It is double track throughout and uses the SNCF right of way.  It is electrified at 25kv and I saw seven 5-module sets.  These are painted in the standard SNCF Transilien blue and the tariff system is SNCF.  Trains run at 6 minute intervals. 

It quickly became evident that this is more of a train than a tram.  The top speed is 100 kmph and the acceleration is impressive.  There right of way is completely fenced and stops are at established station platforms.  There is practically no gap between the train and the platform.

Signalling is of the tramway type with the vertical and horizontal lines of lights to denote go and stop respectively.  Although it is double track throughout there is a section of third track in the middle and there are frequent crossovers.  The track is ballasted.  There are many road crossings, all of which are equipped with traffic signals, but none of them have gates or barriers.  At some high traffic crossings the intersection has been turned into a form of traffic circle.  There are a number of non signalled pedestrian crossings but these may be fitted with a bell or other form of warning.

Stations are closely spaced for a railway but some distance apart for a tramway.  The service is effective and with trains running at six minute intervals it has the capacity to handle a lot of people.