Getting from campervan field to Shepton?

[robin]

Due to a few issues around number of drivers/ number of passengers/ being able to get toddler off site if needed over the weekend/ when campervans and cars can access the site etc... I'm going to need to run back from the campervan fields back to Shepton Mallet on the Tuesday evening in order to collect a car and drive that in to the site. Now it's only about 4 miles by the look of it following the roads going via Pilton village and along A361, but I seem to recall that there is no footpaths or much of a verge along that section but there will of course be lots of frustrated drivers. 

So, does anyone know if there are any footpaths between the campervan fields and the A37/ A361 junction that I could run along instead as the bits of path shown on here don't seem to completely link up?

http://www.openstreetmap.org/#map=15/51.1629/-2.5544