How do I calculate the average slope of a curved street or sidewalk shape?

Note:
CGA stands for Computer Generated Architecture, a scripting language specific to Esri CityEngine and used to generate 3D content. See the link to the 'Basics of Rule-based Modeling' in the Related Information section below.

Code:
approxCurvedSlope = asin (scope.sy / geometry.du(0,unitSpace) ) 
Street -->
    alignScopeToAxes(y)
    print ( approxCurvedSlope )

Note:
Please note that this is example code and may not be useful in all situations.