It became apparent during travel planning that crossing border is non-trivial. In the end, I planned one day for each border crossing, with no other travel on that day.

I later found Ukrainian Customs Service maintains a web-site where they publish crossing delays, for Ukrainian side only, for passenger and cargo vehicles.

I made a little site which regularly scrapes that data, collects it, and publishes it.

Big thank-you as ever to Postgres and Gnuplot.

It is apparent that at least of the data, some of time, is likely not accurate. I don't know how they generate data. I suspect it's some guy sitting at a computer going "I think it's taking about this long now", but on the hand I also see minute-by-minute changes, which is too frequent for human input.

In any event, if the numbers for a given crossing look unreliable, then you can know taking that crossing is risky in the sense of you know you don't know what's really going on (and you might well be better off selecting a crossing which looks plausible).

Border crossings have a lot of reviews on Google Maps (although some could be fakes from hostile actors). The long delays (20 hours plus) for some crossings can be seen to have reviews describing the same experience.