Special-Purpose 2D B-spline Tools
These tools in the Create Curves toolbox are used to place the following special types of 2D B-spline curves.
The Conic Curve tool is used to place a conic section — a hyperbola, parabola, or partial ellipse.
![](GUID-74A68830-29DA-A896-1B78-B8022990736A-low.png)
The Spiral Curve tool is used to place a transitional spiral — this is most commonly used for highway design.
![](GUID-0034C46A-12BE-8082-1CB0-511A99446B92-low.png)
The Interpolation by Arcs tool is used to place a complex chain of arcs that passes through a given set of points.
![](GUID-15FF0D77-059A-5FD9-2327-A20A2185CE22-low.png)