A few years ago me and a mate did LEJOG. We did it in 7 days, but really should have taken a few days longer, but we just didn’t have the time to do so. In the end we had to average well over 130miles a day, so long days in saddle.
We found was being on a tight schedule meant we couldn’t take a lot of the nice quiet county roads and alternative routes as it just added too much time, as they were usually hillier and longer. So we used a lot of main roads at times, as it was quicker and usually less issues with navigation. So by the time we got that far north, the A9 wasn’t as bad as some of the other roads we’d encountered in England.
We rode most of the A9 from Dunkeld to Latheron. We used the cycle path for lots of the sections south of Inverness where there was one, but some bits you had to be on the A9. These bits were pretty scary with the amount of traffic and the speed they go past, and wouldn’t like to do it again.
Most of the A9 after Inverness wasn’t too bad. I would say a lot of the road is decent size so plenty of room for traffic to overtake safely, so it didn’t feel too bad at all.
Given the chance to do LEJOG again I certainly would, but I would take longer and do it on much quieter roads and avoid the A9 where possible.
But I can totally understand why some use the A9, especially when they are on a tight time frame as it’s often the quickest route.