From the commentary on the ADA in the Federal Register upon publication:
The title III rule
published in 2010 provided that on or after March 15, 2012, public
accommodations must generally use the 2010 Standards as the benchmark
for their ongoing obligation to remove architectural barriers in
existing facilities to the extent such compliance is readily
achievable. 28 CFR 36.304(d)
And now the actual federal law quoted:
§ 36.304 Removal of barriers.
(a) General. A public accommodation shall remove architectural barriers in existing facilities, including communication barriers that are structural in nature, where such removal is readily achievable, i.e., easily accomplishable and able to be carried out without much difficulty or expense.
(b) Examples. Examples of steps to remove barriers include, but are not limited to, the following actions—
(1) Installing ramps;
(2) Making curb cuts in sidewalks and entrances;
(3) Repositioning shelves;
(4) Rearranging tables, chairs, vending machines, display racks, and other furniture;
(5) Repositioning telephones;
(6) Adding raised markings on elevator control buttons;
(7) Installing flashing alarm lights;
(8) Widening doors;
(9) Installing offset hinges to widen doorways;
(10) Eliminating a turnstile or providing an alternative accessible path;
(11) Installing accessible door hardware;
(12) Installing grab bars in toilet stalls;
(13) Rearranging toilet partitions to increase maneuvering space;
(14) Insulating lavatory pipes under sinks to prevent burns;
(15) Installing a raised toilet seat;
(16) Installing a full-length bathroom mirror;
(17) Repositioning the paper towel dispenser in a bathroom;
(18) Creating designated accessible parking spaces;
(19) Installing an accessible paper cup dispenser at an existing inaccessible water fountain;
(20) Removing high pile, low density carpeting; or
(21) Installing vehicle hand controls.
© Priorities. A public accommodation is urged to take measures to comply with the barrier removal requirements of this section in accordance with the following order of priorities.
(1) First, a public accommodation should take measures to provide access to a place of public accommodation from public sidewalks, parking, or public transportation. These measures include, for example, installing an entrance ramp, widening entrances, and providing accessible parking spaces.
(2) Second, a public accommodation should take measures to provide access to those areas of a place of public accommodation where goods and services are made available to the public. These measures include, for example, adjusting the layout of display racks, rearranging tables, providing Brailled and raised character signage, widening doors, providing visual alarms, and installing ramps.
(3) Third, a public accommodation should take measures to provide access to restroom facilities. These measures include, for example, removal of obstructing furniture or vending machines, widening of doors, installation of ramps, providing accessible signage, widening of toilet stalls, and installation of grab bars.
(4) Fourth, a public accommodation should take any other measures necessary to provide access to the goods, services, facilities, privileges, advantages, or accommodations of a place of public accommodation.