There is a lot of point to them when towns are gridlocked. Yes, occasionally cars use the bus lane (whether this is intended or not, I like it, it’s realistic) but being stuck behind 1 car is better than being stuck behind 500.
The AI needs to use regular dual-lanes more efficiently too, I have a tailback stretching from one town to another where only 2 lanes of a 4 lane highway that I built are even being properly utilised.
http://cloud-4.steampowered.com/ugc/50986086026324861/AFFE12D31BDB41387D899CD0E0449CD78E4E6A20/
http://cloud-4.steampowered.com/ugc/50986086026330296/16DA9F52EB8AB53135A5EA3EE753ED7B4568AB88/