Current Idaho Highway Markers			Current County Highway Markers
Guide signs (BGS)*	Trailblazer	Scenic/ recreational

Idaho has used an outline of the state on it's shield since they first started marking state highways. This is the current shield. Note that ITD uses a previous version of the shield for use on the highway guide signs *(also known by roadgeeks as BGS or "Big Green Signs"). A third route marker is reserved for scenic or recreational routes and uses the MUTCD brown color to match

Current US Highway Markers
Guide signs (BGS)*	Trailblazer	Scenic/ recreational

Idaho currently uses the standard square US shield used in most other states. on highway \ guide signs (BGS) a cut out version of the shield is used that omits the black square. There are some older guide signs that have used the black square version. As with the state marker, a third US route marker is reserved for scenic or recreational routes and uses the MUTCD brown color to match.

Current Interstate Highway Markers
Two Digit Interstate Routes	Three Digit Interstates	Business Loops

Idaho's interstate markers conform to those used in the rest of the United States. With one exception Idaho currently uses the standard 2 digit shield to mark it's only 3-digit interstate 184 along most of it's route. They also utilize the 3-digit shield for this purpose on a few signs, but the route is mostly marked with the 2-digit shield. As in other states, the state name is slowly being phased out of use on the shield.

Historical Highway Markers
from the 1940's	from the late 1940's thru 1960's	US shield from the 1930's	US shield from the 1940's	US shield from approx 1955

 

Historical Interstate Markers
from the former I-15W (now I-86)	from the former I-80N (now I-84)	from the former I-180N (now I-184)	Featuring the state name

Above are shield's used on idaho highways and interstates in the past. the exact dates that highway markers changed to the newer versions is not certain at this time.

Conceptual Idaho Markers
New highway marker	New Scenic/ Recreational marker

What if Idaho's markers were redesigned. What would they look like. I put together a small redesign of the gem state highway marker. and I really like it. The above shields were created in 2006, and are a concept modeled somewhat after Idaho's license plate. these are cut-out shields. the word "scenic" or "recreation" could be used interchangeably.