I crossed into Switzerland last year and people were randomly stopped and had their documents checked - it wasn't a border where you queue for hours, you just d

I crossed into Switzerland last year and people were randomly stopped and had their documents checked - it wasn't a border where you queue for hours, you just drive through and some people are flagged down. Technically at an EU level you don't need to have any ID to cross a Schengen border, but some countries have laws requiring visitors to carry ID at all times. (And of course you won't be let onboard a commercial flight without valid ID)