When I fume about border delays, which is to say every time I go to Canada, I focus on the delays for people crossing the border, but the costs associated with delays on the movement of goods are likely to be much larger in the aggregate.
I would note, as I often do in conversation, that the Europeans have done much better than we have on this dimension. Crossing from Germany into France, two countries that have fought three majors wars in the last 150 years and, truth be told, still don't really like (or, what is not unrelated, understand) each other very much, one does not have to stop at all. I've done it. You just drive right by some rusting remains of a border crossing station.
In contrast, Canada and the US, probably the two most similar separate countries on earth, who have not fought a war in 199 years, with integrated telecommunications and energy systems, still subject their residents, and their goods, to long delays, inane border questioning and, in the case of goods, heaps of bureaucracy on top of it. We can and should do better.
As an aside, estimating the costs on individual travelers would make a fine paper, too.