Underground Rail Is the Best Option
The 2025 Ironman Triathlon takes place on Sunday, June 29, with disruptions to street traffic throughout the city due to closures of certain main boulevards as well as most streets in the city center. While the streets immediately around Holy Cross won't be closed, main thoroughfares leading into the neighborhood that will be cut off in the early morning Sunday include Friedberger Landstrasse and Hanauer Landstrasse. Tram line 12, which serves the Eissporthalle stop near Holy Cross, will be partly redirected and won't cross from the western end of the city, while Tram 14, which has its terminus at the nearby Ernst-May-Platz, won't run at all in the area.
Trains on the S-Bahn and U-Bahn underground lines won't be affected, and parishioners are advised to use those services to reach Holy Cross for the 9:30 a.m. Mass. The closest stop is Eissporthalle/Festplatz on the U7 line. See the RMV public-transport website's English page at https://www.rmv.de/c/en/homepage/frankfurt for routes & schedules and public broadcaster HR's website for detailed German-language information on street closures.