When did New York start building slowly?
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 simple: if Robert Moses wanted something built, it was built.  If he wanted it blocked, it was blocked.  This made the process of getting approvals a known factor.  Moses chaired a wide variety of authorities including NYC Planning Commission, the Parks Department, and more.  He was the sole authority to negotiate with the Federal government for NYC projects.This kind of central oversight allows certain projects to be completed much faster than it would be in other setups, but it also allows for a number of bad outcomes - corruption, ignoring the public good, environmental destruction, and more.  As such, over time more process gets added.  It's easy to criticize process, but many of the rules were written in blood with the best of intentions.