Good question, don't ya think?
I hope that the DOT will require the Mexican truckers to follow the exact same regs that our truckers have to follow, carry the same or higher insurance that ours have to carry, that their trucks meet or exceed the same safety and equipment standards ours have to meet and that their drivers are licensed to the same or higher standards that ours have to be licensed to.
Note that none of those things have anything to do with smuggling illegal aliens, drugs or, God forbid, terrorists into the country. Have we given up on drugs, illegals and terrorists altogether? Apparently.