Marko Mäkelä <marko.makela@iki.fi> writes:
Actually, we do have a mean: if there are multiple parallel tracks (each drawn as a separate way with railway=*), it is a major railway. It should be doable to merge adjacent ways at lower resolutions and sum the "weights" of the ways, to decide what to draw. A style file extension could be useful, to specify e.g., the following:
* draw individual railways at resolution 24 * merge parallel tracks to one and draw them at resolution 22..23 * merge parallel tracks to one and draw if count>1 at resolution 21 * merge parallel tracks to one and draw if count>3 at resolution 20
I don't think that works. Around me, there are many railroads that are single-track but go long distances. The 1950s or so USGS 1:250K topo maps are interesting; railroads are thick black lines, since they used to be very important. The right test is probably: do any long-distance routes use this way? But really we just need to tag through railroads vs yards and sidings, and have some way to combine double-track railroads at smaller scales.