openstreetmap/mapnik-stylesheets — pull request #7 by danstowell (2013-04-01 09:55:34+00:00)
Title: waterways: render tunnel=culvert like tunnel=yes (fixes #3341)

See https://trac.openstreetmap.org/ticket/3341 . I'm not a mapnik expert at all, just a mapper. I hope this change looks appropriate - thanks.