"Keep min 2 dots apart" signs?

[noelbotevera]

Despite the same concept being used in other places, and using different objects (chevrons, botts dots, etc.), I'd say that the pavement dots are pretty much a PA exclusive. Then again, PA has tons of exclusive signage (like the "truck grade map" signs).

[Duke87]

Those yellow signs are in several places across PA...but the white dots I've only seen in two other places in PA:  PA 147 between where the freeway ends and Northumberland, and I THINK on I-80 in the East Stroudsburg area.  If they're not on I-80 now, I feel like they were there maybe 10 years ago?

I've never seen the dots in any of my travels outside of PA.

I distinctly remember the dots being on I-80 in that area on a trip to Cleveland in the summer of 2004. But I want to say they were gone by the subsequent time I was on that stretch of road (summer 2010) and they most certainly are not still there today.

[Roadgeek Adam]

Those yellow signs are in several places across PA...but the white dots I've only seen in two other places in PA:  PA 147 between where the freeway ends and Northumberland, and I THINK on I-80 in the East Stroudsburg area.  If they're not on I-80 now, I feel like they were there maybe 10 years ago?

I've never seen the dots in any of my travels outside of PA.

I distinctly remember the dots being on I-80 in that area on a trip to Cleveland in the summer of 2004. But I want to say they were gone by the subsequent time I was on that stretch of road (summer 2010) and they most certainly are not still there today.

https://goo.gl/maps/cgsbfp9xEGF2

They are noticeable in the 2009 view but gone in 2011.

[hbelkins]

I've seen them on PA 322 in the State College area and on I-80. I guess the combination of pavement markings and regulatory signs can give police cause to pull over drivers who follow too closely.

I need not explain what's wrong with this sentence.

Knowing PennDOT, there's probably a PA 322 sign somewhere. 

[hbelkins]

Looked through my photos. Here are a couple from I-80 eastbound.





And here are three from US 322 east of State College.

[hbelkins]

Looked through my photos. Here are a couple from I-80 eastbound.





And here are three from US 322 east of State College.

[froggie]

Regarding the OP, MnDOT had something similar posted/painted on MN 55 in Wright County.  I'm not sure if it's still there.

[english si]

Edited to add a picture I found, though I don't know which motorway this is:

Looks like it is the M4 section (J16-J17 IIRC) you describe. Though it could be the M1 J16-J17 (I believe that has those chevrons). It isn't the M62 over the Pennines or the M6 north of Preston. Interestingly, the places where it is deployed are always rural with big spaces between exits, but lots of traffic.

The French have it a lot (even though their edge lines provide a similar function), and the UK copied it from them.

[Rothman]

I've seen these signs; I hate them.

[froggie]

I'm curious as to why...

[Rothman]

I just don't think they do much good.  It's also yet another thing the driver has to worry about.  Those blasted dots and worrying about somehow keeping two between you and the car ahead of you is distracting.  Might concentrate on the dots more than the brake lights of the car you're trying to keep the dots behind of. 

Besides, as soon as the dots go away, traffic resumes its old habits anyhow.  Just seems like a lot of paint and signage for little benefit.

[Brandon]

The plowable version are simply called 'plowable reflectors'.

Or "embedded reflectors".  They typically have a steel frame around the reflector.

[qguy]

Just seems like a lot of paint and signage for little benefit.

I always thought the same thing. When I worked for PennDOT I'd pass them from time to time as I traveled around the state. Every time I encountered them, I'd silently roll my eyes.

[jakeroot]

Like almost every traffic law, there seems to be places that it works better than others. On the last page, Kniwt posted about WSDOT using the dots along I-5, north of Olympia. The dots were so effective, that even during rush hour, people kept a 160 foot gap (which ended up causing huge traffic jams). Apparently, Washington State drivers will do anything a sign tells them to.

I'm not certain I like their use along two-lane highways, however. If someone is travelling below the speed limit, and you intend to pass, you shouldn't start overtaking from that far back. Hopefully people have the intelligence to simply ignore the dots for that period of time.

[jeffandnicole]

At least in PA, the dots are used in rural areas and area not prone to congestion.

It's like anything else...it's a good reminder, but in the long run probably not terribly effective.  Such as news stories on a yearly basis gives us advice of how to drive in the snow.  Most people aren't going to remember it, and besides, they know how to drive.  Everyone else is the idiot that can't drive.

