The B6480 is a road across the Lancashire/Yorkshire border that has grown up a bit since its creation in the mid-1930s (it was unclassified before) thanks to upgrades to the A65. As a result of this, let's start at the road's western end, on the A683 just west of Hornby.
This isn't a fast road, it twists and it turns and at night it is pitch black, so don't think this is any quicker than going up to the A687 and picking up the A65 from there. Most of the settlements on the road have 30mph speed limits, such as Wray, Wennington, and of course the Benthams. There is a random length of 50mph before the administrative boundary with North Yorkshire, and two low bridges make this route unsuitable for HGVs.
A 40mph limit connects High and Low Bentham, and the road then returns to its usual narrow rural nature before eventually meeting the A65 at the Clapham Bypass, marking the original eastern end of the road. A quick right-left dogleg then puts you onto the old A65 through the village, which is of course now part of our road. This length of the B6480 is very small so soon rejoins the main road before sharing the A65 for a good few miles and then suddenly branching off to the left towards Settle.
Settle has the hallmarks of being a horrendous bottleneck back in its prime, so the A65 bypass (which is nearly ruler-straight and has a very long length of S2+1) must have been tremendous relief. An indication of how the old road was once a trunk road is immediately obvious as it too has a short S2+1 section as it drops down the ridge into Giggleswick. Settle proper has a tight single-lane section past shops and is laden with tourists when the weather is nice as Malham Cove is accessible from here.
Continuing past the town centre, the B6480 then returns to semi-rural before slamming back into the A65 at a roundabout. That's really the end of the road, unless the Long Preston Bypass ever gets built, which may see this B road extended even further...!