See this is my issue with letting sat navs do their own thing, and why the ability to completely manage your own route and upload it is priceless...
I want to do a quick 2 day trip in April/May, probably down to le Havre, so I picked a destination, and let the tomtom pick a winding route. Not far in to the route and it appears to want to take me down this road...
It's not the sat navs fault, but I do wish there was an option to 'stick to main roads' as I can see the winding road option taking you down lots of single track roads ignoring the perfectly paved road a few hundred metres away, which it in fact it has done in this case! This shortcut avoids the main road for no more than a mile or 2.