Superelevation Diagram for Reverse and Compound Curves

[inhinyero]

How do I create superelevation diagrams for reverse and compound curves? If the tangent of 2 reverse curves are shorter than the minimum runout, how will I graph the diagram?

 

[Maury]

For reverse curves without a long enough tangent in between to allow for the superelevation runout, there is no good solution. Try reducing the posted speed to match the geometry you end up with. I've had to do this myself, and it's not a good feeling.

With compound curves, set the design speed and design criteria for the smaller radius. If there is a short tangent in between the two, carry the superelevation through it or do a partial transition.

 

[dragonyian]

If the design speed is low, and reverse curve is not avoidable due to site constraint, can try to distribute the transition equally to the both connecting curves