Drivers do not pay attention and/or are illiterate. We have our own version of this northwest of Chicago, it is a low single-lane covered bridge in a quaint village but is not far-off the beaten path. A few years back it had a bad brush with a truck so to protect the bridge covering they gave it a steel sub-structure. It has warning lights and signs but still racks up a couple dozen kills per year. Unfortunately, it has no public camera on it that I'm aware of. It was hit last week and again this week and it makes the news every, god, damned, time.

https://longgrovehistory.org/bridge-damaged/

https://www.dailyherald.com/news/20221003/iconic-long-grove-bridge-struck-for-42nd-time-since-2020

Have you not seen this before? The videos are weirdly cathartic to watch, i go back every few months and just binge them. I could have sworn I first saw it here on SE, but it may have been on Jalopnik?

At any rate, they can't raise the bridge because it's a railbridge, they can't lower the roadway due to 100+ year old infrastructure underneath (pipes, etc). The 11'8" is no longer accurate though, I believe they managed to eke out an additional 4" or 6" somehow in the last couple of years.

Signs and warnings start popping up blocks away if you're overheight and it is ridiculously simple to go around. Like, go left a couple blocks and then go right to cross the train tracks, and then right again to get back to the original road.

It pops up on my radar every few years. This vid in particular was just a perfect bit off the top. Had to share. It's 12'4" now, hence the 11foot8+8. They were able to add 8 more inches by leveling the railroad tracks or something.

Well, what they do with some bridges with low clearance here in Europe, is that they install chains hanging down to the height of the clearance in front of the offending structure.
This way the driver hits the chains and is alerted well before he actually peels off the top of the truck.

They do that here, too, though obviously not with every overpass.