§ 36.304 Removal of barriers., (d) Relationship to alterations requirements of subpart D of this part.

(2) (i) Safe harbor. Elements that have not been altered in existing facilities on or after March 15, 2012, and that comply with the corresponding technical and scoping specifications for those elements in the 1991 Standards are not required to be modified in order to comply with the requirements set forth in the 2010 Standards.

The 1991 ADA Standards, Section 4.6.4 Signage requires accessible parking signage to be located so that it is not obscured by vehicles parked in the space.

A4.6.4 Signage. Signs designating parking places for disabled people can be seen from a driver’s seat if the signs are mounted high enough above the ground and located at the front of a parking space. Source: 1991 ADA Standards for Accessible Design by U.S. Department of Justice.

Signage [4.6.4] page 33 The ADAAG Manual, a guide to the Americans with Disabilities Act Accessibility Guidelines Developed by the U.S. Architectural and Transportation Barriers Compliance Board, July 1998

“Accessible spaces must be designated by the access symbol, which can be mounted on walls, posts, or from garage ceilings so that it is not obscured by vehicles parked in the space. Recommendation: Since traffic codes often govern sign height, ADAAG does not specify a height for parking signs. A height of at least 60 inches (measured to the bottom edge) is generally advisable (taking care not to make the sign a protruding object), although a higher height is better for signs at van spaces.”

The 2010 ADA Standards, Section 502.6 requires parking signage to be located 60” minimum AFF or AFG to the bottom of the sign.

2010 ADA Standards, “502.6 Identification. Parking space identification signs shall include the International Symbol of Accessibility complying with 703.7.2.1. Signs identifying van parking spaces shall contain the designation “van accessible.” Signs shall be 60 inches (1525 mm) minimum above the finish floor or ground surface measured to the bottom of the sign.”

The question asked is “do parking signs that were installed before March 15, 2012, at a height to the bottom of the sign of less than 60” AFF qualify for a safe harbor?

To qualify for the safe harbor the signs would have to comply with the corresponding technical and scoping specifications for those elements in the 1991 Standards and be high enough "so they cannot be obscured by a vehicle parked in the space." Because there is no specific height noted in the 1991 ADA Standard, the owner and/or person responsible for the accessible features will be required to make sure that the signage is not obscured.

Because the 1991 ADA Standard may hold the owner responsible for determining if the  parking signage is obscured when the bottom of the signage is mounted below 60” AFF/AFG, it would be best to alter the signage and mount it at least 60” AFF/AFG to the bottom of the sign so that the height of the signage will not be an issue.

The 60" minimum under the ADA only applies to the signs required by the ADA. Signs not required by the ADA, such as penalty signs, are not covered by the ADA requirements for how to mount them.