Probably well-late in reply to the OP, but the Rannoch-Moor/Glencoe section was one of the best bits of my LEJOG. The 56mph free-wheel down the Glen to the sea was just awesome. No cars, no noise, just the whirr of tyres on tarmac, and the snow covered tops..... it was April/May, so perhaps too early for heavy traffic. Very memorable. I'd do the whole ride again just to repeat that experience (oh, and the stretch from Loch Naver, down Strath Naver to Bettyhill)....... hmm, I can see me doing this again in the next couple of years.....