Dear Glen :

The roadway geometry is dependent upon if your are doing a HEC-2 or HEC-RAS study. Lesson 4 in RiverCAD Manual Chapter 7 describes how to define a HEC-2 culvert and Lesson 5 in Chapter 7 describes how to define a HEC-RAS culvert.

Basically, HEC-2 requires the roadway geometry to be defined at the upstream face cross section, and HEC-RAS requires the roadway geometry to be defined at both the downstream and upstream face cross sections. To define the roadway geometry, select Input | Ground Geometry | Edit Geometry. The Edit Geometry dialog box allows you to define the roadway stationing and corresponding elevations.

If you have any additional questions or need any further information, please contact me again.

Sincerely,

Chris E. Maeder, M.S.
Senior Technical Engineer
chris.maeder@bossintl.com