As an exercise (and I'm curious about your thoughts on this), I found the main routes between place=city within Czechia (didn't have time to include cities in adjacent countries, bear that in mind).
Here's the result [1] using the old colour scheme (motorway=blue, trunk=green, primary=red; with a little mistake: secondary=yellow). Top image uses the current classifications, and bottom image is the result if city-city routes are classified as trunks. Looks very similar to most other maps. Just by looking at it, it's quite obvious which is the main route between each pair of cities. As expected, the method also found out the best ways through and around Praha when going across it. This could also be slightly improved - for example, with little extra time, it is easier to recommend going through route 6 and then Karlovarská than through route 5 and Bucharova. I've checked the three small secondary segments using Street View. Their physical structure is quite good. If still considered undersirable, there are alternative main ways that increase the total time of travel very slightly. Not all routers agreed on taking them anyway. [1] https://i.imgur.com/qFGSveX.jpg _______________________________________________ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
