7am, line starts forming around then, by 7:30/7:45am, there is a significant line. But if you're able to have access to a computer an Internet and you are open to an afternoon appointment, the online appointment scheduling opens at 7am. You schedule your appointment, you may get an afternoon time, but a very minimal wait. It was worth it for me than standing in a line for 1-2 hours!
Can you do what ever you need online? Check first. http://www.dps.texas.gov/DriverLicense/OnlineServices.htm
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