If you're riding your bike from Trondheim towards Inderøya, you'll likely end up on one of these routes between Leksvik and Mosvik:
The upper road is the common choice, and it is as you would expect: A bit hilly, with good tarmac, and some traffic. Meanwhile, the low road is alluring: Close to the sea, certainly very little traffic, quaint and rural. Maybe with great views?
After riding the upper road last year, I tried the lower road this year. I decided this while on my bike, approaching Leksvik.
This is what the route is like:
You start on tarmac, and follow it until it ends. This makes crossroads easy: Just go where there is tarmac:
Then there is no more tarmac:
Some of the juctions appear very suddenly, on steep downhills turning into steep uphills. I think these were unmarked until recently, but now they have wooden signs saying Mosvik. Follow those.
Keep following the signs towards Mosvik:
So navigation is not really a problem. But should you ride this road? Probably not. Most of the path is through dense forest, blocking the ocean view. It's also incredibly hilly. There are no flat stretches for rest, you're always going up, or going down. The road changes from tarmac, to packed dirt, to very loose gravel. You will be slow and uncomfortable if you ride skinny tires. My tools rattled loose on the last descent:
But it was fun, so go anyway.
Some relevant links:
Visit Innherred says
The road is partly in poor condition, but fully passable by car in summer. It is narrow, steep and poorly paved, but an experience! The road is not suitable for motorhomes.
Syklende pensjonister say (translated)
The view is amazing from Kammavegen. We could see almost from Steinkjer to Trondheim. Beat that!!! But at what cost? We recommend no cyclist choose this road.
A woman who rode the length of Norway in 2008 says (translated)
I haven't experienced hills like this in my entire life.