Conflicts due to work projects

One of the simplest cases of conflict in rail operations is a double-track line on which one track is out of service for a work project, often between two sets of crossovers.

(A crossover is a set of two turnouts and a connecting track that let a train pass from one main track to another.)

Inbound S-Bahn track out of service

Another variant on this theme was the situaton between Killwangen-Spreitenbach and Dietikon in late 2000 and early 2001, when one of the four tracks - the inbound track for suburban (S-Bahn) trains - was being rebuilt, and all inbound trains had to be routed over what in the future will be the inbound express track.

This was normally not too difficult, however, because the 2000-2001 schedule had been designed with the assumption that only the one track would be available. This had always been the case until late 2000, when third and fourth main tracks were put into service between Killwangen and Dietikon.

One-track tunnel

A frequent reason for taking tracks of service for long periods is maintenance work in tunnels. Such situations are more frequent today than in the past because budget pressures have forced SBB to do more such work during the day, when it is cheaper, than at night, when far fewer trains are running and it is easier to take a section of line completely out of service for a few hours.

For example, as of February 2000, due to work in the tunnel between Effingen and Schinznach Dorf on the Basel-Brugg line, the south track through the tunnel was out of service, and all trains in both directions had use the north track.

This meant that the Zurich dispatcher responsible for this section had to decide - in consultation with an operator at the Brugg traffic control center - how to resolve each conflict. A conflict was each case in which trains were approaching the tunnel from both directions and one would suffer a delay if the other went through first.