Why is AI Pathfinding so broken and terrible?

[Norfolk_Chris]

Not all changes can be made after the start of a map. For Example the population or private car ownership or the time setting is not changeable after starting a map. But everything that has to do specific with the vehicles and the stops/depots can be changed afterwards.

You can change the city population % setting in the ruleset editor, but I don't know what effect that will have on an existing saved city? I would be interesting to try this, it could easily checked by looking at a specific buildings capacity before and after the change, but remember that the city population may takes some time to take effect.
You can also change the % car ownership in the ruleset editor. But, remember that this setting is not the master car ownership setting, that is set in the map editor by changing 'Car Factor', you obviously cannot change this after you have started the city. The ruleset setting is a tweek on the master setting.