Daniel Immerwahr

So the US is advanced in auto manufacturing.

So it adopts a stop sign early and it's just a local stop sign.

So there's a square stop sign and a Detroit cop is like, square is not

scream and stop to me.

So he clips the corners off, making it octagonal.

And he's like, okay, well, that's clear.

It has a more obvious visual identity.

And then so the United States form of stop sign proliferates in the United States.

And then in 1953, so not too far after World War II,

there's an international standard for stop sign, which adapts the US yellow octagonal stop sign as a standard.

And if you're hesitating this moment being like, wait, yellow?

That's because the US stop signs were yellow.

All the countries are like, okay, to the degree that you can, have your stop signs be yellow octagons.

That would make it a lot easier to travel from country to country if we all kind of agreed what a stop sign looked like.

And then the next year, 1954, industrial chemists in the United States develop a

durable, reflective red finish.

And traffic engineers are like, red would be better.

Red would be better.

It would match the traffic lights.

That's a good idea.