On Monday I cycled to Edinburgh and then back to Glasgow, on my trusty road rat. For the most part I used the National Cycling Network route 75. I have had a mixed time with the Sustrans routes. They make for interesting rides for the most part, and offer a good guide for long distance commuting (I had a *big* timbuk 2 of stuff to take with me and bring back) but they are exasperating sometimes too.
I lost the route a total of 5 times. Of these, I was able to re-find the route 3 times. Unfortunately, when it really mattered, after 9+ hours of riding with a heavy bag, on a 48:18 into the teeth of a very strong headwind (the weather was 'challenging' on Monday to say the least: the reason I had not run to the hills...) and I had been riding (with no lights as I had forgotten them) for 4 hours in total darkness.
It was very pleasant riding past Hillend Loch with a full moon, and then as I came into Airdrie, bam, the route came out onto a road in a new development of housing and it just disappeared. Obviously I didn't want to do the last 15+ miles on busy dual carriageways, in the heavy rain, with a gusting strong headwind and a heavy bag and no lights, so I spent 30mins looking for the route. I went down every side street and did several laps of the area looking for where it restarted. Nope.
Of course, if I had a route guide it might have helped. But I'm not stupid, its should have been slightly more obvious where it went. Ach well...
11 hours on the bike: 120+ miles with the first 60 taking 3.5 hours and the rest, well, the rest. Yep, it was a strong wind.