Reply #187: and what if you don't have the opportunity to see it up ahead?

[kwassa]

I have had a fog bank surround me unexpectedly, by the way, by driving down into a low area, a hollow, so to speak, where the fog could not be seen until seconds before it was entered. It was impossible to achieve a safe speed as quickly as the fog was encountered.

If you can see ahead only a few feet, you should reduce speed to maybe 1-2 MPH. I've had to do that in pea soup fog many, many times. I've been in desert sandstorms where visibility dropped to literally zero in a very short time, but not without warning. When that kind of thing happens, you should already be stopped when visibility hits zero.

So, your belief is that they can't happen without warning?

This seems to be the key to this whole discussion. You don't think this is possible. Correct?