Thanks - interesting. I know traffic pattern/flow models and studies can be extremely complex. However, from the perspective of a 'dumb' commuter, it seems like the investment in smarter traffic signals would be offset by global savings from/economic benefits of reduced congestion (e.g. idle bus transit fuel/maintenance savings or generally increased standard of living and economic imprivements due to increased traffic flow).
It is useful to talk about both inefficiency (the thing you point out) and exploitability (the ability for any individual actor to make useful amounts of money out of fixing the inefficiency.)
Unless an area is both inefficient and exploitable, it is plausible that it will go unfixed for a long time.
When you start viewing it in those terms, you find obvious inefficiencies everywhere.
