[boomboomsubban]

Worse, they mention supervised traffic, so presumably at some point people standing outside next to speeding traffic and radiation.

Also, how fast is "safe" when seemingly you'll regularly be encountering crashed cars from people who didn't make it?

[thfuran]

What do you mean crashed cars from people who didn't make it? The sign is basically a "minimum speed 40 mph" sign routinely seen on the interstates but with a bit more teeth. The sides of highways aren't usually lined with crashed cars (except occasionally when winter gets feisty).

[myself248]

If I have permission to do 150, you bet I'm going to do 150. Even though I don't exactly have a ton of experience doing it. A fair number of people are going to misjudge, overcontrol, suffer equipment failures, etc.

[thfuran]

>If I have permission to do 150

Doing ~100 over the speed limit probably isn't considered safe, so I'd guess you don't.

[boomboomsubban]

I understood it as "this level of radiation could kill you in hours, but this is the only way to a fallout shelter." Reading other posts made after mine I appear to be mistaken.

[wincy]

Those signs are all over Georgia and it absolutely wigged out my Toyota’s sensor that scans speed limit signs. For 3 hours the car thought the speed limit was 40mph while I was going 85.

[inejge]

[...] they mention supervised traffic, so presumably at some point people standing outside next to speeding traffic and radiation.

It can be supervised at entry/exit points, which is what I infer from the text. A bit like the highway across East Germany to West Berlin during the Cold War.