because some witnesses saw 'her' hunched over against the wall in a position that suggested it. Not everyone describes it this way - but some have.Why do the witnesses think it is distressed?
Actually quite the opposite i think - the outline of a female shape (imagine a dress to the floor) is less complex than that for a male.The real bother to me is that a fog/gas/dust effect would very rarely look human and on the rare occasions it does it would be unlikely to always look like a girl.
with headlight reflection - it does appear solid in parts.Another thing is that a misty form would not look solid but people contacting the police about a girl suggests a solid figure is what they see.
I totally agree - but i would add that no one is suggesting a single cause - we have been discussing possibilities and trying to just play with ideas for plausibility.Also those conditions happen in most places and surely on more than that one kilometer section of that road. Why are these sightings not widespread. I think it must be a combination of factors that produce this effect in such a narrow area. Looking for one single cause may be fruitless.