PC gaming graphics question

[dal]

Hi, I've had a search online & can't seem to find anything out about this.
What I want to know is how are the graphics to road building games ( like cities skylines )
made.
I'm making a game & I've got a couple of splines to represent roads now I need to make the graphics / mesh for them, see photos :

So from this


I want to get somthing like this :



If you can point me in the right direction that would be a help.
I've googled :
how are road systems in games made
render road from spline
& a number of others.

 

[dal]

Thanks for the liink. I d be able to create a mesh from a spline it's the junction part im finding tricky

 

[dal]

Yes I'm anticipating the problem. The only way I can think this could be done is by creating a mesh from interpolations of the splines, but as you can see from the diagram below there would be a area where
the spline would overlap. I could place the yellow centre line slightly above the rest of the mesh but I think I'd still get problems with z fighting - although it might be worth a try to see.
The other option with this approach is to calculate where the quads will intersect the yellow line and only draw them down to there.

I'm still wondering how the hell do all those AAA game devs do this sort of thing, I'm sure this is not the only way to do it.

 

[dal]

Thanks for your reply, I'm considering both options. I've been thinking a lot about how to make a mesh around the road section since getting into game dev yes I would believe how much work goes into
what looks like something mundane.