In the UK there are cycle paths laid down with proper tarmac just like the stuff they have on the roads. However, none of them that I have come across are level enough to afford a comfortable ride at speed.
I don't understand why it has to be this way, it is not as if cycle paths get dug up every five minutes like the roads do, there are no 40 tonne HGV's to break up the surface and the machines used to lay the tarmac are just like the ones they use on the road.
This is unfortunate given that most bikes do not have suspension, whereas all cars do.
What countries are there where they bother to lay cycle paths completely level? Why are the British ones never made nice and smooth? Do rough cycle paths discourage you from using them, in preference to staying on the road?
Edit:
Originally 'cycle lanes', I mean't 'cycle paths' - routes that are not necessarily adjacent to the road.