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Comment by hattar | Hacker News Reader

Why not place an arch before the bridge that will impact but not damage vehicles going through? This exists in the entrance to most parking garages.

Edit: like this https://www.jpsiteexperts.com/wp-content/uploads/2014/04/cle...

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Placing an obstacle between the bridge and the intersection would be fairly pointless, because once you hit it, it would be too late to stop before hitting the bridge.

(EDIT: in addition, a hanging warning sign would have to be suspended from something. My guess is any such structure would need to be made very sturdy and expensive, or else it would just get knocked down and increase the hazard to pedestrians and property when somebody hits the sign at significant speed.)

Placing the obstacle anywhere else would impede vehicles that aren't trying to go under the bridge.

Look at the video. Such a structure already exists. There is a yellow beam meant to protect the bridge right in front of it. It probably does most of the can openjng to spare the bridge

The parent commenter asked for something that would "impact but not damage" vehicles, and the protective beam undoubtedly fails at that purpose.

There's an intersection right before the bridge - the beam is already at the "warning" location to protect the bridge. Bridge strikes arent' cheap and train companies HATE closing bridges for any reason (including replacing them).

Or maybe red warning lights instead of yellow warning lights. Maybe they have changed it. But yellow lights to me doesn't suggest "you absolutely need to stop".

edit: okay. Now they have a sign. With white lettering. In a location where we know from years of experience drivers aren't looking. This makes no sense to me. Everything about this is bad design.

There are lights that come on and the stoplight changes to red when an overheight vehicle approaches.

White is usually used to indicate information. And in the video in the link the signal turned red after the cab of the truck passed the signal.

I mean I get it. It's funny. But if it were designed well, there wouldn't have been 100+ accidents.

There are at least five signs at eye level on the road leading up to the bridge, four of which are the standard yellow warning signs: https://imgur.com/a/owITLZC

In addition, the illuminated "OVERHEIGHT MUST TURN" sign flashes to attract attention.

I get what you're trying to say, but this bridge is better-marked than the vast majority of road hazards one might encounter. There's a certain point beyond which it doesn't make sense to keep spending time and money protecting people from themselves.

"OVERHEIGHT MUST TURN" is such a stupid phrase. It doesn't even mean what they intend: ”OVERHEIGHT! MUST TURN!"

Every time I drive through that intersection I’m amazed when I remember how fast most of the trucks are going by the time they get to the bridge.

And how's that working out for them? 100+ accidents?

The bridge just shrugs the hits off it is very tough. So the damage and the problems are really for the trucks not observant enough to see half a dozen warning signs and lights.

They are the ones who end up paying, not the railroad that owns the bridge.

There's a slightly lower heavy steel bar in front of the bridge to prevent people from hitting the bridge itself.

There is an arch... or a metal thing you hit instead of the bridge.

It should be WAY out, almost at the intersection.

That would, I'm guessing, make things worse by both increasing the risk of t-bone collisions, and giving drivers turning from the cross street even less chance to do anything avert a collision.

It's possible that, short of removing and replacing the bridge (which would have its own consequences, since it serves an active rail line in a major city), the only thing that would actually help much is getting stricter about what size of vehicle people are allowed to operate without special training and a special class of license.

I know what would probably work. A large, dark, covering roof, which slants lower and lower until it’s the height of the bridge.

It looks like one exists, but it’s right before the bridge and not enough warning to stop a car traveling quickly.

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