signs. For example, in my neighborhood, there are quite a few intersections with "no turn on red" signs posted. And it's a regular occurrence for people behind me to lay on the horn in a rather distressed manner when I'm first in line, and choosing to obey traffic laws. I live on a street with no outlet, and my kids just love watch lawn care companies that have gotten themselves stranded from the living room windows. It would appear to be a tad bit difficult to back your way straight down a full city block when there's a 15 foot trailer hitched to your extended cab pickup truck.
For what it's worth, I used to work about a block away from a completely different underpass that was also old and had a very low clearance. And I suspect that the only real reason why that one isn't similarly famous is that none of us ever thought to set up a webcam.
That, and it's really pretty common for people to not pay much attention to road signs. For example, in my neighborhood, there are quite a few intersections with "no turn on red" signs posted. And it's a regular occurrence for people behind me to lay on the horn in a rather distressed manner when I'm first in line, and choosing to obey traffic laws. I live on a street with no outlet, and my kids just love watch lawn care companies that have gotten themselves stranded from the living room windows. It would appear to be a tad bit difficult to back your way straight down a full city block when there's a 15 foot trailer hitched to your extended cab pickup truck.
For what it's worth, I used to work about a block away from a completely different underpass that was also old and had a very low clearance. And I suspect that the only real reason why that one isn't similarly famous is that none of us ever thought to set up a webcam.