Reformatted from Nicholas Cranes Cycling in Europe, except for the entries marked with a superscript ¹, which are derived from the authors own experience. Some of these are new entries; others are obtained by splitting regions.
Cranes book dates back to 1988. Some of the regions covered may have changed for the worse due to increased traffic, but eastern Europe compensates by being more welcoming.
The accessibility column evidently measures ease of access from the UK, and is any case too dated to be of much use.