On US 322 between PA 45 and PA 144, there are three sections of road where dots appear. Signs that say "Keep min 2 dots apart" are posted on the three sections.
Here's (https://www.google.com/maps/@40.7874593,-77.7142019,3a,34.2y,82.5h,92.07t/data=!3m6!1e1!3m4!1stoP6v7nW87eH0sAuQdCKCQ!2e0!7i13312!8i6656) an example of one of the signs.
Have these been used anywhere else, or is it a PA exclusive? Also, do these dots have a name?
I think this must have been a high accident area of US 322 (we saw skid marks along one of the dotted sections), and PennDOT must have experimented with these a couple years ago (the paint is fairly new, and the signs are Clearview - the GSV shows 2012).
The strange thing is that the dots have no warning of them ending. Basically they just suddenly disappear, and the next sign that tries to warn you about following distance is this (https://www.google.com/maps/@40.7918724,-77.697206,3a,75y,100.14h,89.12t/data=!3m6!1e1!3m4!1s8O01PKgTKzeIQpwcp4dmrw!2e0!7i13312!8i6656), this (https://www.google.com/maps/@40.7953381,-77.6778648,3a,15y,91.14h,87.2t/data=!3m6!1e1!3m4!1sOIPa29ker14FAE5k9LPOCA!2e0!7i13312!8i6656), and this, at the next dotted section (https://www.google.com/maps/@40.7961561,-77.6737306,3a,36.9y,93.78h,87.81t/data=!3m6!1e1!3m4!1s772zhWsNVMN0sCwfhenAbg!2e0!7i13312!8i6656).
Those dots probably represent 1 second of travel time at the posted speed limit for that road, so 2 dots would equal the 2 second gap we are supposed to leave between us and the vehicle in front of us.
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.
Quote from: jemacedo9 on January 09, 2016, 05:26:56 PM
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've never seen anything like that myself, I am just guessing at this point (though it would make sense). I haven't been to PA myself since 1987 if memory serves.
There's no ending sign because you're never supposed to tailgate. In theory, it has helped you determine how far apart you should always be behind the car in front of you. There's no end point in when you're allowed to tailgate again.
The problem comes when people do tailgate. You have conga lines of four or more cars abutting each other, and they're less than half a dot away. That's equivalent to about half a second or so away (the speed limit for this stretch here is 55 mph).
Quote from: noelbotevera on January 09, 2016, 06:26:42 PM
The problem comes when people do tailgate. You have conga lines of four or more cars abutting each other, and they're less than half a dot away. That's equivalent to about half a second or so away (the speed limit for this stretch here is 55 mph).
I like to remain fairly distant from the vehicle ahead of me. Anyone who tailgates me generally finds that if they don't back off I'll drive slower just to piss them off.
They're not there anymore, but at one point (I'm guessing about 10 years ago, but I'm pulling that number out of my you know where), I-5 north of Olympia had them.
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.
Edited to add a picture I found, though I don't know which motorway this is:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.roberthempsall.co.uk%2Fblogimages%2Fkeep-apart-2-chevrons-road-sign.jpg&hash=edf21c5f0e0cd0d94bf91b23b7f4beece24b439a)
Quote from: slorydn1 on January 09, 2016, 05:23:11 PM
Those dots probably represent 1 second of travel time at the posted speed limit for that road, so 2 dots would equal the 2 second gap we are supposed to leave between us and the vehicle in front of us.
Information on this is on page 5-91 in PENNDOT Publication 638 (http://www.dot.state.pa.us/public/pubsforms/Publications/PUB%20638.pdf)(District Highway Safety Guidance Manual).
The major information is placed below, I have not seen or heard of anything like this to this point but it seems to be a possible way of implementing low-cost safety improvements on two or three-lane roads.
QuoteMarkings are spaced such that safe distance is kept between vehicles when a minimum of two markings separates them. Safe distance is defined based on a 2 second following rule.
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.
Quote from: hbelkins on January 09, 2016, 09:41:58 PM
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.
As for the topic at hand, the ones on I-80 I've known for a long time. I loved them as a kid, because they were so unusual to me at least.
