I've started noticing long stretches of freeway in D7 where "Botts Dots" have clearly been removed. In particular along the Santa Monica Freeway between Lincoln and around La Brea and along the Santa Ana portion of the 101 in Downtown LA between Vignes and the Four Level Interchange. I sent in the question to D7 via twitter and got an interesting response (links below).
Question: https://twitter.com/AndyMax25/status/815655211045765120
Answer: https://twitter.com/CaltransDist7/status/816699846434422786
I was at an ITE conference last year and recall hearing the D7 director mention that they are going to be removing Botts Dots. Her reason was because they were getting too many complaints from vehicle navigation system companies. She stated that the companies were concerned that the vibrations from the Botts Dots were disrupting the navi systems and cause them to not function properly. At the time I though what a silly reason to compromise safety and spend tens of thousands of dollars to remove a more than 60 year investment.
Has anyone heard about this "state-of-the-art thermoplastic lane marking material"? Any policy directive or memo out there?
Quote from: AndyMax25 on January 04, 2017, 02:05:45 PM
I was at an ITE conference last year and recall hearing the D7 director mention that they are going to be removing Botts Dots. Her reason was because they were getting too many complaints from vehicle navigation system companies. She stated that the companies were concerned that the vibrations from the Botts Dots were disrupting the navi systems and cause them to not function properly. At the time I though what a silly reason to compromise safety and spend tens of thousands of dollars to remove a more than 60 year investment.
Wow, that's totally ridiculous. I mean, god forbid someone not be notified of their upcoming exit early enough because of the inconvenient rumbles of a safety warning device. In my view, D7 needs these more than anyone. Hopefully they're at least lumping the removals into existing projects in order to gradually remove them instead of going out just to remove them.
I think a letter to Caltrans is in order...
And maybe they're talking about this? Something that would come loose and wash into the ocean.
https://www.swarco.com/en/Products-Services/Traffic-Materials/Glass-Beads
^ Glass beads have been in roadway paint for a very long time.
And glass is made of sand, so it's pretty benign. Solvents from the paints would be far more damaging to the environment than the glass.
Quote from: AsphaltPlanet on January 04, 2017, 02:38:24 PM
^ Glass beads have been in roadway paint for a very long time.
And glass is made of sand, so it's pretty benign. Solvents from the paints would be far more damaging to the environment than the glass.
Glass is partially made of sand, but it's a lot of other, sometimes toxic materials. I realize that I don't know enough about this particular glass to say what it's actually made of, but it's not as if glass just dissolves in water. I realize micro beads are different since they're plastic, but it's the same thing: they look like food to a lot of marine life. That's why they were banned here.
^ Typically the most toxic component in glass is the silica sand itself. Particles of silica sand are found in that sweet spot that will get lodged in a humans lung if inhaled. It's possible for glass to be treated with lead or other metals, but such treatment is typically used only for special cosmetic glass, structural glass or for glass used in electronics. Silica sand just settles to the bottom of a watercourse typically. It is possible for glass to leach if it has been treated with metals, however, as noted above, metals are only added for special types of glass. In fact, because there is both so little market demand for recycled crushed glass, and because of it's relatively benign properties, there is a growing movement to use glass as cover for landfilling operations.
Yes, it is true that Botts dots are going away. They have been (or will be) removed from Caltrans' standard plans. I understand that maintenance is a major reason why. The reason given by the district 7 director is news to me. I'm friends with our traffic engineering branch chief, who is overseeing this, and I'll confirm it with him.
I think it's important to note that when we talk about Botts' dots, we're talking about round raised pavement markers. We're not talking about the square pavement reflectors. Those are not going away. An earlier poster made reference to marking an offramp. Reflectors are used for those purposes, not Botts' dots.
We will be requiring striping to basically have a minimum amount of reflectivity, much like we require for signing. We do not have any such requirement now. Autonomous vehicle manufacturers have been talking with us about improving the visibility of our stripes.
iPhone
It's been discussed before, but D7, if anything, is excellent at public response. Up here, in D5, it seems like it takes a certified letter to get a response from them.
Quote
Thank you for contacting Caltrans to ask about Botts dots. I'm responding to the email you sent today to Lauren Wonder here at Caltrans District 7 (which includes Los Angeles and Ventura counties).
Contrary to what you may have heard, Caltrans is not discontinuing the use of Botts dots. Caltrans believes this variety of raised pavement marker is an important safety feature of California roadways. But Caltrans does not exclusively use Botts dots for pavement marking.
For example, in some areas you may see thermoplastic striping used. This type of material is heated and applied to road surfaces in a molten state using a mechanical applicator. Immediately after application to the pavement, glass beads are applied to the striping to make it retroreflective. The striping has a slightly raised surface helpful to drivers, yet it is resistant to deformation by traffic.
Thank you for your interest in our state highway system. Please let me know if you have other questions or comments.
