2010 ADA Standards for Accessible Design Pocket Guide
126.96.36.199 Horizontal Dispersion.
EXCEPTIONS: 1. Horizontal dispersion shall not be required in assembly areas with 300 or fewer seats if the companion seats required by 221.3 and wheelchair spaces are located within the 2nd or 3rd quartile of the total row length. Intermediate aisles shall be included in determining the total row length. If the row length in the 2nd and 3rd quartile of a row is insufficient to accommodate the required number of companion seats and wheelchair spaces, the additional companion seats and wheelchair spaces shall be permitted to be located in the 1st and 4th quartile of the row. [S.H. 4.33.3]
2. In row seating, two wheelchair spaces shall be permitted to be located side-by-side.
Advisory 188.8.131.52 Horizontal Dispersion. Horizontal dispersion of wheelchair spaces is the placement of spaces in an assembly facility seating area from side-to-side or, in the case of an arena or stadium, around the field of play or performance area.