Speed is affected by process, and process evolves in reaction to abuse. In the beginning, it's quick to do everything, but as people take advantage - routing contracts to friends, taking safety shortcuts - rules get put into place and those rules affect the time to complete. For New York specifically there's another factor that it's strange the article omitted: Robert Moses. Prior to the mid-1960s, it was fairly simp…
Honestly this kind of reminds me how a large application grows. You get a polished application out and discover a bug, but you can't rewrite the whole app so you put a patch in. Then another bug is found, so another patch gets pushed out. Over time legitimate bugs and requirements at the time fall by the wayside but the code remains. I don't know how we fix that problem when it comes to legal code though.
However, there isn't much incentive for it. A law getting struck down has no negative effect on Congress or state legislatures. That's a problem IMO