I enjoyed wasting a lot of time playing the original version of SimCity. It simply but reasonably modeled the basic problems in city planning. As my town’s population grew, roads got so congested that commerce started to fail. So, like a good planner should, I would build transit lines.
Using cheat codes to give my plans an essentially unlimited pile of tax revenue to spend, I built block upon block of high-density buildings. Eventually, all the roads were replaced by transit lines. That allowed further increases in density, but, eventually, even the transit lines were choked by all the demand for traffic.
What I saw on my computer screen in 1990 is happening to Boston today: