There's nothing about using transit that would decrease the number of bridges in a city like Pittsburgh. The transit needs bridges to cross rivers and hollows too.
An awful lot of these bridges started as footpaths and ox-cart turnpikes.
The question is twofold: how many bridges do you need with much better efficiency? A two lane bridge with buses costs less than the 10 lane car bridge you need to carry the same number of people.
If you go on a road diet your maintenance costs go down because you’re building fewer lanes, not having tons of bypasses and bridges which exist only to take pressure off of congestion at chokepoints, etc. Those reductions mean you can spend correspondingly more on the necessary core infrastructure.
Broadly-speaking yes, but none of that would have addressed this collapse. This was a two-lane bridge between two major neighborhoods. People need to get to those neighborhoods and they'd have to divert about a mile north to do it without this bridge.
Pittsburgh is built at the intersection of three rivers and atop the folded spine of the Alleghenies. Any way you slice it that city's gonna have either a lot of bridges or a lot of grumpy people who can't get anywhere.
Yes, the point was just that if you use infrastructure more efficiently your maintenance dollar won't have to be stretched as much. They'll still have plenty of bridges but if they focused maintenance on the things used by residents rather than people driving in from the suburbs that'd free up a lot of funding.
The people driving in from the suburbs are who work in the city. Taxes and a huge percentage of the land being owned by non-profits keeps residents to a minimum (not to mention most of what can be used for housing in city limits is rental, not ownable, and property in the county is still extremely cheap relative to rental rates).
They could replace the car bridges with train bridges or dedicated bus bridges (after knocking down a lot of houses, which if history repeats itself will be minority-owned houses), but this is a city with a small downtown and uptown where residents have always lived in the suburbs ever since the industrial revolution, well before ubiquitous car ownership.
Residents were using bridges to get to work in the days they walked there. There's sort of a lower bound on how many bridges a city of this geography will have.
> The people driving in from the suburbs are who work in the city.
This is true but that doesn't mean that the city should go broke catering to their whims — that could be putting tolls on the bridges, encouraging use of transit, etc. but they need some way to balance the budget.
> They could replace the car bridges with train bridges or dedicated bus bridges (after knocking down a lot of houses, which if history repeats itself will be minority-owned houses)
… or simply dedicate a lane for transit. It's not an iron law that the least efficient mode of transportation be given the highest priority.
An awful lot of these bridges started as footpaths and ox-cart turnpikes.
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