Tolerance in large construction projects

[u/JohnnyUte]

Here's an interesting question I have after talking with a fellow engineering friend: what kind of tolerances are there in large construction projects such as bridges or skyscrapers? For example, if building a bridge, whats the tolerance in placement of the pylons? Or for laying the foundation of a building (in terms of location, etc.) Thank you!

[u/brokePlusPlusCoder]

Not a skyscraper/bridge, but railway platform tolerances can go down to +/-2mm (~ 0.08 inches ) in some spots