# Minimum curb height for detectable warning?



## nealderidder (Oct 12, 2016)

Good afternoon,

I've got a situation where I'm using a curb as a warning bewtween an accessible path and a drive aisle. No problem there, we do it all the time.

But how low can I make that curb? If I go down to four inches I've got significanlty less grading. I wouldn't go less than four.  I don't see any code provision keeping me to 6" min., am i missing something obvious?

Thanks,
Neal


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## mark handler (Oct 12, 2016)

https://www.dot.state.mn.us/ada/pdf/curbramp.pdf
"..a minimum 3 in. curb height for a minimum 6 in. width is the minimum recommended dimensions to provide visually impaired users an indication they are leaving the sidewalk and entering the street..."


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## ADAguy (Oct 12, 2016)

Good one Mark, did dot derive that from the PROW studies?


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## nealderidder (Oct 12, 2016)

4" should work. Maybe I'll check the city's construction standards too...

Thanks Mark


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## ICE (Oct 12, 2016)

A curb ramp guideline that is 45 pages is so typical of ADA folly ......and the OP is going to see if the city has more.

Apparently there have been studies made on the topic.  I wonder if that spawned any think tanks.


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