Drawing a Handicap Curb in Autocad

I haven't done any ADA ramps for a while now, but my workflow is quite similar to yours.  Alignment along the flowline, create a FG profile & profile view, then use featurelines and profiles to model the ramp.  I set the flowline alignment to a no display style, then create a featureline right on top of it that duplicates the alignment's horizontal data and the profile's vertical data.

I do use the site & featureline priority tools to organize the featurelines; the flowline featureline is the highest priority, no other edit to any featureline will affect it.  Next highest priority are the featurelines that define the ramp & landing, no lesser priority featureline can affect them.  Finally a couple featurelines on the existing sidewalks where I think the new work will tie in to the existing.  These also are set to the highest priority (obviously I don't want to accidentally edit the FL elevations representing the existing work).

For parallel ramps I do most of the work in the profile view.  I also project featurelines into the profile view as needed, especially for complex combination ramps, so I can see what's going on (see the image below for a complex combination ramp).  The critical part for a combination ramp is the profile along the back of walk, to get the outer ramps, the landings, and the inner connecting piece of sidewalk to all be compliant.  It's easiest to model this as a profile, using the profile geometry editor.

I use the bare minimum of featurelines to model the ramp, I used to go into detail for all the pieces of the flares, or the ped curbs, and so on, but the workload and complexity go up exponentially (see the image below for a complex combination ramp).  I don't model the actual depressed curb in all cases.

Next I create a small FG surface for the ramp(s), out to where the new work ties in to existing, and I label the grades and dimensions.  Then by editing the profiles and featurelines I can see the effect on the surface.  I'll have my workspace split into three viewports:  Profile view, plan view showing only featurelines, and an isometric view with the surface on to get an overall view of what's going on (that's a tip from Jeff Bartels and his Civil 3D Immersion blog).

We put a lot of thought and discussion into what to show on our plans, and determined that we will only show proposed grades, and except for flowline elevations at the quarter-deltas we will not show any other elevation information.  The contractors get all the slope information they need from the slope labels, and it's up to them to set their forms accordingly.  We do not stake any elevations other than along the flowline.

I work in a primitive drawing that is xref'd into the production plan, and I use a label style that displays on the final plan.  Generally the views are 1:5 scale so the plans are easy to read (our normal road & paving plans are 1:20).

I also created a custom label for featurelines that labels grade (%) and distance.  This is handy because of the 15-foot rule (if a ramp graded to 8.3% does not catch in 15 feet, the ramp may be made steeper in order to catch within 15 feet).

Finally we decided that all ramps are to be designed to a maximum grade of 7.5%, not the ADA max of 8.33%, and all landings are to be designed to 1.5%, not 2.0%.  Our state DOT also recommends this approach.

Some time back I built a spreadsheet to do a bunch of specific calculations for me.  For example, given two station/elevation points, it calculates the grade between them, given a station & a grade, it calculates the resulting elevation at a distance, etc.  It has about eight or ten specific calculators on it, but I don't use it very often any more.

We bid our curb ramps as square feet of concrete, just like sidewalks, whereas some other agencies bid them per each.  Our way allows the contractor to make modifications as needed to fit actual site conditions and get paid for any extra concrete required.  Our overlay program does 50 to 200 ramps per year, and we've not had problems with this.

Attached is a detail from a consultant-prepared plan done to our requirements.  It's a little cluttered, but there is enough information for the contractor to build the ramps, and also the contractor will understand where the ramp will be non-compliant due to existing site conditions ("Built to the maximum extent feasible").

One other thing we do is if we are upgrading ramps at a signalized intersection, we run empty conduit from the nearest signal junction box to a 12" x 12" knockout panel located where the future APS pushbuttons need to go.  Typically we upgrade ramps during one season, then upgrade the signal pushbuttons the next season, using different funding sources.  We've done several intersections this way and it's worked very well.  The signal contractor removes the knockout panel, installs the foundation for the pushbutton post, and connects the APS wiring to the controller using the new conduit.

Jeffrey Rivers
Win 10E 64-bit, Intel i7-3.7GHz, 32 GB
NVIDIA Quadro P4000
C3D 2018 V12.0.1386.0
2018.2 update

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Source: https://forums.autodesk.com/t5/civil-3d-forum/ada-curb-ramp-workflow/td-p/8546330

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