Every city planner in Cities Skylines starts with “grid” with 90° every mine town looks like this at starts. But what if you want build “curve roads” there are super quick guide how to curve roads.
Quick step by step:
- Open road buildings tab.
- Select “curve mode” in roads builder.
- Select “start” of curve.
- Select “center” of curve.
- Select “target of curve.
Selecting “curve mode” in roads builder
This mode you could find when you open road building. In default is selected “straight mode” you could change this settings to “curve mode” by clicking on icon bellow:

Select “start” of curve
In this mode are building of roads works in two steps. First is select to direction of start of route…

Select “center” of curve
… and the second step is the creation of the curve itself. You should view that you still have some guiding lines which will helps you building “smooth” curves.

Select “target” of curve
Of course you could build another curve road from other curve as I show you on images bellow. Best of this is that you could build unusual and more “realistic” residential zones…

Problems of building in curves inside Cities Skylines
… but this buildings had one big problem which developers of Cities Skylines completely missed. Zones do not relate to each other in this mode and between buildings which are builded in curve are spaces.

I would much prefer that the “grid” somehow adapt better to these buildings and create plots that relate to each other in some way. It would definitely look better.