Driving down M5 towards Clevedon on the bit where road is on two levels with quite steep rock sides - noticed lots of what looked like small white labels (hard to tell size whilst passing at speed but maybe about 5-6 inches long) stuck to the rocks over a distance of at least a couple of hundred yards (they were not there a couple of weeks ago). Anyone know what they are / for? I've always been curious about odd things - DP says I am weird!