How to make concentric circle roads?

First, create a circle road using the circle shape.

After that, SimCity will display guidelines in circles above and below the road. Switch to the curved road tool, and then draw the inner circle by following the inner guidelines.

Start with two straight roads that intersect at right angles.

Choose a start point on one road and an endpoint on the other road that is the same distance from the intersection. Click on the start point, drag toward the intersection, and end on the end point. That circle will be centered on the intersection.

Repeat at different distances from the intersection.