[cl94]

Then again, PA has tons of exclusive signage (like the "truck grade map" signs).

Not exclusive. NYSDOT regions 2 and 4 use them in several locations.

As far as "Bott's Dots", they technically refer only to nonreflective raised pavement markers that are roundish. Stimsonite reflective markers (whether recessed or on the surface) and cat's eyes are not the same thing.

[sbeaver44]

I've seen them on PA 322 in the State College area and on I-80. I guess the combination of pavement markings and regulatory signs can give police cause to pull over drivers who follow too closely.

I need not explain what's wrong with this sentence.

Knowing PennDOT, there's probably a PA 322 sign somewhere. 

There is a PA 322 sign near the Lebanon/Lancaster county border eastbound a few miles after the PA 72 exit.

Also, I remember a set of these dots between Exits 37 and 44 on North I-81, somewhere right around the 40 MM.

[74/171FAN]

Also, I remember a set of these dots between Exits 37 and 44 on North I-81, somewhere right around the 40 MM.

I have driven that portion of I-81 a lot over the past year and never saw them.

[noelbotevera]

I've seen them on PA 322 in the State College area and on I-80. I guess the combination of pavement markings and regulatory signs can give police cause to pull over drivers who follow too closely.

I need not explain what's wrong with this sentence.

Knowing PennDOT, there's probably a PA 322 sign somewhere. 

There is a PA 322 sign near the Lebanon/Lancaster county border eastbound a few miles after the PA 72 exit.

Also, I remember a set of these dots between Exits 37 and 44 on North I-81, somewhere right around the 40 MM.

I have driven that portion of I-81 a lot over the past year and never saw them.

Gonna guess he meant exit 67 to 72, around the 70 MM, where US 322 ends its multiplex.

[sbeaver44]

I've seen them on PA 322 in the State College area and on I-80. I guess the combination of pavement markings and regulatory signs can give police cause to pull over drivers who follow too closely.

I need not explain what's wrong with this sentence.

Knowing PennDOT, there's probably a PA 322 sign somewhere. 

There is a PA 322 sign near the Lebanon/Lancaster county border eastbound a few miles after the PA 72 exit.

Also, I remember a set of these dots between Exits 37 and 44 on North I-81, somewhere right around the 40 MM.

I have driven that portion of I-81 a lot over the past year and never saw them.

Gonna guess he meant exit 67 to 72, around the 70 MM, where US 322 ends its multiplex.

No, I'm talking about the Cornwall Bypass, north of the Turnpike Exit 266 where US 322 meets PA 72.

[sbeaver44]

Also, I remember a set of these dots between Exits 37 and 44 on North I-81, somewhere right around the 40 MM.

I have driven that portion of I-81 a lot over the past year and never saw them.

I used to commute to Shippensburg, but this was several years ago.  They were in bad shape then, and probably have been paved over now.

[noelbotevera]

Also, I remember a set of these dots between Exits 37 and 44 on North I-81, somewhere right around the 40 MM.

I have driven that portion of I-81 a lot over the past year and never saw them.

I used to commute to Shippensburg, but this was several years ago.  They were in bad shape then, and probably have been paved over now.

Yup, they do not exist.

With the PA 322 signs, my brain failed and thought you were talking about the I-81/US 322 multiplex...wait a minute, there is a PA 322 sign somewhere around there!

[MASTERNC]

I thought Ontario had something like this on rural roads, except they used chevrons pointing in the direction of travel

[1995hoo]

I thought Ontario had something like this on rural roads, except they used chevrons pointing in the direction of travel

Further up the thread:

I seem to recall some conceptually-similar signs on the eastbound M4 somewhere east of Bristol (England) with a scheme that used chevrons instead of dots.

Ontario used to have them on the 401 at one point, though they are no longer in use.

[webfil]

Austria also uses dots on its motorways, but they are used to adopt a recommended speed in areas prone to fog when fog occurs.



In those areas, a succession of signs can be observed
1. In case of fog, pay attention to dots
2. Two dots perceptible = recommended speed of 60 km/h
3. One dot perceptible = recommended speed of 40 km/h

Dots are 33 metres one from another.

Same principle, different application