I forgot to mention that, last night, at Mitcham Common, I saw an artic running down the slope from a railway bridge onto the small roundabout, almost into the car which was already turning around it. The braking was quite dramatic, and I am glad it worked. However, I was entering the RAB at the next road, and I wasn't sure where the sleepy HGV driver was going. If it was my narrow exit, with a ditch alongside and oncoming traffic, I had no way to escape. Fortunately, he headed down towards Croydon.