* Map rail yards simply, with one railroad segment along either edge of the yard's tracks.
* Map industrial spurs only if they cross drivable roads.
* Do not map '''every''' piece of parallel track, such as in sidings or yards, or industrial spurs that do not cross any roads. Your work may otherwise be seen as clutter
, much like mapping every parking lot row.
* Multiple parallel lines at crossings:
** At most crossings, there should be only one railroad segment mapped and no more than two parallel railroads mapped at any crossing.