Question:
When a 1'-6" curb and gutter element is drawn in the xsc files produced by Roadway, it doesn't match the standard as
shown in the Standard Drawings, 846.01, sheet 1 of 3. In the Standard, the gutter pan is parallel to the bottom of
the curb and gutter. But in the xsc files we get from Roadway, the gutter pan will be sloped and not parallel to the
bottom.
Which is it supposed to be?
The problem arises if the hydraulic engineer is determining "spread" of stormwater on the pavement and including
the "drop" in the gutter when the "drop" isn't actually there. Also, the determination for the "top of grate"
elevation for drop inlets won't be correct.
Answer:
What is discussed here is the 4% rollover at the EOT to the gutter pan. The difference at the gutter's flow point
elevation can be as significant as 0.03' (0.36").
Discussing the drawing standards for 1'-6" curb and gutter over with Plans and Standards Management, it is agreed
that our Criteria will not apply any rollovers for 1'-6" curb and gutters. The gutter slope as well as the base
slope will both be the same as the roadway pavement superelevation rate.
NC DOT
NC DOH
NC GOV
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