It would not feel like summer in Munich without huge construction projects everywhere, and for the second summer in a row the MVG (Münchner Verkehrsgesellschaft, or Transit Authority) has chosen to begin a major renovation during the busiest tourist months. The reason being it is better to make things difficult now when school is out and many inhabitants are on vacation.
Beginning Monday 22 July, the main stretch of the S-Bahn network between Pasing and the Ostbahnhof will be closed from 10:15 p.m. until 4:45 the following morning. Four color-coded phases of the renovations can be found here (in German only), which run intermittently from now until 20 December.
The official website lists the reasons for the renovations as providing a better fireproof system in the main tunnel, as well as building a new station at the Donnersbergerbrücke. We here at munichNOW will continue to keep you posted on developments.