DVLA Over 70 Eye Tests

[Terry]

... you were only safe because you didn't hit anyone, changing fog densities/speed ? 

Lawrence, it was only safe because there was nobody else to hit plus the fog density was very uniform. It was broad daylight - insofar as you can call it daylight when surrounded by fog - and I could see enough of the carriageway and central barrier, etc. to have had immediate warning of any deterioration in visibility and take action if it did happen - but it didn't.

On the other hand I've driven on the A12 in the early hours on the single carriageway section through Norfolk and Suffolk and suddenly gone blind driving through a short patch of mist in a dip in the road. Fortunately, the first time I encountered it I was sufficiently aware of it while it was still possible to see through it and ascertain that there was nothing hidden inside it and that the road was dead straight. Even so it was a bit nerve racking when I went blind for a brief instant.