This style is specifically made for printing in black and white at at least 150 dpi with a route overlayed. Contrast is high, labels are small and aplenty. You can see a demo at osmz.ru/veloroad.html, where you can compare the layer to other maps, and you can use the layer at openstreetmap.ru.
npm install -g carto git clone https://github.com/Zverik/veloroad.git veloroad cd veloroad ./get-shapefiles.sh carto -l project.mml > veloroad.xml
I use smoothed GMTED2010 relief maps for generating contours, because that way you don't get many anrtifacts (unlike SRTM). And it covers most of the planet, also unlike SRTM. Download Median/15 squares merge them, apply gaussian filter in SAGA and generate contours with GDAL:
gdal_merge 30N000E_20101117_gmted_med150.tif dem2.tif ... -o gmted_dem.tif saga_cmd libio_gdal 0 -GRIDS tmp1 -FILES gmted_dem.tif saga_cmd libgrid_filter 1 -INPUT tmp1.sgrd -RESULT tmp2 -RADIUS 2 saga_cmd libio_gdal 2 -GRIDS tmp2.sgrd -FILE gmted-new.tif gdal_contour -a ELEV -i 25 gmted-new.tif gmted-new-contours.shp shapeindex gmted-new-contours.shp
Traces are meant not to overlayed on top of the map, but included underneath labels in "route" layer. So yes, you should use Mapnik for rendering traces, produce a vector image and postprocess it with Inkscape, moving labels out of the way. Someday there will be a website for most of that, but for now please use mapnik-group-text and Nik4.
The style has "scale" layer, which should be configurable. In
project.mml there is an SQL with subquery with
coordinates and two numeric properties. You can change those, so the linear scale is drawn on the resulting map.
Author and license
The style was made by Ilya Zverev, published under WTFPL. Tiles at
tile.osmz.ru are published under CC-BY, you need
to add "Tiles © Ilya Zverev" to your copyright string (and for OSM, obviously).