They'll always keep coming back, but you've got to fight them on the beaches, etc.
Thus everybody that is smart and fast enough just drives on the street (which isn't illegal by the way even if there is a dedicated cycle lane, it's just you have to tell this to angry car drivers some times).
Does Berlin remove the blue signs as required by law now? If not, technically cycle tracks fitted with them are still benutzungspflichtig, it's just that the Amtsentscheid that is behind their presence will be rechtswidrig (I'm probably using these legal terms completely wrongly, so German lawyers may well have to correct them, but that's how I understand them). As far as I know, few transport authorities have actually implemented the very clear directives set down in the judgement by the Bundesverwaltungsgericht in November 2010:
Hm, I thought there was a further elaboration of that in January 2011, but I can't find it now.
For instance, in Mainz the blue signs are still up almost everywhere, even though the traffic head honcho promised years ago that they'd be removed everywhere except on a de facto urban motorway.
Long story short: yes, you have to use the cycle lane when there's the blue sign.
You may choose freely to drive on the street or the cycle lane when there is no sign.
In Berlin about 85% of cycle lanes are without sign.
There are similar mixes of rubbish cycle facilities in Britain all over the place; you may not have seen Crap Cycle Lanes:
http://wcc.crankfoot.xyz/facility-of-the-month/
They'll always keep coming back, but you've got to fight them on the beaches, etc.
Does Berlin remove the blue signs as required by law now? If not, technically cycle tracks fitted with them are still benutzungspflichtig, it's just that the Amtsentscheid that is behind their presence will be rechtswidrig (I'm probably using these legal terms completely wrongly, so German lawyers may well have to correct them, but that's how I understand them). As far as I know, few transport authorities have actually implemented the very clear directives set down in the judgement by the Bundesverwaltungsgericht in November 2010:
https://www.bverwg.de/181110U3C42.09.0
Hm, I thought there was a further elaboration of that in January 2011, but I can't find it now.
For instance, in Mainz the blue signs are still up almost everywhere, even though the traffic head honcho promised years ago that they'd be removed everywhere except on a de facto urban motorway.