Creating a Terrain Model from Multiple Corridors

I am attampting to create a terrain model from several corridors.  The location is in an area where several ramps converge and would like to use the terrain model to define the detailed grading that a simple corridor can not produce.

What is the preferred method for something like this?  Is the terrain model even considered the best practice here?

If I import various features from the corridor they come in as a whole entity which is much longer than what I need.  Also, these features can not be modified in any way to trim them to the desired length.

I have thought about making horz. and vert. geometry along the desired features but this seems labor intensive.

Marc

Inroads 674