Using the Design Criteria for Superelevation
Civil 3D 2009 has the ability to design superelevation in
roadways based on criteria set in our alignments. We are
going to take a look at these settings and also how they are
applied.

The design criteria for any alignment are held in the
alignment properties under the design criteria tab. This is
where we will begin to assign specifics.

Above you can see the contents of the design criteria tab.
This is where we will set up our design speed for the
alignment based on stations as you can see above. This is
also where we will specify our AASHTO criteria. For this
road we are going to go with a 6 percent super. We are going
to start at station 14+59.78 and work our way to the end of
the alignment.

Once we set up our design criteria we can move onto the
superelevation tab to actually compute our roadway data
based on the design criteria.

We can then compute our data in this tab by choosing the Set
Superelevation Properties button in the top left of the
dialog box.

It will then compute the superelevation data by using the
tangent and curve data and then display it in a dialog to
ensure that it is correct. Once we confirm our data and
select ok the superelevation tab is populated with our
information for our roadway design as seen below.

Once this information is tied to the alignment we can create
our roadway corridor and see the Superelevation take place.

Now we can use the view/edit corridor section to make sure
that our settings have been applied as seen below.

Above you can see that the Superelevation has been applied.
Civil 3D is a great tool for designing roadways. As you can
see above this is a very powerful and quick way to apply
superelevation data to a roadway. One of the main advantages
to using Civil 3D for this task is that all the dynamic
aspects of modeling in Civil 3D still apply, letting us move
through design changes quickly even with such complex data
applied.