There is a bug in the MapWriter engine that produces extraneous vertical and horizontal lines at certain zoom levels where the "way" is closed (such as a raceway, airport perimeter track, and certain road layouts). This revision of the Voluntary bundle includes themes that attempt to fix this bug for raceways, runways and taxiways and unclassified and tertiary roads, although they do introduce other minor artefacts for the roads.
These images illustrate the bug, followed by "corrected" ones:
Versions that leave the roads unfixed are also included in the zip for download, which are in the first post as always.
I have also updated teh Locus version to give smoother contour lines and added a minimum zoom for various roads to appear, so low zoom maps do not have strange bits of road forced to appear by hiking or cycling ways. (That will make sense if you know the bug!)