Nearly 15% of journeys are by bike in Berlin and cycling is common in cities like Hamburg. Some small to medium sized cities, especially university towns like Greifswald, Erlangen or Münster have made a lot of progress in becoming more bike friendly and bicycle may well be the prime mode of inner-city transportation in these cities.
There are over 70,000 kilometers of routes in total. Some of the longer, more famous routes include:
As Germans like to have a Verein for almost anything there is one for cyclists as well, the ADFC, which can give you resources on bike safety, maintenance and maps for popular tours ranging from day trips to week-long holidays.
There is also a list of "bike friendly" hotels accredited and maintained by the ADFC. These hotels are happy to accommodate travellers with bicycles that are only staying one night, and can also provide resources such as bike-sheds, lunch-boxes and maps. The hotels usually display a sticker near the entrance to advertise this status.
Infrastructure between settlements is largely dependent on state politics, while infrastructure within cities and villages is mostly dependent on local politics, so bike trails run the gamut from well maintained smooth lines going to every major point of importance to a few lines drawn onto the pavement, which get all the snow from the car lanes dumped onto them in the winter. The ADFC and others are of course trying to remedy the situation where it is untenable, but cycling when it snows can be a challenge in many cities – thankfully studded tires are legal everywhere for bikes.
In the second half of the 2010s, cycling became a federal priority for the first time, largely fueled by the "Pedelec" (E-Bike) boom. Pedelecs are treated as bikes if their electric assistance switches off at 25 km/h – otherwise they count as motorbikes and aren't allowed on most cycle routes. While there have been large federal and state commitments towards new cycling infrastructure and "bicycle superhighways", as of 2017 little actual construction has come of this and many cities don't use the full budget allocated for cycling.