Quote from: 1995hoo on January 09, 2016, 07:51:28 PM
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.
This should probably go in traffic control.
Quote from: 1995hoo on January 09, 2016, 07:51:28 PM
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.
Can't remember which motorway (hell, it could have been an A-road), but the UK's implementation was my first experience with "keep apart" signs. I'm glad to see them making their way over here. However, British motorists are quite a lot more disciplined than we are, so I'm uncertain as to how effective these dots will end up being, this side of the pond.
There used to be a set on former US 220 around Port Matilda, PA but I think they were gone last time I was through. After the traffic moved to I-99, I suspect PennDOT decided they weren't worth maintaining anymore.
Quote from: jakeroot on January 10, 2016, 04:17:56 AM
This should probably go in traffic control.
Quote from: 1995hoo on January 09, 2016, 07:51:28 PM
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.
Can't remember which motorway (hell, it could have been an A-road), but the UK's implementation was my first experience with "keep apart" signs. I'm glad to see them making their way over here. However, British motorists are quite a lot more disciplined than we are, so I'm uncertain as to how effective these dots will end up being, this side of the pond.
Funny thing is, I seem to remember that when I took driver's ed they advocated a two-second following distance under 40 mph and a four-second distance over 40 mph. I've tried counting off what a four-second distance would be and it's HUGE. It'd be pretty much impossible to maintain that distance on most urban or suburban highways I travel because people would cut into the gap. Even a two-second distance is probably farther than most people perceive when they think about what distance is safe, although that's no excuse for following too closely. (Out on rural non-Interstates it doesn't much matter either way due to lack of traffic.)
Semi-related to this topic: When I read car reviews that mention adaptive cruise control where the car adjusts the following distance to keep a safe space, I've often wondered if such systems can be essentially counterproductive on highways with relatively high traffic volumes and aggressive drivers because even with a two-second distance, somebody's going to cut into that gap, and I assume that means the adaptive cruise will back off the speed to re-create a two-second gap, which in turn is an invitation for another driver to cut in, etc....eventually the car backs it off so far that you're not getting anywhere. Or am I missing something? (Aside from the sensible driver not using the system in that kind of traffic, of course.)
Quote from: cu2010 on January 10, 2016, 04:10:22 AM
Quote from: 1995hoo on January 09, 2016, 07:51:28 PM
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.
I don`t have a picture of the signs, but here are some of the remaindered chevrons on the 401 through Whitby.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fasphaltplanet.ca%2FON%2Fhwy_401_images%2F401_cl_409_east_May05.jpg&hash=86f3f5ecd9699334d0a9ceb6e13cc0ae79838a98)
http://asphaltplanet.ca/ON/hwy_401_images/401_cl_409_east_May05_lg.jpg
http://www.asphaltplanet.ca/ON/hwy_401_images/Hwy401_p11_images.htm
The 400 also had some through King Township in York Region:
http://www.thekingshighway.ca/PHOTOS-4/hwy400-311_xlg.jpg
http://www.thekingshighway.ca/PHOTOS-4/hwy400-313_xlg.jpg
http://www.thekingshighway.ca/PHOTOS/Hwy400photos5.htm
It was tried in 2006 in Washington state and very quickly abandoned.
http://thenewspaper.com/rlc/news.asp?ID=1289
QuoteDuring heavy Saturday traffic, however, motorists maintained the 160-foot distance as required by the posted signs, even though such distances were unnecessary at the crawling pace. This further reduced the freeway's capacity causing a chain-reaction slow-down.
"The idea was not to impede traffic, but to increase safety," state Traffic Engineer Ted Trepanier said in a statement provided to The Olympian newspaper. "We apologize for delays drivers faced as a result of this program."
Quote from: noelbotevera on January 09, 2016, 06:26:42 PM
The problem comes when people do tailgate. You have conga lines of four or more cars abutting each other, and they're less than half a dot away. That's equivalent to about half a second or so away (the speed limit for this stretch here is 55 mph).
It's actually about a second at that point.
