CBTC Systems

With the growing urbanization of societies and the need for mobility, urban transport systems have had to cope with a spectacular increase in demand. Environmental constraints limiting the use of cars have accentuated this. In Shanghai in 1990, there were no metro lines. By 2021, there will be 19! In Paris, the decision to build lines 15 to 18 has boosted network expansion. At the same time, network modernization has always been ongoing, with a particular focus on signalling systems, as they help to keep traffic flowing smoothly while ensuring safety. Technical solutions must therefore equip new installations and enable the renovation of existing ones.

From the 1980s onwards, transportation systems were faced with their first revolution: the introduction of software into equipment. This first step paved the way for a refinement of functional requirements. The second stage is linked to the telecommunications revolution: systems have moved from an architecture with point-to-point communications between equipment to one organized around a network, including the mobility of some of the equipment: trains are mobile! For urban signalling, this was the birth of CBTC (Communication Based Train Control) in the early 2000s.

However, signalling is a field in which developments are traditionally slow. A balance has therefore had to be struck between innovations that take advantage of the new technologies available to enhance services and performance, and the growing maturity of these new systems.