I use to know how to do this flawlessly but stopped playing a for a bit and completely forgot so everytime I try to line up the roads symetrically, they look bad.

I was wondering if there was a science to this.

I use that one road laying mod that shows you the degrees of angles and precision angles.
I know that if you have the curve tool activated, extending a road out 5 units by 5 units will get you a 90degree road or vice versa.

@ViccyQ In the asset editor the highways attach to the grid. If youre looking for clean highways without downloading anything you can easily make your own puzzle pieces like this in the asset editor.

Can you please tell me or show me the method on how you achieved this? I would really like some clean looking Highways without the help of tons of mods. Thanks much.