The way it works is there's two dots. Trying to explain it here, it works like this:
Car Dot Dot Car
As you see, there's a wide space between those two dots. If a car was 1/2 second away, it'll look like this:
Car Dot Car Dot Car
But if a car was one second away, it'll look more like this:
Car Dot Car Dot Car
Another thing to do is count 'One Mississippi Two Mississippi' wth a fixed object or marking, such as a sign or line in the road. You should be able to say One Mississippi with ease. Obviously, it's better to say One Mississippi Two Mississippi, but honestly in the real world in heavy traffic that rarely happens.
Quote from: hbelkins on January 09, 2016, 09:41:58 PM
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.
What's the specific law on tailgating or following too closely? While your safety publications generally will say 2 or 3 seconds, many states don't actually have that written into law.
Quote from: Zeffy on January 09, 2016, 07:36:00 PM
Quote from: noelbotevera on January 09, 2016, 06:26:42 PM
The problem comes when people do tailgate. You have conga lines of four or more cars abutting each other, and they're less than half a dot away. That's equivalent to about half a second or so away (the speed limit for this stretch here is 55 mph).
I like to remain fairly distant from the vehicle ahead of me. Anyone who tailgates me generally finds that if they don't back off I'll drive slower just to piss them off.
That's a form of aggressive driving. No, not them. You. And you're not just pissing that next person off, but everyone behind them. In the end, it aggravates everyone, and it doesn't solve anything.
Whenever I see the dots, I intentionally get closer to the car in front of me. Just like when I see "Buckle up! Next million miles!" I immediately unbuckle my safety belt. Screw you nanny signs.
Quote from: noelbotevera on January 09, 2016, 05:16:49 PM
Also, do these dots have a name?
I don't know about an "official" name, but I recall when these showed up in PA, reading the name "Bott's Dots" (I think 2 "t"'s in Bott)
Quote from: Mr_Northside on January 10, 2016, 02:49:43 PM
Quote from: noelbotevera on January 09, 2016, 05:16:49 PM
Also, do these dots have a name?
I don't know about an "official" name, but I recall when these showed up in PA, reading the name "Bott's Dots" (I think 2 "t"'s in Bott)
Bott's Dots are the physical dots separating lanes, seen mainly in non-snowy climates (although versions exist that are protected from snowplows)...
(https://upload.wikimedia.org/wikipedia/commons/3/33/Farmhillblvd.jpg)
Quote from: Alps on January 10, 2016, 02:21:47 PM
Whenever I see the dots, I intentionally get closer to the car in front of me. Just like when I see "Buckle up! Next million miles!" I immediately unbuckle my safety belt. Screw you nanny signs.
(https://v.cdn.vine.co/r/avatars/BE361F4E501154222190200492032_pic-r-1418162221640d3c211b0fe.jpg.jpg?versionId=b1ecVrwizhw2cxapJOfvr0sFne9Xc2HZ)
Quote from: jakeroot on January 10, 2016, 02:53:50 PM
Quote from: Mr_Northside on January 10, 2016, 02:49:43 PM
Quote from: noelbotevera on January 09, 2016, 05:16:49 PM
Also, do these dots have a name?
I don't know about an "official" name, but I recall when these showed up in PA, reading the name "Bott's Dots" (I think 2 "t"'s in Bott)
Bott's Dots are the physical dots separating lanes, seen mainly in non-snowy climates (although versions exist that are protected from snowplows)...
(https://upload.wikimedia.org/wikipedia/commons/3/33/Farmhillblvd.jpg)
Quote from: Alps on January 10, 2016, 02:21:47 PM
Whenever I see the dots, I intentionally get closer to the car in front of me. Just like when I see "Buckle up! Next million miles!" I immediately unbuckle my safety belt. Screw you nanny signs.
(https://v.cdn.vine.co/r/avatars/BE361F4E501154222190200492032_pic-r-1418162221640d3c211b0fe.jpg.jpg?versionId=b1ecVrwizhw2cxapJOfvr0sFne9Xc2HZ)
The plowable version are simply called 'plowable reflectors'.
Stretches of Route 41 between US 1 & 30 in Chester & Lancaster Counties have these as well.
Quote from: PHLBOS on January 10, 2016, 05:32:06 PM
Stretches of Route 41 between US 1 & 30 in Chester & Lancaster Counties have these as well.
