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Comment by chrisseaton | Hacker News Reader

What is so special about this bridge? Why do people drive under it without checking their height? You wouldn't normally think you can just drive under any bridge, would you?

It doesn't even look like a very low bridge. Why do people approach it without a care in the world at full speed?

My vehicle is only 2m tall and I still do take a quick look at height signs as I approach them.

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According to the Wikipedia article [0], the bridge is very old and does not meet current clearance standards:

> It was designed in the 1920s, and opened in 1940, with a clearance for vehicles of 11 feet 8 inches (3.56 m). This was a standard height at the time it opened. The standard clearance, since 1973, has a minimum height of 14 feet (4.3 m), which is 2 feet 4 inches (0.71 m) higher than the bridge as built.

I imagine most trucks are built to be just under 14 feet so that fitting under bridges is not usually an issue.

Another thing I’ve noticed watching some of these videos is that most of the accidents are rental trucks. Presumably many of these drivers have never driven a truck in their lives and ignore clearance warnings out of habit.

[0]: https://en.wikipedia.org/wiki/Norfolk_Southern–Gregson_Stree...

I ruined the top of a rental truck. It wasn't bridge it was a tree overhanging the street. Partly because the tree was not directly overhead like a bridge I didn't notice it was too low and all I was trying to do is park the truck so I was going slow but yea, smashed the top of the truck. Truck Rental company says it happens at least one a month.

https://photos.app.goo.gl/Q6QS9Uy3HNijYXEt7

A substantial number of these crashes (maybe the majority?) are rental trucks, being driven by people who aren't accustomed to operating a large vehicle.

A typical driver of a car, minivan or SUV in the United States will virtually never encounter a bridge or other obstacle whose height above the road is low enough to matter to them, so most people simply never have a reason to pay attention to those height signs.

The one exception is parking garages, which often have very low roofs, where most trucks or full-size vans won't fit. But that's a totally different situation.

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.

I speculate that the most special thing is that the guy has a camera on the bridge. We see everyone who hits this bridge. That combined with a pretty low bridge (it was raised a few years back but it is still low enough to catch a lot of vehicles) and a culture of using phones to give us driving directions gives us this situation.

You're a new driver, following Google Maps, and the fact that you hadn't cared about the height of your vehicle WRT your route just got expensive.

But that could happen anywhere in the country.

What's so special about this bridge that means it gets so much coverage. It doesn't even seem extremely low.

There are two cameras pointed at the bridge 24/7 and a guy posts every collision.

It is low enough to exclude a large percentage of vehicles and it isn't exactly signed very well. It's just bad design.

It’s was within spec when it was built.

It's much lower than most bridges in the US so truckers not used to thinking about their height because they're below the height of most bridges can get caught. Add to that many of these crashes are in rental trucks so you have people even less used to having to think about the height of their vehicle encountering this abnormally low bridge.

Because in general, people are human.

Part of it is the American ethos of "the rules don't apply to me". That often works. But not with bridges.

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