2010 ADA Standards for Accessible Design Pocket Guide
607.7 Bathtub Enclosures.
Enclosures for bathtubs shall not obstruct controls, faucets, shower and spray units or obstruct transfer from wheelchairs onto bathtub seats or into bathtubs. Enclosures on bathtubs shall not have tracks installed on the rim of the open face of the bathtub. [S.H. 4.20.7]