Including just west of PA 796 in Chesco, which is burned in my brain having negotiated that stretch numerous times on my way to my stepbrother's or to Reading.
ixnay
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).
Quote from: jemacedo9 on January 09, 2016, 05:26:56 PM
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.
Quote from: Duke87 on January 10, 2016, 09:08:27 PM
Quote from: jemacedo9 on January 09, 2016, 05:26:56 PM
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.
Quote from: Roadgeek Adam on January 09, 2016, 10:10:33 PM
Quote from: hbelkins on January 09, 2016, 09:41:58 PM
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. :-D
Looked through my photos. Here are a couple from I-80 eastbound.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fmillenniumhwy.net%2F2009_Milford_PA_Day_2%2FImages%2F481.jpg&hash=615199f88e9a39435a76597c7cf67062d16de5a3)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fmillenniumhwy.net%2F2009_Milford_PA_Day_2%2FImages%2F482.jpg&hash=14afac1deb4a0d002653a282ce9026f14229a2bb)
And here are three from US 322 east of State College.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fmillenniumhwy.net%2F2009_State_College_Day_3%2FImages%2F24.jpg&hash=b82ab4a7172991a63167d2c8e0ae9b020cb0a0c7)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fmillenniumhwy.net%2F2009_State_College_Day_3%2FImages%2F25.jpg&hash=52e26bf8a10b5b25060963e143b410c89218cd25)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fmillenniumhwy.net%2F2009_State_College_Day_3%2FImages%2F26.jpg&hash=960bc1cfda80b761982c3fc7ce7cd79fc49091be)
Looked through my photos. Here are a couple from I-80 eastbound.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fmillenniumhwy.net%2F2009_Milford_PA_Day_2%2FImages%2F481.jpg&hash=615199f88e9a39435a76597c7cf67062d16de5a3)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fmillenniumhwy.net%2F2009_Milford_PA_Day_2%2FImages%2F482.jpg&hash=14afac1deb4a0d002653a282ce9026f14229a2bb)
And here are three from US 322 east of State College.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fmillenniumhwy.net%2F2009_State_College_Day_3%2FImages%2F24.jpg&hash=b82ab4a7172991a63167d2c8e0ae9b020cb0a0c7)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fmillenniumhwy.net%2F2009_State_College_Day_3%2FImages%2F25.jpg&hash=52e26bf8a10b5b25060963e143b410c89218cd25)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fmillenniumhwy.net%2F2009_State_College_Day_3%2FImages%2F26.jpg&hash=960bc1cfda80b761982c3fc7ce7cd79fc49091be)
Regarding the OP, MnDOT had something similar posted/painted on MN 55 in Wright County. I'm not sure if it's still there.
Quote from: 1995hoo on January 09, 2016, 07:51:28 PMEdited 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.
I've seen these signs; I hate them.
I'm curious as to why...
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.
Quote from: jeffandnicole on January 10, 2016, 04:53:30 PM
The plowable version are simply called 'plowable reflectors'.
Or "embedded reflectors". They typically have a steel frame around the reflector.
Quote from: Rothman on January 11, 2016, 11:46:34 AM
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.
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.
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.
Quote from: noelbotevera on January 10, 2016, 07:00:32 PM
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.
Quote from: hbelkins on January 10, 2016, 10:01:18 PM
Quote from: Roadgeek Adam on January 09, 2016, 10:10:33 PM
Quote from: hbelkins on January 09, 2016, 09:41:58 PM
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. :-D
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.
Quote from: sbeaver44 on January 15, 2016, 04:19:19 PM
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.
Quote from: 74/171FAN on January 15, 2016, 05:05:20 PM
Quote from: sbeaver44 on January 15, 2016, 04:19:19 PM
Quote from: hbelkins on January 10, 2016, 10:01:18 PM
Quote from: Roadgeek Adam on January 09, 2016, 10:10:33 PM
Quote from: hbelkins on January 09, 2016, 09:41:58 PM
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. :-D
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.