Sincerely,
Michael Comeaux
Public Information Officer
Quote from: jrouse on January 04, 2017, 07:15:59 PM
Yes, it is true that Botts dots are going away. They have been (or will be) removed from Caltrans' standard plans. I understand that maintenance is a major reason why. The reason given by the district 7 director is news to me. I'm friends with our traffic engineering branch chief, who is overseeing this, and I'll confirm it with him.
We will be requiring striping to basically have a minimum amount of reflectivity, much like we require for signing. We do not have any such requirement now. Autonomous vehicle manufacturers have been talking with us about improving the visibility of our stripes.
iPhone
jrouse, thanks for the info and for taking the time to check in with your colleague. I know that D7 has used lane markings along PCH in the Malibu area that has a grooved surface to it, which causes a very light rumble when switching lanes. It was definitely more subtle than Botts Dots and made a sound similar to a traditional rumble strip.
Any idea if this could be part of a new spec in addition to the reflectivity?
I talked with our Traffic Engineering branch chief and he did confirm that Botts dots are going away. Interestingly enough, he said FHWA was responsible for the decision because they do not consider the dots as an appropriate form of lane striping. So they can no longer be used. I asked him about the statement made by the District 7 director regarding the impacts of Botts dots on navigation systems and he said he had heard the same thing but it wasn't the reason for eliminating them.
As I mentioned in my earlier post we are going to be issuing standards for striping which will include retro reflectivity requirements. We are phasing out the use of paint and will be going with thermoplastic or tape.
iPhone
Quote from: jrouse on January 11, 2017, 07:02:23 AM
I talked with our Traffic Engineering branch chief and he did confirm that Botts dots are going away. Interestingly enough, he said FHWA was responsible for the decision because they do not consider the dots as an appropriate form of lane striping. So they can no longer be used. I asked him about the statement made by the District 7 director regarding the impacts of Botts dots on navigation systems and he said he had heard the same thing but it wasn't the reason for eliminating them.
As I mentioned in my earlier post we are going to be issuing standards for striping which will include retro reflectivity requirements. We are phasing out the use of paint and will be going with thermoplastic or tape.
I am saddened that Botts Dots are going away. While I understand the importance of retro-reflectivity, the use of Botts Dots provides a sudden audible noise to drivers that they were drifting out of their lane. This will be lost once the dots are gone and I don't think the single reflective markers between the stripes will provide a suitable alternative. As far as the FHWA is concerned, if the dots were used in conjunction with standard striping (which is pretty standard on California's freeways), I don't understand why they would care.
By the way, Nevada and Washington were also users of Botts Dots so I'm guessing they will be phasing them out too.
In cases where Botts Dots are used instead of line striping (as is done in some places), IMO they should be banned, since they lines are difficult to see. But I don't see a reason to ban them if they're used in addition to striping.
Quote from: jrouse on January 11, 2017, 07:02:23 AM
As I mentioned in my earlier post we are going to be issuing standards for striping which will include retro reflectivity requirements. We are phasing out the use of paint and will be going with thermoplastic or tape.
Will thermo/tape be a statewide standard, or will Caltrans still use paint in areas with heavy snowfall?
I also wonder how much cost is a part of this. One would think that thermoplastic/tape is quite a bit cheaper.
Quote from: jrouse on January 11, 2017, 07:02:23 AM
I talked with our Traffic Engineering branch chief and he did confirm that Botts dots are going away. Interestingly enough, he said FHWA was responsible for the decision because they do not consider the dots as an appropriate form of lane striping.
Maybe I'm not familiar enough with Botts dots and their use in California, but the statement would not appear to agree with the current national edition of the MUCTD:
Quote from: Option:
Retroreflective or internally illuminated raised pavement markers, or non-retroreflective raised pavement markers supplemented by retroreflective or internally illuminated markers, may be substituted for markings of other types.
That said, I did see something a couple months ago online that in some presentation FHWA attended FHWA indicated that there may be a revision coming to the MUTCD soon for pavement markings (may have been regarding retroreflectivity requirements)
Quote from: Revive 755 on January 11, 2017, 06:21:04 PM
Quote from: jrouse on January 11, 2017, 07:02:23 AM
I talked with our Traffic Engineering branch chief and he did confirm that Botts dots are going away. Interestingly enough, he said FHWA was responsible for the decision because they do not consider the dots as an appropriate form of lane striping.
Maybe I'm not familiar enough with Botts dots and their use in California, but the statement would not appear to agree with the current national edition of the MUCTD:
Quote from: Option:
Retroreflective or internally illuminated raised pavement markers, or non-retroreflective raised pavement markers supplemented by retroreflective or internally illuminated markers, may be substituted for markings of other types.
That said, I did see something a couple months ago online that in some presentation FHWA attended FHWA indicated that there may be a revision coming to the MUTCD soon for pavement markings (may have been regarding retroreflectivity requirements)
Supplemented. Right there.
