24hrs
Not sure I have a sentri pass so for me there is no wait. But for me personally before I had sentri I wait 15 to 20 minutes coming back to US. Going into Mexico I would say it's about 5 minute walk. The Border is open 24hrs. Just don't forget get your Passport. Hope that answers your question.
From U.S. to Mexico, extremely fast unless there is an American federal holiday like Thanksgiving. Then you would wait 30 minutes maximum to go to Mexico. Though I am a Mexican national so I don't declare anything nor I seek any papers from Mexican officials as an American. Still, I say Americans don't wait much either unless they're declaring a lot of things like crossborder businessmen and logistics experts do.
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