NC: I-40 "Accident Investigation Site Ahead" Sign AND Brown numbered signs

[Dustin DeWinn]

I want to devote this thread 2 two types of signage I saw on a trip from NC to TN as I drove through the Smoky Mountains on I-40.

One was "Accident Investigation Site Ahead". These are permanent white diamonds. Do these exist anywhere else?



Believe it or not, this is the only image I could find on the web, but there are a lot of these signs. Some in REALLY treacherous areas.


The second type, I looked for on Google Maps but couldn't find are numbered brown signs with white lettering that are fairly small, but larger than mile markers. They're in very close proximity and go 9 8 7 6 5 4 3 2 1 0 1 2 3 4 5 6 7 8 9

They're not a 10th of a mile apart. I don't know what they are.

Anyone have any idea?

[Big John]

Threat on Accident Investigation sites: https://www.aaroads.com/forum/index.php?topic=14978.0 but the signs are different (white on blue rectangle in WI for instance)

[Eth]

This is the Accident Investigation Site sign I'm more familiar with (in this case, semi-uselessly posted at the end of such a pull-off).

[hbelkins]

The brown numbered signs, I've been told, are placed in fog-prone areas, although I don't know why they're there or what they're for.

[chays]

These articles might shed some light on the little brown signs: https://www.reddit.com/r/whatisthisthing/comments/64dt5q/small_numbered_sequential_brown_signs_on_i40_west/
https://boards.straightdope.com/sdmb/showthread.php?t=747291

HB was correct about the fog assessment.
The thought is that the camera on this pole (https://goo.gl/maps/tr6guZLW6JD2) is used to determine the current state of fog in that area.