Do You Remember The "Magic" Speed Limit Signs???

[The High Plains Traveler]

I saw these in Utah in the 1960s while traveling with my parents. Seems to me in looking through the 1948 MUTCD, where the modern era of road signage was introduced, that referenced this type of sign as one of two acceptable means of posting night speed limits (the other being the white on black night limit sign paired with a non-reflective daytime limit.

[averill]

This is my rendering of what the day/night speed limit sign looks like using black reflective sheeting.  I have made a few of these myself, both miniature and full size.  I remember them and loved them.  I hope to get a used one someday.

[averill]

I saw these in Utah in the 1960s while traveling with my parents. Seems to me in looking through the 1948 MUTCD, where the modern era of road signage was introduced, that referenced this type of sign as one of two acceptable means of posting night speed limits (the other being the white on black night limit sign paired with a non-reflective daytime limit.

I think this practice was in the MUTCD until almost the 2000 edition.  I have all of them and I know it is in the 78 MUTCD.

[agentsteel53]

I saw a photo once of an Arizona speed limit sign from the early 40s with white text on a black background spelling out "SPEED LIMIT 60" - but with the glass cateyes spelling out "SPEED LIMIT 50" instead. 

[texaskdog]

The wave of the future, electronic speed limit signs that could adjust for road conditions? 

[Kacie Jane]

The wave of the future, electronic speed limit signs that could adjust for road conditions? 

Wave of the present in a lot of metropolitan areas.  The New Jersey Turnpike has had them for decades.

[texaskdog]

Always amazed how a speed limit in rush hour or at night is the same as a wide open highway.   

[1995hoo]

The wave of the future, electronic speed limit signs that could adjust for road conditions? 

We had those on part of the Beltway for about two years beginning in July 2008, but they were removed. People ignored the varied speed limit as much as, maybe more than, they ignore the normal one.

When I picture variable speed limit signs I always think of Rosco P. Coltrane hitting the button to flip over the panel on that sign to change it from 35 to 15 or whatever.

[myosh_tino]

When I picture variable speed limit signs I always think of Rosco P. Coltrane hitting the button to flip over the panel on that sign to change it from 35 to 15 or whatever.

Rosco P. Coltrane from The Dukes of Hazzard for those that aren't familiar with that name.

Loved the TV show... 
Hated the Movie... 

[OracleUsr]

The wave of the future, electronic speed limit signs that could adjust for road conditions? 

We had those on part of the Beltway for about two years beginning in July 2008, but they were removed. People ignored the varied speed limit as much as, maybe more than, they ignore the normal one.

When I picture variable speed limit signs I always think of Rosco P. Coltrane hitting the button to flip over the panel on that sign to change it from 35 to 15 or whatever.

Yeah, and he'd always demonstrate it in Boss Hogg's office and the thing would go haywire, causing immense winds inside the office.

I watched that show every chance I got, even though I think my parents feared it would teach me to disrespect real life police.

[averill]

One of my parents told me about those signs once.  Apparently vandals sometimes bent the signposts to funny angles, somehow making the day.speed limit display at night.

Retroreflective black sounds like an oxymoron, but it's actually charcoal gray, not black.  The vans I drive at work have their numbers in retroreflective charcoal gray; the rest of the van is of course nonreflective white.  At certain headlight distances, this combination is unreadible because the retroreflected dark gray is the same brightness as the diffused white.

I appreciate you telling us how the black reflective sheeting can be reflective.  In this case charcoal Gray could be used on the newer, higher reflective sheeting in the same way by just adjusting the amount of grey to keep the black appearance during the day, but making them more invisible at night.

[bulkyorled]

Does it change with temperature? The picture looked like it was that kind of magic haha There are signs that resemble that here but they're LED signs so not quite the same type of magic...