2019 California Standards for Accessible Design Guide (effective January 1, 2020 with July 1, 2021 amendments)

SECTION 1131A CHANGES IN LEVEL ON ACCESSIBLE ROUTES

1131A.1 Changes in level not exceeding ½ inch.

Abrupt changes in level along any accessible route shall not exceed ½ inch (12.7 mm). When changes in level do occur, they shall be beveled with a slope no greater than 1 unit vertical in 2 units horizontal (50-percent slope). Changes in level not exceeding ¼ inch (6.35 mm) may be vertical.

1131A.2 Changes greater than ½ inch.

Changes in level greater than ½ inch (12.7 mm) shall be made by means of a sloped surface not greater than 1 unit vertical in 20 units horizontal (5-percent slope), or a ramp, elevator or platform (wheelchair) lift. See Section 1122A for ramps and Section 1124A.11 for platform (wheelchair) lifts.