The latest development release of scenProc makes a set of new steps to create terrain vector scenery generally available. This means that you can now use scenProc to make terrain vectors with the shp2vec tool.

The manual contains a sample script that shows you how you can make terrain vectors from OpenStreetMap data, but of course you can also tune this script to use the attributes of your vector data.

You can use this functionality for example to create freeway traffic BGL files for your scenery based on a road vector data.