I thought this was a fact of all famous and suitably large bridges like the Sydney harbour and Forth bridges. Because painting doesn’t effect the running of the bridge much they just hire enough painters that gets the bridge painted in time and then start again. Apparently the Forth bridge now uses a new paint that means it doesn’t need to be painted for 20 years though

Seeing the signs near the Golden Gate Bridge about how it's painted (EDIT: like a decade ago) made me think that it'd be a good idea to use drones to paint it. I explored that idea a bit deeper but it never went anywhere. There are/were some attempts at painting drones. I still think it'd be cool and could be made to work ;)