I was looking at the website for the local JogScotland group and found the following safety recommendation:
" Hi-viz, reflective, light or bright clothing should be worn at all times whether off-road or on-road for the following reasons:
· On-road: other road users will see you from a distance
· Off-road: should you have an accident; you will be more easily located by passersby, mountain rescue teams, and rescue helicopters
· Dog walkers can see you in time to keep their dogs under control
· Horse-riders can prepare their horses to avoid potential panic
· Wild-fowlers, game hunters (yes they are around the area) will see you better
· Mountain bikers will spot you, with luck, before colliding with you"
Personally I have not felt the need to be seen from a distance when running off-road. I like to slip through the country lanes and woods as discretely as possible. I only occasionally encounter dog walkers on my usual routes, and have only met horse riders once and no mountain bikers - yet!
I can understand the second point, and when out hillwalking I carry a neon yellow 'bothy bag' (emergency shelter) so I can be spotted my the Mountain Rescue Team. But on the footpaths where I run, I'm not likely to slip down a gorge or fall into a deep ditch, or otherwise be unseen by passers-by even if I'm wearing dark clothing.