WSDOT has mostly done away with botts dots, but they replaced them with, what are in my opinion, superior markings that keep the raised bit, but are exceptionally reflective. They're called raised rib markings (http://www.highwaymarkings.ie/services/road-markings/raised-rib-line), and are used in places with mostly non-snow precipitation (Washington, Oregon, Northern California, the UK, etc). Obviously Southern California doesn't get regular murky precipitation like those places, but I think these would be a worthy replacement regardless:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FiDCq4jA.png&hash=f580f0bd8129d37f60a37b356c663d2868618f0f)
Agreed. I really like the way WSDOT does their lane markings. Going over the lines sounds like you're going over rumble strips, at least if it's a solid line like you're switching into the carpool lane.
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
Come to NY and see lanes totally disappear when it rains.
Quote from: Rothman on January 12, 2017, 08:27:22 AM
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
Come to NY and see lanes totally disappear when it rains.
Yup. Recently, MassDOT started using standard Stimsonite markers placed in grooves, so they can't be removed by plows. They seem to be holding up. Would be nice if NYSDOT did that. The visibility difference along NY/MA 2 at the border is striking.
ODOT can't use Botts Dots because of snow. Plows would tear them up in the first winter.
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
I swear I saw raised rib markings down in Oregon just last week. I must have been mistaken.
Quote from: cl94 on January 12, 2017, 08:45:22 AM
ODOT can't use Botts Dots because of snow. Plows would tear them up in the first winter.
Which ODOT?
Quote from: jakeroot on January 12, 2017, 01:29:53 PM
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
I swear I saw raised rib markings down in Oregon just last week. I must have been mistaken.
Not on the Banfield you didn't.
It's possible on the Baldock or East Portland, though. I'll need to check once the snow melts off.
QuoteQuote from: cl94 on January 12, 2017, 08:45:22 AM
ODOT can't use Botts Dots because of snow. Plows would tear them up in the first winter.
Which ODOT?
Any?
Quote from: Bickendan on January 13, 2017, 03:32:07 AM
Quote from: jakeroot on January 12, 2017, 01:29:53 PM
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
I swear I saw raised rib markings down in Oregon just last week. I must have been mistaken.
Not on the Banfield you didn't.
It's possible on the Baldock or East Portland, though. I'll need to check once the snow melts off.
QuoteQuote from: cl94 on January 12, 2017, 08:45:22 AM
ODOT can't use Botts Dots because of snow. Plows would tear them up in the first winter.
Which ODOT?
Any?
The CA Division of Highways started placing Botts Dots in pavement rebates as early as the mid-60's on facilities within areas that required plowing -- but it was a relatively expensive methodology. However, no applied pavement marker, whether reflective plastic markings or retroreflective thermoplastic strips, will last too long when subject to regular plowing, which tends to gouge below the pavement surface. Replacing such markers or treatments is and likely will be a regular springtime activity for some time to come.
Quote from: Bickendan on January 13, 2017, 03:32:07 AM
Quote from: jakeroot on January 12, 2017, 01:29:53 PM
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
I swear I saw raised rib markings down in Oregon just last week. I must have been mistaken.
Not on the Banfield you didn't.
It's possible on the Baldock or East Portland, though. I'll need to check once the snow melts off.
I only used the 5. I drove straight from Tacoma to Keizer to see family, then straight back north.
Street View clearly shows raised rib markings along the 5 at the Terwilliger Curves (https://goo.gl/8Q1OvT) as well as north of Portland (https://goo.gl/cpe8LU) approaching the Columbia River. They are slightly different raised markers than the kind used by WSDOT, but they are still unmistakably raised rib markings.
Quote from: Bickendan on January 13, 2017, 03:32:07 AM
Quote from: jakeroot on January 12, 2017, 01:29:53 PM
Quote from: cl94 on January 12, 2017, 08:45:22 AM
ODOT can't use Botts Dots because of snow. Plows would tear them up in the first winter.
Which ODOT?
Any?
I was asking cl94 because O(regon)DOT could pull off using Botts Dots (as out of date as they may be) in the Willamette Valley without too much issue. Besides this winter (unusually snowy), Portland doesn't get much snow.
WSDOT no longer uses Botts Dots, but they are still a common sight in the Seattle area. Seattle typically gets more snow than Portland, yet we've been using Botts Dots for some time without too much issue. Some cities, like Bellevue, continue to install Botts Dots for all their road markings, minus stop bars, crosswalk markings and arrows. Typically, plows aren't used to the same extent as they are back east. De-icing solution and salt are generally how roads are kept clear here. Plows are a rare sight in the Seattle area.
Quote from: sparker on January 13, 2017, 04:08:54 AM
Quote from: Bickendan on January 13, 2017, 03:32:07 AM
Quote from: jakeroot on January 12, 2017, 01:29:53 PM
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
I swear I saw raised rib markings down in Oregon just last week. I must have been mistaken.
Not on the Banfield you didn't.
It's possible on the Baldock or East Portland, though. I'll need to check once the snow melts off.
QuoteQuote from: cl94 on January 12, 2017, 08:45:22 AM
ODOT can't use Botts Dots because of snow. Plows would tear them up in the first winter.
Which ODOT?
Any?
