Pursuant to RCW 36.75.300, there is added to Part 5 of the MUTCD, the following regulation pertaining to signing of county roads:

The legislative authority of each county may by resolution classify and designate portions of county roads as primitive roads where the designated road portion:

(1) Is not classified as part of the county primary road system, as provided for in RCW 36.86.070;

(2) Has a gravel or earth driving surface; and

(3) Has an average annual daily traffic of 100 or fewer vehicles.

Any road designated as a primitive road shall be marked with a PRIMITIVE ROAD sign at all places where the primitive road portion begins or connects with a highway other than a primitive road.

A sign with the caption CAUTION - NO WARNING SIGNS may be installed on the same post with the PRIMITIVE ROAD sign, and may be individually erected at intermediate points along the road section if conditions warrant. In addition, a sign with the caption NEXT . . . . MILES may be installed on the same post below the CAUTION - NO WARNING SIGNS sign.