The Tvärbanan line opened in 2000 – a direct link between the west and south of the city which is also coordinated with the underground. Stockholm’s new tram system connects commuter trains, the underground and buses.

The Tvärbanan’s modern, silent and energy-efficient vehicles are a cross between a tram and a train. In the first project, Cactus was chosen to supply the traffic control system. The project took more than two years.


Traffic management and monitoring of punctuality

The system handles and monitors all the traffic management including punctuality. The system retrieves timetables from SL’s timetable database. The Cactus system also generates a lot of reports to monitor punctuality and infrastructure. The redundant architecture of the system guarantees maximum availability.


All events on replay

The operators can see what is going on and what disruptions may be expected. They can see variations and differences before problems occur. They can intervene in good time and prevent disruptions. It is not enough to make the right decision – action must be taken at the right time.

All events can be replayed afterwards in the Cactus system. That means that the staff can go back and analyse events like stoppages, alarms and other incidents in their own good time. All the history is collected and archived.


Part tramway

On the sections of the Tvärbanan that are classified as a tramway, SL uses AVI – a special kind of detection that indicates the position of the vehicles on the track. Each vehicle has its own ID which is read off at fixed positions. Other sections use modern computer-based signal interlockings.

On the Tvärbanan, the Cactus system also gathers information on input to the air lines along the track. The operators can see immediately if any section has a problem with the power supply.



The Tvärbanan is seen as passenger-friendly and has become very popular. The Cactus system forwards information from the traffic monitoring system to the overall passenger information system. Travellers then receive immediate details of any delays or hold-ups.