The CA Division of Highways started placing Botts Dots in pavement rebates as early as the mid-60's on facilities within areas that required plowing -- but it was a relatively expensive methodology. However, no applied pavement marker, whether reflective plastic markings or retroreflective thermoplastic strips, will last too long when subject to regular plowing, which tends to gouge below the pavement surface. Replacing such markers or treatments is and likely will be a regular springtime activity for some time to come.
Plows are not gouging below the pavement surface. A plow blade skims along the surface at most, with salt or other deicing material taking care of what's left on the surface.
If you're in an area where Botts Dots are used, any other pavement marking should have a very long, useful life.
Quote from: jeffandnicole on January 13, 2017, 06:09:09 AM
Quote from: sparker on January 13, 2017, 04:08:54 AM
Quote from: Bickendan on January 13, 2017, 03:32:07 AM
Quote from: jakeroot on January 12, 2017, 01:29:53 PM
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
I swear I saw raised rib markings down in Oregon just last week. I must have been mistaken.
Not on the Banfield you didn't.
It's possible on the Baldock or East Portland, though. I'll need to check once the snow melts off.
QuoteQuote from: cl94 on January 12, 2017, 08:45:22 AM
ODOT can't use Botts Dots because of snow. Plows would tear them up in the first winter.
Which ODOT?
Any?
The CA Division of Highways started placing Botts Dots in pavement rebates as early as the mid-60's on facilities within areas that required plowing -- but it was a relatively expensive methodology. However, no applied pavement marker, whether reflective plastic markings or retroreflective thermoplastic strips, will last too long when subject to regular plowing, which tends to gouge below the pavement surface. Replacing such markers or treatments is and likely will be a regular springtime activity for some time to come.
Plows are not gouging below the pavement surface. A plow blade skims along the surface at most, with salt or other deicing material taking care of what's left on the surface.
If you're in an area where Botts Dots are used, any other pavement marking should have a very long, useful life.
We've discussed this with you many a time. Plows do indeed scrape up paint. Watch them sometime, you'll be amazed at how much sparking there can be when the blade strikes the pavement repeatedly. Maybe it just doesn't snow enough in South Jersey for you to notice.
Quote from: cl94 on January 12, 2017, 08:45:22 AM
Quote from: Rothman on January 12, 2017, 08:27:22 AM
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
Come to NY and see lanes totally disappear when it rains.
Yup. Recently, MassDOT started using standard Stimsonite markers placed in grooves, so they can't be removed by plows. They seem to be holding up. Would be nice if NYSDOT did that. The visibility difference along NY/MA 2 at the border is striking.
ODOT can't use Botts Dots because of snow. Plows would tear them up in the first winter.
I take it you mean Ohio (the only ODOT I usually think of).
IDOT and ISTHA tend to use the recessed reflectors that have a protective metal casing instead of recessing the entire raised reflector. Of course, after a number of years, the salt can get to them. ISTHA has also gone to recessing the entire lane marking to protect them from plow damage.
Quote from: jakeroot on January 12, 2017, 12:30:08 AM
WSDOT has mostly done away with botts dots, but they replaced them with, what are in my opinion, superior markings that keep the raised bit, but are exceptionally reflective. They're called raised rib markings (http://www.highwaymarkings.ie/services/road-markings/raised-rib-line), and are used in places with mostly non-snow precipitation (Washington, Oregon, Northern California, the UK, etc).
Saw many of these in west Texas last month, both on centerlines and along the shoulders, and the installations looked fairly new. The ones on the shoulder lines are kind of nasty for cyclists, though -- almost as dangerous as full-fledged rumble strips (but aren't as visible because they're covered by paint), although they don't take any actual space from the shoulder, so that's a plus.
Quote from: Brandon on January 13, 2017, 02:02:55 PM
Quote from: jeffandnicole on January 13, 2017, 06:09:09 AM
Quote from: sparker on January 13, 2017, 04:08:54 AM
Quote from: Bickendan on January 13, 2017, 03:32:07 AM
Quote from: jakeroot on January 12, 2017, 01:29:53 PM
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
I swear I saw raised rib markings down in Oregon just last week. I must have been mistaken.
Not on the Banfield you didn't.
It's possible on the Baldock or East Portland, though. I'll need to check once the snow melts off.
QuoteQuote from: cl94 on January 12, 2017, 08:45:22 AM
ODOT can't use Botts Dots because of snow. Plows would tear them up in the first winter.
Which ODOT?
Any?
The CA Division of Highways started placing Botts Dots in pavement rebates as early as the mid-60's on facilities within areas that required plowing -- but it was a relatively expensive methodology. However, no applied pavement marker, whether reflective plastic markings or retroreflective thermoplastic strips, will last too long when subject to regular plowing, which tends to gouge below the pavement surface. Replacing such markers or treatments is and likely will be a regular springtime activity for some time to come.
Plows are not gouging below the pavement surface. A plow blade skims along the surface at most, with salt or other deicing material taking care of what's left on the surface.
If you're in an area where Botts Dots are used, any other pavement marking should have a very long, useful life.
