How Did Route Shields get their shape?

[Pete from Boston]

It says "evacuation". Evacuation routes are probably triangles.

Triangle = Civil Defense, a term pretty much forgotten these days, but whose logo is at the top of the sign.

http://en.wikipedia.org/wiki/Civil_defense

Evacuation signs have been round and blue as long as I have been alive, though they once had the CD triangle tucked in there somewhere. 

[D-Dey65]

Hawaii is a raindrop.

I thought it was a macadamia nut.

[Brandon]

Hawaii is a raindrop.

I thought it was a macadamia nut.

It's the Diamond Head on Oahu.

[Kacie Jane]

I have no knowledge of Washington having a state secondary route system.  got any more info?

Wikipedia has some information on them–apparently the secondaries were letter-suffixed routes branching from the primary routes, similar to OK. The current system arose from a renumbering in 1964. http://en.wikipedia.org/wiki/Primary_State_Highways_%28Washington%29

Not to be confused with the actual branches of the primary routes, which had a two letter suffix, but were (I think) signed with just the number, and part of the primary system.

Generally, a "new" 3-digit route was probably a pre-1964 branch or secondary, while a "new" 1- or 2-digit route was probably a pre-1964 primary, though plenty of exceptions exist both ways, and there's no longer any legal distinction between primary and secondary.

[NE2]

I have no knowledge of Washington having a state secondary route system.  got any more info?

Wikipedia has some information on them–apparently the secondaries were letter-suffixed routes branching from the primary routes, similar to OK.

This is a secondary:

I'm probably wrong about the triangle. But Wisconsin did use a state outline

[Kacie Jane]

Is that background dark green as opposed to black?  Or are my eyes playing tricks on me?

[DaBigE]

I have no knowledge of Washington having a state secondary route system.  got any more info?

Wikipedia has some information on them—apparently the secondaries were letter-suffixed routes branching from the primary routes, similar to OK.

This is a secondary:

I'm probably wrong about the triangle. But Washington Wisconsin did use a state outline

Fixed it for you.

The only outlines Wisconsin ever used are for marking Heritage Trails and Rustic Roads, never officially for state trunk highways.

[NE2]

what

[edit]Washington never used a state outline. But Chris Bessert can eat poo.

[Brandon]

I'm probably wrong about the triangle. But Washington Wisconsin did use a state outline

Fixed it for you.

The only outlines Wisconsin ever used are for marking Heritage Trails and Rustic Roads, never officially for state trunk highways.

Wisconsin started out with the downward pointing triangle as seen on DaBigE's avatar.  It later, by the 1940s evolved into a more modern shape that we seen today.  Why they used the downward pointing triangle?  I have no idea.

[Alps]

Is that background dark green as opposed to black?  Or are my eyes playing tricks on me?

These signs look like they were colorized after the fact. I have trouble believing Nebraska would paint each shield blue and green like that.

[agentsteel53]

I had no idea that the lettered routes were intended to be secondary.  if so, there were only a very small handful of primary routes.  numbered 1-20 or so.  even fewer than the amount of one- or two-digit routes present today.  nowadays, a lot of Washington's three-digit routes can be considered secondary, and the numbering system follows the old number-letter one, except with a numerical final digit.

as for triangle shields marking suffixed routes - I have never seen such a thing; and I bet NE2 indeed misremembered an evacuation route shield.  all the old routes, primary and secondary, were Washington heads as far as I've ever seen.

[national highway 1]

Hawaii is a raindrop.

I thought it was a macadamia nut.

It's the Diamond Head on Oahu.

I'm pretty sure the shield represents the shape of Hawaii, the Big Island.