Tks for the tips.
I think it works well in theory when residential buildings can be re-positioned to avoid traffic jam.
However, the amount of simoleons saved from not upgrading road is much less than the simoleons that you have to spend for more service building (fire, police, park, ...) when your residential buildings are re-positioned to another location.
Eventually, all your houses will be skycrappers someday and a lot of service coming up like clinic, gamble, bus, entertainment, .... road upgrade is unavoidable.
Try out my guide
https://docs.google.com/spreadsheets/d/1HFpLdIXVlv3pHiOhQJzeJd7L0QqhPPol32h79yASois/edit?usp=sharing