We've discussed this with you many a time. Plows do indeed scrape up paint. Watch them sometime, you'll be amazed at how much sparking there can be when the blade strikes the pavement repeatedly. Maybe it just doesn't snow enough in South Jersey for you to notice.
Yes, we discussed paint. I'm referring to the remark that was made regarding the plow gouging below the road service.
Again...I've mentioned numerous times I'm driving those plows. I see the sparking from the drivers seat of the plow. I see the skids. I see the results of the plowing...the damage to the plows and the roads. I know what the particulars are when it comes to plowing and salting roads (regardless if the plow operator actually abides by those particulars). It's a lot more than setting the plow down and flipping a switch to spread salt.
And yes, I took notice of the pictures people posted. And no doubt some of that could have been caused by plows. Although going back to my original point way back when, the entire northern half of the country isn't getting relined every spring. The entire country of Canada isn't getting relined every spring. In some areas of the country, or some cities, the paint apparently is reapplied each year. But...I allowed the argument to die down.
So, going back to what I just said...Botts Dots aren't used in areas where there's snow. Thus, there should be no concern in regards to winter maintenance and the material used for strips when replacing Botts dots.
Quote from: Brandon on January 13, 2017, 02:05:35 PM
Quote from: cl94 on January 12, 2017, 08:45:22 AM
Quote from: Rothman on January 12, 2017, 08:27:22 AM
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
Come to NY and see lanes totally disappear when it rains.
Yup. Recently, MassDOT started using standard Stimsonite markers placed in grooves, so they can't be removed by plows. They seem to be holding up. Would be nice if NYSDOT did that. The visibility difference along NY/MA 2 at the border is striking.
ODOT can't use Botts Dots because of snow. Plows would tear them up in the first winter.
I take it you mean Ohio (the only ODOT I usually think of).
IDOT and ISTHA tend to use the recessed reflectors that have a protective metal casing instead of recessing the entire raised reflector. Of course, after a number of years, the salt can get to them. ISTHA has also gone to recessing the entire lane marking to protect them from plow damage.
I did mean Ohio, as I also forget there are other ODOTs around.
Quote from: jeffandnicole on January 13, 2017, 03:04:27 PM
The entire country of Canada isn't getting relined every spring.
umm, for all intents and purposes, actually it is.
Quote from: jakeroot on January 13, 2017, 04:29:11 AM
Quote from: Bickendan on January 13, 2017, 03:32:07 AM
Quote from: jakeroot on January 12, 2017, 01:29:53 PM
Quote from: Bickendan on January 12, 2017, 05:57:09 AM
I wish ODOT would adopt those. It's so hard to see the lane markers in the dark when it's raining on Portland freeways.
I swear I saw raised rib markings down in Oregon just last week. I must have been mistaken.
Not on the Banfield you didn't.
It's possible on the Baldock or East Portland, though. I'll need to check once the snow melts off.
I only used the 5. I drove straight from Tacoma to Keizer to see family, then straight back north.
Street View clearly shows raised rib markings along the 5 at the Terwilliger Curves (https://goo.gl/8Q1OvT) as well as north of Portland (https://goo.gl/cpe8LU) approaching the Columbia River. They are slightly different raised markers than the kind used by WSDOT, but they are still unmistakably raised rib markings.
The Minnesota and the Baldock, sounds about right :)
Quote from: AsphaltPlanet on January 13, 2017, 03:45:04 PM
Quote from: jeffandnicole on January 13, 2017, 03:04:27 PM
The entire country of Canada isn't getting relined every spring.
umm, for all intents and purposes, actually it is.
The only places that don't are in western British Columbia, which doesn't get snow.
Quote from: cl94 on January 13, 2017, 05:13:01 PM
Quote from: AsphaltPlanet on January 13, 2017, 03:45:04 PM
Quote from: jeffandnicole on January 13, 2017, 03:04:27 PM
The entire country of Canada isn't getting relined every spring.
umm, for all intents and purposes, actually it is.
The only places that don't are in western British Columbia, which doesn't get snow.
It doesn't see
regular snow a la the rest of Canada. But trust me, it snows just about every winter. 15 inches is average. Inland areas (Abbotsford and east) receive more due to being farther from water. Winter 2016-2017 has been particularly brutal, with snow just about once a week. Some of the fire stations hand out free salt once a week, and people come flocking from all over, like birds, to claim their free salt, since it's become highly desirable this winter.
Quote from: jeffandnicole on January 13, 2017, 03:04:27 PM
So, going back to what I just said...Botts Dots aren't used in areas where there's snow. Thus, there should be no concern in regards to winter maintenance and the material used for strips when replacing Botts dots.
That's not true. Like I just said up-thread, Botts Dots are used (formerly and presently depending on the agency) in Seattle, where it snows basically every year (not like Chicago but we still have plows). Here are some examples of botts dots along some urban Seattle freeways: I-705 in Tacoma (https://goo.gl/LyZhb5), the older stretches of the 520 (https://goo.gl/OjBOZv), formerly along most of 90 (https://goo.gl/YHIWL2) and the 405 (https://goo.gl/GwZZKh). Cities like Bellevue still use them for nearly all of their markings (https://goo.gl/XS9cN1).
