Don't know the answer to that. I started at Tully once many years ago and had to be there earlier because we were on Clay Walker's team and they wanted to do team photos before he had to go sing the national anthem. Every other time, we have always either started from the house or from a team start near I10 and Park Row. I know Katy is a very popular start, so if you don't want to be way at the back of the queue, I would suggest earlier rather than later...maybe aim for getting to the stadium by 90 minutes before the start time? Assuming stadium traffic and parking lines, that maybe gets you parked and setting up and hour before the start with plenty of time to gear up, wait in line for a portajohn and get a good spot in the lineup. Somebody who has actually started at Katy might have better advice, but for me, any extra time I spend trying to sleep in is usually wasted anyways due to anticipation, so you might as well aim to get there early to avoid any last minute stress before the start.