Earlier this week, I was pinged by a colleague who was curious about a parameter in the MediaDepressedShoulderVert – it seems as if the paved shoulder links were defaulting to a slope of 5% and could not be changed in the properties of this subassembly. His customer wanted to change this slope, but simply could not find a way to do so. I scratched my head along with him and looked into it just a bit further, waded through the documentation that seemed pretty ambiguous (to me, at least) and then decided that I knew where I could find the answer. I went directly to the source – my good friend Nick Zeeben, QA Analyst for Autodesk.
Nick argued that the documentation was perfectly clear - it states the following:
The paved portions of the shoulders follow the slopes defined for the left and right inside shoulder slopes for the baseline alignment’s superelevation specifications. These slopes are applied inward from the inside edges of traveled ways. The unpaved portions of the shoulders are fixed at the given Unpaved Shoulder %Slope value.
OK, so you have to have superelevation for this to work, right? That’s what it says in the help file! My question to Nick was how to change it if the baseline alignment did not use superelevation. His answer was simple – create a superelevation entry without calculating superelevation. Huh? He explained that there simply needed to be an entry in the superelevation table that contained the desired values and everything would calculate correctly. Let’s say that we want our inside shoulder to be at 4% rather then the default of 5%. If we create our corridor as we normally would and have an alignment with no superelevation defined, then you will see in the following illustration that our inside shoulder slope is definitely set to 5%, which is not what we want.
To fix this problem, we have to specify superelevation data. To do this, simply select your alignment, right-click and select Alignment Properties. Next, select the Superelevation tab, which should be blank. To add a superelevation region, select the Add a Transition Station button as illustrated below:
You will be asked in the command line to specify a station along the alignment, so enter a station of 0 (this is the beginning station of my alignment, adjust your values accordingly.) Once the transition region is created, you can simply change the Inside Shoulder values for both the left and the right side to 4%, as shown below:
Once you enter this information, simply click OK and then rebuild your corridor. A quick check of our corridor through the View/Edit Corridor command shows the updated value of 4%.
Once the light bulb came on over my head and I understood it, it made perfect sense. Here’s hoping that it helps clear up for you as well!
Have a great weekend!
Note: Just before I posted this, I checked this site to see what type of formatting and post style that Brian and Justin were using – I wanted everything to look roughly the same. When I glanced at Brian’s last post, I thought “no WAY he could be writing about the same thing!” But it seems like we ended up choosing polar opposite topics to talk about – his on subassemblies that don’t use superelevation when he wants them to and mine about subassemblies that use superelevation when I don’t want them to. OK, I thought it was an odd coincidence ;)
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