Creating Handicap Ramps in your Corridors

Another week, another great guest post. Throw some feedback and tell us what you think of Mr. Risch’s post- JW

So a friend of mine and I were talking about different ways to incorporate handicap ramps into a surface. He’d mentioned he had some creative ideas about using/editing corridor sections and the next thing I knew he was calling me into his office to show me what he’d done. Check it out after the jump

As you can see by the graphic below, I’ve specified additional stations at the point where the curb is full height and where it becomes zero.


I then select View/Edit Corridor Sections and select the additional sections where the curb height becomes zero, wiping down the curb height from .5 to .01. I also change the UrbanSidewalk Inside Boulevard Width from 5.5’ to 0, the Sidewalk Width from 5’ to 8’ to simulate the full length of the ramp, and finally adjust the Slope from my default of 2% to 8.33%. This would be set to whatever you determine is necessary to reflect the slope of the handicap ramp.


Once those changes have been made, the next step is to delete all the Subassemblies making up any sections falling inside the limits of the ramp.


The last step is to flip faces of the TIN to match the ramp.


In Object Viewer we can see the handicap ramp built into the corridor model.


Once you’re comfortable with the process, each handicap ramp takes just a couple of minutes to complete, which isn’t too bad considering that it will remain dynamic to the corridor model.


  1. Jason Hickey says:

    I like the thinking there. Great post!

  2. Matt Kolberg says:

    I think this is a better solution than feature lines.

    Good ideas.


  3. Neil Wilson says:

    Forgive my ingnorance as I am still new to C3D. What would be involved to get the ramps back in position if the alignment were lengthened or shortened so that the stationing changed?

  4. Great question. I was just talking about this the other day.. “why are corridors/regions specified from stations instead of coordinates along the alignmenmt???”
    If an alignment stationing changes, you’ll need to update all your regions to match the new stationing, whereas if it were coordinate based, the station displays for each region would just change to reflect the new stationing at that location. Seems simple enough, but for now you’ll have to manually update the start and end station for each region if the alignments are lengthened or shortened.

  5. Neil Wilson says:

    What I am also wondering Matt is whether you would have to re-edit the sections for each ramp since the stations would now be in the wrong place. Would you have to undo the edits to the sections at the old stations and then re-apply them to the new stations? If so that would make for more work than it’s worth and feature lines or grading objects would be a more practical approach.

  6. If the alignment lengths or shortens, you can change the station values for the edited sections easily enough. It would be no different for your intersections, unless you built those with featurelines too.
    There will most likely be sections falling inside the limits of the ramp at the new station location, so you can delete those as described above.
    If the ramp is removed from the design completely, simply uncheck the override and the sections will return to normal.

  7. Neil Wilson says:

    That is good to know. Carry on!

  8. Joe Beverin says:

    I’ve got a curved street with ramps on each side at the ‘same’ station. I’m trying to envision whether this procedure will allow me to accurately model both ramps, because the starting stations and ending stations for a fixed-width ramp are different for the inside of the curve versus the outside. Any thoughts?

  9. I have a answer to the curved street with drive ramps on both sides. Multiple baselines. add a second baseline of the same alignment and specify the stations you need on each side of the road seperately. this would require half width assemblies for both sides of the road which isn’t hard.



  10. glenn depena says:

    Awesome… This is exactly what I needed. The only part I do not fully understand is how to erase subassembly parts in stations that fall within the driveway.