2010 ADA Standards for Accessible Design Pocket Guide
409.3.1 Power Operation.
Elevator car and hoistway doors and gates shall be power operated and shall comply with ANSI/BHMA A156.19 (1997 or 2002 edition) (incorporated by reference, see “Referenced Standards” in Chapter 1). Power operated doors and gates shall remain open for 20 seconds minimum when activated.
EXCEPTION: In elevator cars with more than one opening, hoistway doors and gates shall be permitted to be of the manual-open, self-close type.