The Lukeville border crossing (US-Mexico) apparently has a US exit checkpoint, which is a huge advantage for foreign visitors, as their exits need to be electronically recorded.
(for those who don't know, the US doesn't do border control on exit in general, and a US exit stamp doesn't exist)
What other crossings, if any, have this facility? Particularly at the Mexican border, since when entering Canada, the information is transmitted by Canada to the US anyway.