Transverse slope The side-to-side pitch of a sidewalk, running from the building line toward the curb, required so water drains off the surface rather than pooling.
DOT specifications call for a transverse slope of roughly one to three inches of drop per five feet of width, and a flag that doesn't drain toward the curb, that retains water, or that exceeds this range can itself be cited as a substantial defect under Administrative Code § 19-152. Getting this pitch right is one of the more common failure points in amateur or non-compliant repairs, since a flag can look perfectly flat and still fail inspection if its slope is off. Proper transverse slope also matters for ADA accessibility, since excessive cross slope makes a route harder to navigate for wheelchair users.
Frequently Asked Questions About Transverse slope
What is transverse slope on a sidewalk?
The side-to-side pitch running from the building line toward the curb, required so water drains off the surface instead of pooling.
How much slope does NYC require?
DOT specifies a consistent pitch toward the curb, commonly cited as roughly one to three inches of fall across a five-foot width. Confirm the current DOT standard detail before construction.
Can slope alone cause a violation?
Yes. A flag that does not drain toward the curb, retains water, or falls outside the specified range can be cited under 19-152 even with no cracking.
How does slope affect accessibility?
Excessive cross slope makes a route difficult for wheelchair users. ADA accessible routes generally limit cross slope to 2 percent, about a quarter inch per foot.
Why do amateur repairs fail on slope?
Because a flag can look perfectly flat and still fail inspection. Pitch has to be set deliberately during forming and finishing.