The “old” train protection system in Switzerland was designed on the basis of a hazard analysis. In other words, additional safety precautions were taken at signalling points with a high hazard potential in order to monitor the train there with a braking curve (ZUB). All other points with low hazard potential are equipped with a caution/stop monitoring system (SIGNUM).

In order to achieve the goal of a uniform train protection and signalling system as economically as possible, Switzerland has equipped all existing lineside signalling points with the ETCS L1 Limited Supervision (LS) system as a migration solution. This made it possible to achieve the function of the “old” SIGNUM and ZUB systems using ETCS with a marginal impact on the safety level.

This measure allows vehicles equipped with ETCS to run on the entire normal-gauge network in Switzerland without a national automatic train protection system and enables technical interoperability.

ETCS Level 2 is a radio-based train protection system. Movement authority is displayed via cab signalling. Apart from a few indicator panels, lineside signalling (light signals) is not required.

Train detection and, therefore, train integrity supervision still remain in place trackside. All trains automatically report their exact position and direction of travel to the radio block centre (RBC) at regular intervals via the GSM-R (Global System for Mobile Communication – Railway) radio network. The movements of the trains are monitored by the radio block centre. The movement authority is continuously transmitted to the vehicle from the radio block centre via a radio system (currently GSM-R, to be replaced by the Future Railway Mobile Communication System (FRMCS)).

The Eurobalises are used as passive positioning beacons (electronic kilometre markers). Between two positioning beacons, the train determines its position via sensors (axle sensors, accelerometer and radar). The positioning beacons serve as reference points to correct any distance measurement errors. The on-board computer (European Vital Computer) continuously monitors the transmitted data and the maximum permissible speed.

In Switzerland, a distinction is made for ETCS Level 2 between conventional speed areas and advanced speed areas. The difference between the areas is that conventional speeds are those up to 160km/h and advanced speeds are those between 160km/h and 250km/h.

The ETCS Level 2 train protection system for advanced speed areas is used on the Rail 2000 Mattstetten–Rothrist route, in the Lötschberg Base Tunnel and in the Gotthard and Ceneri Base Tunnels. ETCS Level 2 for conventional speed areas is used, for example, on the Brunnen–Altdorf, Biasca–Castione, Lausanne–Villeneuve or Sion–Sierre routes.

ETCS Level 2 increases the safety of rail traffic compared to lineside signalling, contributes to timetable stability in the face of high train density and forms the basis for future operational interoperability. 

The long-term objective – as described by the Swiss Federal Office of Transport (BAV) in its ERTMS strategy – is to convert the entire normal-gauge network to ETCS L2. To this end, an implementation concept is being drawn up, which will serve as the basis for further migration steps.

In addition to the migration to ETCS Level 2, the railway communication network is to be converted from the current GSM-R system to the interoperable FRMCS (Future Railway Mobile Communication System) in the future.