Using Unity's navigation system for cars on roads

Hello,

I am trying to recreate cars travelling down roads (similar to the roads in Cities:Skylines, but on a smaller scale).

I am having trouble getting the cars to stick to their side of the road in two-way traffic. I have searched online for a solution or tutorial, but cannot find one.

Would you please be able to recommend a tutorial or guide on how to get car to travel down roads, so that they stay on the correct side of the road even when turning?

Thank you,

 

From what I know pathfinding on a navmesh might not really be a good idea for this.
When it comes to cars driving around, you might be better off to define splines for each road that also contain a reference to their connected roads (turns and aheads on crossroads etc) and making your cars follow those instead.
If you then make sure there's a spline on the road for each direction and provide some splines for making U-turns, you could get a pretty good basis.

 

When using nav meshes for simple roads and I do mean simple an invisible barrier down the middle of the road with a nav mesh obstacle applied will work. But this as I said is for simple layouts (grids).