Running on the Portishead cycle path

Legs are little weary after the longest run we've achieved for a while, 4.25 miles along the Pill to Portishead cycle path this afternoon in the bright cold sunshine.
It's a curious stretch of path which takes you under the M5 bridge, along the side of Portbury Docks, with Avonmouth chugging away in the distance.
In large parts it runs alongside a disused railway line which I assume will be resurrected if the Portishead to Bristol line gets reinstated.
The overwhelming impression is of a hidden and forgotten industrial wasteland as the rail line is overgrown, tunnels are covered in graffiti, the odd burnt out motor scooter lies wrecked by the path and every now and then rusted gates bar the way to large fenced off open spaces, surrounded by flood lights, which I can only assume are secret UFO landing strips. Maybe.
We only managed to get a couple of miles along the route before coming back home, but the biggest challenge wasn't the prospect of spray paint wielding youths or fumes spewing off six lanes of motorway, no, it was more like the pair of walkers ahead of us.
At this point in my training the speed at which I can run is really on slightly quicker than walking pace.
Reason being of course I'm trying to build stamina rather than speed and am quite happy running for an hour at the same speed as I might walk it, just to keep running.
However, it is a bit of a problem when on the slow trot a couple of people out on an afternoon stroll hove into view. They were almost certainly taking their time as well which made it all the more embarrassing as I had to dig deep to find the acceleration to get past them.
At one point I was shoulder to shoulder and could have had a fairly in-depth conversation about the weather and what kind of Christmas they had as my little legs pumped away to move, with glacial progress, ahead of them. Reminded me of one or two Bristol Half Marathons where the power walkers would whistle past and off into the crowd never to be seen again.
Once we finally managed to get round them we paused to catch breath, and realised that if we didn't get running again they'd overtake and we'd have to go through the whole charade again.
We managed to kick on back Ham Green and left a host of dog walkers and afternoon strollers flailing in our wake as the sheer force of our pace scattered them across the path. Sort of.
But blimey was it ever cold, took a nice hot bath to thaw out when we got home and a bowl full of stir fried veggies and rise. Yum. At this rate, should easily hit five miles by the end of January.