<p><a href="http://blogs.esri.com/Support/photos/mapping_center_nov_2007/images/346/original.aspx" target="_blank"><img src="http://blogs.esri.com/Support/photos/mapping_center_nov_2007/images/346/secondarythumb.aspx" title="Example of a transit map" alt="Example of a transit map" align="left" border="0" hspace="5"></a>The illustration at left shows a map the Paris Metro system (RATP). 

The routes are depicted in a schematic view and this kind of map is challenging

to create because multiple routes may share the same path, for example multiple

bus routes along a single road or track. When this happens, the coincident

routes are offset in a fashion that makes it possible to understand the path

each route is taking. When using ArcMap and line features for the routes, the

coincident features draw on top of one another, making it difficult to

visualize.