The city of Nantes, which sits at the gateway between Brittany and the west coast of France, has long been a pioneer in the area of public transport. As early as 1985, when trams were seen by many as an outmoded form of transport, the city became the first in country to re-introduce trams and now has the third largest tram network in France – with 42 km of routes spread across three lines. At the time, the wholesale removal of tramlines from cities across Europe after the Second World War was still a recent memory and so this was a brave step.

The city, in the form of its transport authority SEMITAN (Société d’Économie Mixte des Transports en commun de l’Agglomération Nantaise), has also gone against the trend in other parts of Europe by increasing the degree of separation between its radio system and its passenger information and vehicle location system. It has, however, also shown itself to be leading the way in adopting a city-wide TETRA network, on which a wide variety of public services will operate their voice and data communications.

As in many cities, public transport usage has risen over recent years, driven by both an environmental and intelligent transport systems agenda and, more recently, by the economic downturn and the rising cost of fuel. With an estimated 120 million passengers having used the SEMITAN network in 2010, the operator was keen to:

• maximize usage of the existing bus and tram network;

• further improve the integration of the bus and tram networks;

• improve customer service, through improved security, traffic flow and visibility of its timetables.

Radio rollout

SEMITAN operated two separate passenger information/vehicle location systems for the bus and tram networks respectively, as well as a legacy analogue radio system which was inextricably linked to both systems. To ensure that all systems operated optimally, SEMITAN chose to initially install a radio system and then to implement a passenger information/vehicle location system later. The radio system’s objective was to ensure passenger safety and security, primarily through voice calls between drivers, on-street controllers and the control centre.

After a competitive tender, Sysoco was chosen to supply the radio system. This was initially designed to cater for the requirements of SEMITAN’s bus network, however the tram network was then added to the system shortly after completion, and a significant number of other municipal services are now also joining the system. Local police, refuse collection, street cleaning, parks services, road maintenance and parking are all services which could, eventually, use the TETRA network. The 12-site system was intended to cover the entire city and its suburbs, but is also designed to expand into the broader Nantes area. 

More than 400 vehicles are equipped with Sepura SRG3900 mobile radios, whilst the SEMITAN on-street controllers and maintenance staff have a fleet of 90 Sepura STP8000 handportable radios at their disposal. All the terminals are GPS-enabled.

Enhancing service

The radio system’s main uses are to ensure customer safety and to improve customer service. The TETRA network offers secure communications and excellent coverage across the Nantes area.

Sepura’s GPS feature enables accurate vehicle location, which is particularly relevant for the management of incidents and accidents. These are the major causes of interruption and disruption to customers’ journeys and so the use of the radio network to provide effective management of these situations is crucial.

The next stage for SEMITAN will be the implementation of a passenger information system which, whilst procured separately, will need to be closely integrated into the radio system. Currently, SEMITAN uses Sysoco’s multi-operator GEREBUS control and dispatch system with AVL services, but an eventual move to a fully-featured passenger information system is planned.

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