Hi there
I dare say Tony is right about the cobblestone over the asphalt, certainly in Nuremberg, however, I have mine displayed on the street bases supplied by JG miniatures - the 9 inch base board comprising tarmac road and flagged pavement for the facades - and they look **** fine IMHO.
Interesting to note as well, of course, the nickname the LAH were given in the early days - 'asphalt soldiers'. The road outside the Turkish embassy in Berlin was certainly asphalt - or tarmac - and a photo in one of the Osprey books on the Waffen SS, showing a march past of the LAH outside the Reich Chancellery in 1938, suggests that the road there was also asphalt rather than cobblestone.
Hope this helps