The Electric Circuits option, which can be reach through the View > Electric Circuit menu, makes it possible to check for short circuits within a layout.
This feature is specifically aimed at users of 12 and 9 volt track. When using 12 or 9 volt track, any configuration that permits a train to reverse direction (such as a wye or reversing loop), will create a short circuit. When activated, this feature will mark the section of track which is causing the short circuit with an orange "Z".
Short circuits are no longer an issue when using RC and Power Function track as these do not have integrated powerlines.