Among the various exceptions are several tram systems, such as the ones in Bordeaux, Angers, Reims and Dubai that use a proprietary underground system developed by Alstom, called APS, which only applies power to segments of track that are completely covered by the tram.
The Chicago Transit Authority's Yellow Line used both third rail and pantograph collection, switching from the former to the latter at roughly halfway from Howard station towards the terminus at Dempster-Skokie station and vice versa.