Quote from: noelbotevera on January 15, 2016, 05:27:50 PM
Quote from: 74/171FAN on January 15, 2016, 05:05:20 PM
Quote from: sbeaver44 on January 15, 2016, 04:19:19 PM
Quote from: hbelkins on January 10, 2016, 10:01:18 PM
Quote from: Roadgeek Adam on January 09, 2016, 10:10:33 PM
Quote from: hbelkins on January 09, 2016, 09:41:58 PM
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. :-D
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.
Quote from: 74/171FAN on January 15, 2016, 05:05:20 PM
Quote from: sbeaver44 on January 15, 2016, 04:19:19 PM
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.
Quote from: sbeaver44 on January 15, 2016, 05:45:09 PM
Quote from: 74/171FAN on January 15, 2016, 05:05:20 PM
Quote from: sbeaver44 on January 15, 2016, 04:19:19 PM
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!
I thought Ontario had something like this on rural roads, except they used chevrons pointing in the direction of travel
Quote from: MASTERNC on January 15, 2016, 07:16:33 PM
I thought Ontario had something like this on rural roads, except they used chevrons pointing in the direction of travel
Further up the thread:
Quote from: cu2010 on January 10, 2016, 04:10:22 AM
Quote from: 1995hoo on January 09, 2016, 07:51:28 PM
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.
Austria also uses dots on its motorways, but they are used to adopt a recommended speed in areas prone to fog when fog occurs.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fkiwithek.kidsweb.at%2Fimages%2FHinweisschilder_Nebel.jpg&hash=a10653c2e79065aa67474786cd1860e0cefc0d54)
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
Quote from: webfil on January 20, 2016, 08:36:35 PM
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
That strikes me as a much more practical use of these things, since they actually provide the driver with information that's less obvious and routine.
The problem with PennDOT's use of them is that it's just nanny signage, of the sort PennDOT loves to employ - "Buckle up next million miles", etc. These signs are unnecessary clutter because they are instructing drivers to do something that they should be doing all the time without a sign telling them. The point of signs is to provide drivers with situation specific information, like the name of the street at this intersection, or the fact that there is a sharp curve ahead.
This was the actual sign on the 401 in the Whitby section......which looks nearly identical to the one across the pond:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fstatic.flickr.com%2F24%2F62025020_6d0173fce5_o.jpg&hash=73473779b14b041a625bb023305f9713b48ca699)
I'm not sure when the sign disappeared as I grew up on the other end of the GTA, but I do last recall seeing it around November 2000ish, so it's quite some time ago....the actual chevrons remained in place until rather recently as can be seen from AsphaltPlanet's photos.
Quote from: cl94 on January 12, 2016, 09:33:50 PM
Quote from: noelbotevera on January 10, 2016, 07:00:32 PM
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.
Interestingly enough, when I took driver's ed (in 1995 in New York State), we were taught to keep 1 second of following distance per 10 MPH, and to do this by counting 1 Mississippi, 2 Mississippi, from the time the car ahead of you passed some fixed object on the side of the road like a sign or a tree. If you passed that sign or tree before you finished counting you were following too closely. So... 2 dots being 2 seconds at the posted speed limit only meshes with official NYS Driver's Ed Training when the speed limit is 20 MPH.
Of course, no one seriously keeps that much following distance.
Quote from: tckma on March 17, 2016, 03:11:19 PM
Quote from: cl94 on January 12, 2016, 09:33:50 PM
Quote from: noelbotevera on January 10, 2016, 07:00:32 PM
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.
Interestingly enough, when I took driver's ed (in 1995 in New York State), we were taught to keep 1 second of following distance per 10 MPH, and to do this by counting 1 Mississippi, 2 Mississippi, from the time the car ahead of you passed some fixed object on the side of the road like a sign or a tree. If you passed that sign or tree before you finished counting you were following too closely. So... 2 dots being 2 seconds at the posted speed limit only meshes with official NYS Driver's Ed Training when the speed limit is 20 MPH.
No it doesn't. Regardless of the speed, 1 Mississippi 2 Mississippi works out to about a car length for every 10 mph. Even if you're travelling 70 mph, 2 Mississippis gives you about 7 car lengths of space.