Asphalt Grade Breaks at Handicap Spaces

[wd43stp123]

What are your thoughts on grade breaks in asphalt paving? Where I work some people are saying performing a grade break immediately outside a handicap space going from 1.5% (in hc space) to 3% (outside hc space) results in the 3% grade getting feathered back into the space thus being ADA incomliant. Right now we are working with a client who wants a handicap space in front of their building with a 5% cross slope on the non-handicap parking space beside it. I am not convinced it can't be done. After all, the asphalt grade is determined by the ABC beneath it. It would seem to me that if you get the ABC where it needs to be grade-wise (<2% in HC space and 5% in adjacent space) the asphalt would follow right along. I understand there may be slight roll on the asphalt surface between the breaks but nothing horribly noticeable. I am only asking because I have been practicing for a while and never heard of this being an issue. I suspect select contractors have made a stand it cannot be done in an effort to get out of tearing up and relaying handicap spots that were not graded correctly. I am interested also because this client builds all over the US and it is likely this has been done before. I am cautious to say it cannot be done when they have done it multiple times before in other parts of the country. Thank you in advance.

 

[Twinkie]

I would typically only do an actual grade break with an AD of 1 or less. You are going from 2-5 seems a little excessive. But when it is all said and done, it can be built the way you are suggesting, and is not in conflict with the ADAAG.

 

[dicksewerrat]

Keep all the grade corrections outside the handicap area. It is hard to push a wheel chair on a side slope. If my wife sees one the other way, Look out for the ADA police. And bad publicity.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[Ron]

Just matching a desired grade is not the only issue. When you have a short, steep transition, constructability and quality of the finished product are concerns. Will you be able to get a small compactor in there to get adequate compaction in each layer of the pavement section? This will all likely be hand spread, not machine spread, so asphalt temperature will be an issue...can you maintain a high enough temperature in the asphalt to achieve proper compaction? What is the top size of the surface course aggregate? For such an application it should be as small as practicable for a structural layer to prevent raveling.

 

[TerryScan]

So, how about the real world scenario that the grade break is rounded. If one puts the PVI half of the vertical curve distance away from the space, the grade should be fine within the space. So, if the curve or break rounding is 10 ft long, one should be fine placing the PVI 5 ft. from the space.

 

[civilman72]

Not sure how set your client is on having a 5% cross-slope in the parking space directly adjacent to the ADA parking space, but I don't think it's realistic. The way TerryScan described it will give you the best finished product and address Ron's concerns described above. But this scenario results in the second space over from the handicap space having a true 5% cross-slope, not the first one.