Hundreds of tow truck drivers drove their rigs in solemn procession yesterday to honor Daniel J. Coady Jr., a fellow operator who was killed last Wednesday night as he was helping a driver at a crash scene on Interstate 495 in Andover.Some of the trucks followed the flatbed carrying Coady’s casket from Conte Funeral Home to the North Andover Mall, where another fleet of highway haulers spilled onto Route 114, before coming to a halt at St.