So, the problem City now has a population of 216K and there are next to no traffic problems.
There are a few hundred students travelling at 6AM which can clog the roads up a bit, but these mostly disperse by about 8AM.
I accidentally placed my Fire Station incorrectly, resulting in a strange journey from its garage to any fire in the City so lost a couple of buildings before I realised, but other than that...
THANK YOU!!!!