Citymapper has a mobility index that describes the percentage of people using local transit in several regions, compared to pre-pandemic data.
There appears to have been an enormous increase of local transit usage in the Rhine-Ruhr region in the last weekend, with almost twice as many people using public transportation last Saturday than before the pandemic.
There is a similar spike for Hamburg (136% last Saturday), but there were days in which their index rose close to 100% (e.g. August 4, with 85%), while there was no such activity for Rhein-Ruhr since March