This is a lovely countryside route in Backwell, near Bristol Airport. There is space for one or two cars right outside Jubilee Nature Reserve on Backwell Hill Road, where this walk finishes. There is also space to park in a few lay-bys at the end of Long Lane, and you could pick up the route there (approximate postcode BS48 3BY).
This route will lead you across footpaths and by-ways, some of which are pretty muddy in winter. There are a couple of gorgeous big fields with no livestock in. There are a few small sections of walking on quiet roads, but no more than 5 mins at a time. When we walked (December), we only saw sheep and horses in a neighbouring field, but there was evidence of potential cows in one field towards the end, that could be avoided by continuing on the by-way instead, and one field with sheep poop in just after you walk through the farm. There is also a little bit that goes through someones garden, but it looked like you could detour round the footpath there to avoid it. There is one fairly steep but short hill to climb and a bit of a scramble at the end to get back into Jubilee Stone reserve, if you follow our route, but this can be avoided by continuing along the by-way to the road, and then turning right to find where you parked (if on Backwell Hill Road).
We really enjoyed it and will be back to the area again soon, there are loads of paths to choose from. Our route was around 4 miles and took us about an hour and a half.