Brunette Girl Wearing Erotic Outfit On The Stairs With Iron Handrails

The 1992 Americans With Disabilities Act Accessibility Guidelines (ADAAG) stated that there was to be an absolute dimension of 1½" between a handrail and a wall. This was actually a "grab bar" dimension which was part of the 1986 ANSI A117.1. ANSI changed the notation to 1½" minimum in 1990. This was not corrected in ADAAG until 2004 which now calls for a 1½" (38 mm) clearance.
Codes also generally require that there be a 1½" clearance between the underside of the handrail and any obstruction -- including the horizontal bracket arm. There is an allowance however for variations in the handrail size -- for every 1/2" of additional perimeter dimension over 4", 1/8" may be subtracted from the clearance requirement.