Mark Richardson did not blame his weight — 594 pounds as of September 2010 — on any underlying physiological disorder, U.S. District Judge John Robert Blakey recounted when ruling on cross motions for summary judgment in Richardson’s lawsuit against the Chicago Transit Authority for allegedly violating the Americans with Disabilities Act by terminating his employment as a bus driver based on his obesity.Among other things, Richardson had to present evidence he was “disabled,” which is defined …