Do the plows tear those dots up, or are they low enough that the plows can skim over them?
As far as like painting goes, I'm still in awe that some areas paint so much.
Quote from: jeffandnicole on January 14, 2017, 11:07:12 AM
Do the plows tear those dots up, or are they low enough that the plows can skim over them?
Botts dots? No, plows heavily damage them so they're not used very often in an area that gets any kind of snowfall. Coastal California pretty much never sees snow, so they can be (and were) used with great abandon.
Quote from: coatimundi on January 14, 2017, 12:58:38 PM
Quote from: jeffandnicole on January 14, 2017, 11:07:12 AM
Do the plows tear those dots up, or are they low enough that the plows can skim over them?
Botts dots? No, plows heavily damage them so they're not used very often in an area that gets any kind of snowfall. Coastal California pretty much never sees snow, so they can be (and were) used with great abandon.
What about in the Seattle example above?
http://wsdotblog.blogspot.ca/2008_12_01_archive.html?m=1
https://www.google.ca/amp/s/khbs.relaymedia.com/amp/article/arkansas-highway-department-blames-storm-for-missing-road-reflectors-1/4950813
Quote from: AsphaltPlanet on January 14, 2017, 04:16:47 PM
http://wsdotblog.blogspot.ca/2008_12_01_archive.html?m=1
https://www.google.ca/amp/s/khbs.relaymedia.com/amp/article/arkansas-highway-department-blames-storm-for-missing-road-reflectors-1/4950813
Not sure what relevance the second link has, but I appreciate the former.
I know they like to talk about their snow and it's always a big deal when they get it, but Western Washington (except for the Olympic Mountains) typically gets an amount of snow that would make most other parts of the northern US chuckle. It's usually enough to cover the ground and stick, but it's gone pretty quickly and it doesn't happen very often. Plows just aren't used that much.
Quote from: coatimundi on January 15, 2017, 12:10:45 AM
I know they like to talk about their snow and it's always a big deal when they get it, but Western Washington (except for the Olympic Mountains) typically gets an amount of snow that would make most other parts of the northern US chuckle. It's usually enough to cover the ground and stick, but it's gone pretty quickly and it doesn't happen very often. Plows just aren't used that much.
It's very much dependent on where you are, how much snow you get. Just a couple weeks ago, Tacoma got a flurry of snow, meanwhile, Des Moines (only 10 miles north) got a half foot. It's very random.
The bigger issue really is whether plows are used or not. The fact remains that Seattle does get enough snow to require plowing from time to time. They wouldn't use Botts Dots if they were an issue for the plows. I do see missing Botts Dots from time to time. I assume this is the result of overly-aggressive plowing. I'm guessing WSDOT lays out specific guidelines for plowing over Botts dots.
^ I think it's relevant to point out that snow =/= snow.
The mean temperature in Seattle is, on average, never below freezing. So it's probably very rare that snow in Seattle is going to stay on the ground for any extended period of time anyways, therefore the rubber tipped plows don't actually need to be super effective at removing snow since it will likely melt within a day or two anyways.
This obviously isn't the same in a lot of other areas of the continent (or, even further inland in Washington state), where plows often need to be far more effective at removing the snow from the road, because even with generous salt application, it might not melt immediately.
Quote from: AsphaltPlanet on January 15, 2017, 10:07:49 AM
^ I think it's relevant to point out that snow =/= snow.
I do find it strange that Arkansas would use steel-tipped plows. They're statistically warmer and less snowy than Seattle, so you'd think rubber-tipped plows would be a perfect fit for them (particularly since raised markers are used (to some extent)).
FWIW, even without raised markers, rubber-tipped plows aren't always a bad idea (*in places that don't see much snow*). They don't plow up all the snow, but I don't think they tear up the pavement markings to the same extent as steel-tipped plows. If I were in charge, I'd use rubber-tipped plows to remove most of the snow, and let the sun and cars melt the rest.
Quote from: AsphaltPlanet on January 15, 2017, 10:07:49 AM
The mean temperature in Seattle is, on average, never below freezing. So it's probably very rare that snow in Seattle is going to stay on the ground for any extended period of time anyways, therefore the rubber tipped plows don't actually need to be super effective at removing snow since it will likely melt within a day or two anyways.
That's very true. Some areas see snow stick around for several days (outlying areas), but Seattle proper rarely sees prolonged periods of snowpack (if you could even call it that).
Quote from: AsphaltPlanet on January 15, 2017, 10:07:49 AM
This obviously isn't the same in a lot of other areas of the continent (or, even further inland in Washington state), where plows often need to be far more effective at removing the snow from the road, because even with generous salt application, it might not melt immediately.
