2010 ADA Standards for Accessible Design Pocket Guide

802.2.1.2 Lines of Sight Between Heads.

Where spectators are provided lines of sight over the shoulders and between the heads of spectators seated in the first row in front of their seats, spectators seated in wheelchair spaces shall be afforded lines of sight over the shoulders and between the heads of seated spectators in the first row in front of wheelchair spaces. [S.H. 4.33.3]

Figure 802.2.1.2 Lines of Sight Between the Heads of Seated Spectators