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Comment by ragebol | Hacker News Reader

So, what do you propose? Knocking them down? Put fences? Which are you going to do that on? Are you going to fend off all the people using those bridges for destroying their commute? None of those options are cheap either. Even selecting the bridges to keep/not keep takes time and effort and thus money.

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In the town where I’m from in Germany, exactly this happened: a major bridge was unsafe - one of two major roads leading to the crossing of the river rhine. It was closed and torn down, replacement will take a few years. In Berlin, one major river crossing was closed because it was unsafe, then torn down and replaced. Another was severely impacted and partially closed, it’s now replaced with a temporary bridge. Full replacement is expected in a decade or so. People adapt. Life goes on. It’s better than having the bridge collapse with people on it.

Anything is better than people on a collapsing bridge, obviously. But you can only fence it off when you know its too bad. Checking that can be very expensive. So if you just don't know which of 450 bridges are bad, what do you do? Fence them all of and spark at least outrage? Safest option. Finding out what to do is already expensive

You can start off with warning signs. I doubt bridges would collapse if pedestrians or bicyclists use them but sings could fend traffic off.

Second, the size of the vehicle is important. Larger vehicles like trucks get these poor bridges lifespan shortened drastically. Trucks and busses could be rerouted on safe bridges and so on.

I generally am not afraid of bridges because they have convinced me that they're safe but if a bridge were to collapse under me and I'd make it out alive I'd probably have a bridge phobia.

Here's a tweet with a picture from December of 2018 of the bridge that collapsed today, showing a large steel beam rusted completely through.

So you could start with the lowest hanging fruit, the bridges that are in such bad condition that people post pictures of them on Twitter.

Here's the tweet you were referring to, I think: https://twitter.com/gpk320/status/1078885655634157569

How did people in that town pay for tearing down and replacing the bridge?

The problem Pittsburgh encounters is even demolition costs money. Can't squeeze blood from a stone.

This very thing occurred in PGH with the Greenfield Bridge[0]. This caused significant disruption because the bridge spans a major highway to the eastern suburbs. Of course, the infrastructure issues with that bridge were rather obvious, since chunks of concrete would fall on to the highway (necessitating netting to be installed).

[0] http://greenfieldbridge.otmapgh.org/

The solutions are easier in a growing city than a declining one.

I know of a relatively small bridge in rural Ohio that simply has barriers placed in front of it. It's still walkable.

They did the same with an old wooden bridge near where I grew up. In the early 80s, you could still drive across it. Later they closed it and barricaded it. Eventually in the 2000s, they preserved it and built a park around it.

Of course, this bridge only carried about 10 cars a day, mostly as a novelty, prior to closing. It's an entirely different animal to close a bridge in a major city.

> It's an entirely different animal to close a bridge in a major city.

Minneapolis/St. Paul managed to adapt when the busiest bridge in the state collapsed.

I know of a couple of medium-sized bridges in upstate NY that have completely collapsed and the state has just abandoned them, with some barriers thrown in front and that's it. Funnily enough they still show up as routes on Google Maps, but OSM has them removed. I decided to leave it as is to fight the Google mapping monopoly power.

They could install micro-tolls ie ezpass and charge everyone a use fee.

Make some free. Let the communities who need them pay for them.

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