My whole point with bringing Seattle up in the first place was because cl94 and j&n suggested that areas with snow don't use raised markers. While that's true for areas with more or less permanent snowpack, Seattle (which gets a hell of a lot more snow than Los Angeles or San Francisco) does use raised markers, even with the constant threat of snow. The climate is unique in that, as you said, plowing all the way to the surface isn't generally necessary because there's enough cars driving around to melt the snow from the street by mid-day (snow simply doesn't last long enough to present an issue).
If there's a prolonged period of snow (more than three days), and the temperature stays below freezing, that's when you start to see some issues. Because the plow cannot reach all the way to the surface, there's always some sort of snow or ice on the ground (whereas places like Minneapolis or Buffalo might be able to get all the way to the ground with their steel-tipped plows, thus no threat of snow or ice buildup). Before cold nights (snow expected or not), de-icer trucks roam the streets of Puget Sound to prevent freezing. This may also prevent snow from sticking, but I'm not sure how it works.
Quote from: jakeroot on January 15, 2017, 04:16:19 PM
Before cold nights (snow expected or not), de-icer trucks roam the streets of Puget Sound to prevent freezing. This may also prevent snow from sticking, but I'm not sure how it works.
This is why brine has become very popular. It helps melt that first 1/2 inch or inch of snow in the first hour it falls, and from my experiences tends to make snow removal a bit easier. But once it gets wet, then it loses its effectiveness. So after an hour, anything new that falls will stick or ice up. Since black ice could form from moister in the air, brine helps against that too.
If a storm misses the area, the brine sticks to the road until its wet. Brine laid today will still be there next week if it doesn't get wet.
The worst cases of brine being used is when it's going to rain before changing over. The rain washes it away in minutes, rendering it useless. Granted, it's cheap, and it's usually applied during the daytime when the employees are at work anyway, but it's still a waste.
Quote from: jakeroot on January 15, 2017, 04:16:19 PM
Quote from: AsphaltPlanet on January 15, 2017, 10:07:49 AM
^ I think it's relevant to point out that snow =/= snow.
I do find it strange that Arkansas would use steel-tipped plows. They're statistically warmer and less snowy than Seattle, so you'd think rubber-tipped plows would be a perfect fit for them (particularly since raised markers are used (to some extent)).
FWIW, even without raised markers, rubber-tipped plows aren't always a bad idea. They don't plow up all the snow, but I don't think they tear up the pavement markings to the same extent as steel-tipped plows. If I were in charge, I'd use rubber-tipped plows to remove most of the snow, and let the sun and cars melt the rest.
It doesn't always work. Remember that -20F you discussed in the weather thread in Minneapolis? Nothing melts at those temperatures, and we can have them for days, even weeks on end in the Upper Midwest/Great Lakes. As an example, we had a season a few years ago we termed "Chiberia". And then you have the insane amounts of snow that places like the Keweenaw Peninsula get.
http://www.mnn.com/earth-matters/climate-weather/blogs/greetings-from-chiberia-11-surreal-shots-of-the-windy-citys
https://en.wikipedia.org/wiki/Early_2014_North_American_cold_wave#Record_cold_temperatures
https://www.dnainfo.com/chicago/20140106/chicago/chicago-extreme-cold-temperatures-plunge-chiberia
http://www.uppermichiganssource.com/content/news/Snow-mounds-pile-higher-in-Houghton-County-410679035.html
http://www.upmatters.com/news/local-news/snow-removal-in-keweenaw-county-snowiest-in-the-state/611894351
http://www.mininggazette.com/news/2017/01/keweenaw-gets-dumped-on-while-rest-of-up-spared/
Quote from: Brandon on January 15, 2017, 05:06:08 PM
Quote from: jakeroot on January 15, 2017, 04:16:19 PM
Quote from: AsphaltPlanet on January 15, 2017, 10:07:49 AM
^ I think it's relevant to point out that snow =/= snow.
I do find it strange that Arkansas would use steel-tipped plows. They're statistically warmer and less snowy than Seattle, so you'd think rubber-tipped plows would be a perfect fit for them (particularly since raised markers are used (to some extent)).
FWIW, even without raised markers, rubber-tipped plows aren't always a bad idea. They don't plow up all the snow, but I don't think they tear up the pavement markings to the same extent as steel-tipped plows. If I were in charge, I'd use rubber-tipped plows to remove most of the snow, and let the sun and cars melt the rest.
It doesn't always work. Remember that -20F you discussed in the weather thread in Minneapolis? Nothing melts at those temperatures, and we can have them for days, even weeks on end in the Upper Midwest/Great Lakes. As an example, we had a season a few years ago we termed "Chiberia". And then you have the insane amounts of snow that places like the Keweenaw Peninsula get.
http://www.mnn.com/earth-matters/climate-weather/blogs/greetings-from-chiberia-11-surreal-shots-of-the-windy-citys
https://en.wikipedia.org/wiki/Early_2014_North_American_cold_wave#Record_cold_temperatures
https://www.dnainfo.com/chicago/20140106/chicago/chicago-extreme-cold-temperatures-plunge-chiberia
http://www.uppermichiganssource.com/content/news/Snow-mounds-pile-higher-in-Houghton-County-410679035.html
http://www.upmatters.com/news/local-news/snow-removal-in-keweenaw-county-snowiest-in-the-state/611894351
http://www.mininggazette.com/news/2017/01/keweenaw-gets-dumped-on-while-rest-of-up-spared/
Nicely, snow/ice with temps that cold actually isn't too bad to drive/walk on. It can't really melt, so traction is pretty good. When ice gets that small liquid layer on it is when it's slippery and dangerous.
