I recall now driving a rental car from Canada side into the US on Thousand Island Bridge at the other end of Lake Ontario. This must be around the late 90s, because we had our children with us on that trip and I could picture them and their age then.
The female border guard was about to wave us through, and when she saw us having our passports ready said "OK, as you have them out, I might as well look at them". As casual as that! Maybe she was joking.
Things have changed significantly since 9/11.
Things have dramatically changed. We used to ride our bikes and walk back and forth to Niagara Falls, NY over the bridges with no ID at all. At age 15!! I also used to walk and ride across the Bluewater bridge from Sarnia to Pt Huron, Michigan as a teen. The good old days!