This sounds silly. Driving home just now I slowed down to observe signs that were indeed angled towards me in such a way as to briefly reflect my headlights. But even then, the return was swamped by the Scotchlite beads, which are just as bright if angled away from you! The only way I can imagine getting dazzled by a shiny sign is by the Sun rising or setting somewhere behind me. But that geometry changes day-to-day, so the only logical tilt angle is slightly face down. (OCD extra credit: Affinely distort the content to compensate the angle.) Then we still have Scotchlite dazzle if the Sun is exactly behind us. (Which is dwarfed by the problem of the Sun being exactly in front of us.) --rwg On 2016-06-22 15:27, Tom Rokicki wrote:

Yep! I originally wrote "would anyone like to speculate ... " but decided not to give it away so easily.

On Wed, Jun 22, 2016 at 2:55 PM, Mike Speciner <ms@alum.mit.edu> wrote:

...

So you don't get direct reflection from your headlights?

On 22-Jun-16 17:19, Tom Rokicki wrote:

...

In the US, road signs are mounted slightly *counterclockwise* (when viewed from above).

Without looking it up, does anyone want to guess why this might be?

-tom

On Wed, Jun 22, 2016 at 7:31 AM, Bill Gosper <billgosper@gmail.com> wrote:

I threw an Aerobie down the street, trying to reach a certain road sign.

...

Standing at the Aerobie, I was disappointed to see the face of the sign, across the street. But wait a minute, it's crooked! Eyeballing a perpendicular to the street, I'm a couple feet past the sign, dammit.

Whoa, maybe roadsigns are twisted slightly clockwise on purpose? To exactly face traffic from where they first become visible? --rwg