Recently the S-Bahn in Munich has been suffering from very poor punctuality, mainly due to holdups in the Stammstrecke. Whilst this is far from uncommon, there is in fact an additional reason, and rather banal at that.
As it happens, the Eisenbahn-Bundesamt (Federal Railway Authority) imposed stricter standards on the braking systems of trains, to counter the problem of some trains skidding on leaves when braking (it's beginning to sound like 'Leaves on the line', a classic excuse in the UK). The Munich S-Bahn could not meet the new standards and was forced to bring in restrictions on speed limits and increase the gap between trains, which both delays them and leaves too many trains trying to get through the same Stammstrecke tunnel in too short a space of time.
Whilst Die Bahn have not ruled out appealing the ruling (both on the grounds that it is an artificial limit introduced at the stroke of a pen, and that the supposedly better braking systems in use elsewhere have not improved safety), they have now decided to formalise the re-routing and cancellation of trains that has been happening ad-hoc for the last few weeks.
The main trains affected are the S2 and S5 'Taktverstärker' (the extra ones every 10 min) and the S7.
S-Bahn-Muenchen Link to details (German pdf)
Incidentally, the same Eisenbahn-Bundesamt has also forced new standards for the S-Bahn doors, where an infra-red 'mesh' will be introduced, rather than the simple infra-red 'beam' currently in use, which has been shown not to prevent people getting trapped in the doors.
