Dialled 999. Was on way home from work @ around 3pm, heading South on M1. Just got past the bridge at Dodworth (The tall one NeedleBridge?) and at the next one, or one after, cant be sure ... there was a young woman (20+) head in hands standing (behind the barrier) on the bridge, but just staring at the carriageway. Obviously at motorway speed I only got a quick glimpse of her, but it just looked all wrong. My heart was in my mouth. Even then I was in 2 minds whether I should ring police or not (didn't want to waste police time if she was innocently just looking at the motorway), but it really scared me. Anyway I rang them & they said they were sending someone. Presumably (hopefully) it was a false alarm. Pretty scary though.