Problems will occur with icing on the ramp and sediment collection in the
recess area. You may also see that installers may place the fields to deep and
you would exceed the allowable vertical clearance in the ADA, which presents
its own set of problems. I would give them guidance to keep the installation
as specified and choose a product that would be resistant to snow removal
practices.

It seems that most people assume that the DW panels are set on a flat surface.
While in some cases this is true the vast majority are set on a slope so that
icing and trapped sediment are less of an issue than it is being made out.
Icing has alwys been an issue and will always be an issue. The domes are still
raised and are still felt underfoot as intended. Resistant to snow removal
means the domes will remain after plowing or after the snow blower goes over
it. Of course this only removes the snow as deep as the blade can reach, which
is the TOP of the domes.

Recessing the detectable warning would likely defeat its purpose, as well as
trapping sediment, icing, etc. Almost as bad is the idea of using snow plows
to clear curb ramp or other pedestrian facilities. Several snow states and
cities use small vehicles like street sweepers with a rotating heavy bristle
brush. It works well on detectable warnings and won't get caught on expansion
joints or sidewalk segments displaced by freeze-thaw heave.

I agree with Pete and Dennis that there would be problems with keeping a
recessed panel from simply filling up with ice, snow and debris, which would
make them non-existant for all practical purposes. And I agree with you that
recessing may make the domes less detectable.

However, I don't see anyone saying that a recessed panel would be non-compliant
as such. I raise the point because we see a lot of people saying "the regs
don't say I can't do it, so I will." And I don't see anything that directly or
indirectly prohibits the action you asked about. Others are going to have this
idea, too.

My thought was that the phrase "raised truncated domes" at least implies that
domes must be higher than the adjoining surface, but that seems like a thin
reed to cling to.

What we attempt to do, usually with some degree of success, is to have the top
portion of the DW panel set so that the Truncated dome is level with the walk
surface, and at the bottom ( closest to the street) we have the panel flush
with the walk surface, which means that the domes are slightly higher than the
walk. This should help with snow removal when the snow is pushed towards the
street, of course this is assuming most snow removal is done on a property by
property basis.

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to the adjacent area as suggested in the ADAAG (A4.29.2). This general formula
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While there are not many standards that are set doe DW's the height of the
domes above the pavement is one. If the panel is recessed thant hte ADA
requirement for the height of the dome would not be met