Problem is that the Federal Highway Association only spends for new projects, not routine maintenance (please check me on that though).
Therefore cities who need maintenance done will bundle routine maintenance they can't afford with expansion (lane expansion, streamlining). This lets them access federal dollars they wouldn't otherwise get.
Over decades, this has created a lot of infrastructure that isn't financially responsible as stuff has just gotten built and built and built. The ASCE (American Society of Civil Engineers) always grades the overall US as a "C" or worse for maintenance.
Part of the problem is that building things is sexy, maintaining them is harder and not sexy. Lotta money and focus on new stuff, maintenance is a secondary concern.