Quote from: Brandon on January 15, 2017, 05:06:08 PM
Quote from: jakeroot on January 15, 2017, 04:16:19 PM
Quote from: AsphaltPlanet on January 15, 2017, 10:07:49 AM
^ I think it's relevant to point out that snow =/= snow.
I do find it strange that Arkansas would use steel-tipped plows. They're statistically warmer and less snowy than Seattle, so you'd think rubber-tipped plows would be a perfect fit for them (particularly since raised markers are used (to some extent)).
FWIW, even without raised markers, rubber-tipped plows aren't always a bad idea. They don't plow up all the snow, but I don't think they tear up the pavement markings to the same extent as steel-tipped plows. If I were in charge, I'd use rubber-tipped plows to remove most of the snow, and let the sun and cars melt the rest.
It doesn't always work. Remember that -20F you discussed in the weather thread in Minneapolis? Nothing melts at those temperatures, and we can have them for days, even weeks on end in the Upper Midwest/Great Lakes. As an example, we had a season a few years ago we termed "Chiberia". And then you have the insane amounts of snow that places like the Keweenaw Peninsula get.
Whoops, my mistake. I meant to specificy that rubber-tipped plows might not be a bad idea, regardless if there's raised markers or not, in areas that don't see much snow (evidently, Arkansas uses steel-tipped plows). There's no doubting the benefits of steel in exceptionally snowy areas.
I've edited my post accordingly.
Quote from: myosh_tino on January 11, 2017, 04:05:29 PM
I am saddened that Botts Dots are going away. While I understand the importance of retro-reflectivity, the use of Botts Dots provides a sudden audible noise to drivers that they were drifting out of their lane. This will be lost once the dots are gone and I don't think the single reflective markers between the stripes will provide a suitable alternative.
Indeed. And just at the time when there are more and more distractions for drivers in their cars when this little device would perform a big help to maintaining safety.
Quote from: mrsman on January 16, 2017, 08:12:51 AM
Quote from: myosh_tino on January 11, 2017, 04:05:29 PM
I am saddened that Botts Dots are going away. While I understand the importance of retro-reflectivity, the use of Botts Dots provides a sudden audible noise to drivers that they were drifting out of their lane. This will be lost once the dots are gone and I don't think the single reflective markers between the stripes will provide a suitable alternative.
Indeed. And just at the time when there are more and more distractions for drivers in their cars when this little device would perform a big help to maintaining safety.
There are other forms of raised markers, and I don't believe D7 ever stated that they were moving away from raised markers (just Botts dots).
Quote from: jakeroot on January 16, 2017, 12:57:51 PM
Quote from: mrsman on January 16, 2017, 08:12:51 AM
Quote from: myosh_tino on January 11, 2017, 04:05:29 PM
I am saddened that Botts Dots are going away. While I understand the importance of retro-reflectivity, the use of Botts Dots provides a sudden audible noise to drivers that they were drifting out of their lane. This will be lost once the dots are gone and I don't think the single reflective markers between the stripes will provide a suitable alternative.
Indeed. And just at the time when there are more and more distractions for drivers in their cars when this little device would perform a big help to maintaining safety.
There are other forms of raised markers, and I don't believe D7 ever stated that they were moving away from raised markers (just Botts dots).
I think it would be better to just use reflective markers. More common and more visible.
Quote from: cl94 on January 16, 2017, 01:14:56 PM
Quote from: jakeroot on January 16, 2017, 12:57:51 PM
Quote from: mrsman on January 16, 2017, 08:12:51 AM
Quote from: myosh_tino on January 11, 2017, 04:05:29 PM
I am saddened that Botts Dots are going away. While I understand the importance of retro-reflectivity, the use of Botts Dots provides a sudden audible noise to drivers that they were drifting out of their lane. This will be lost once the dots are gone and I don't think the single reflective markers between the stripes will provide a suitable alternative.
Indeed. And just at the time when there are more and more distractions for drivers in their cars when this little device would perform a big help to maintaining safety.
There are other forms of raised markers, and I don't believe D7 ever stated that they were moving away from raised markers (just Botts dots).
I think it would be better to just use reflective markers. More common and more visible.
What about those raised markers (https://www.aaroads.com/forum/index.php?topic=19469.msg2198641#msg2198641) I suggested on the last page? Too expensive?
Quote from: cl94 on January 16, 2017, 01:14:56 PM
Quote from: jakeroot on January 16, 2017, 12:57:51 PM
Quote from: mrsman on January 16, 2017, 08:12:51 AM
Quote from: myosh_tino on January 11, 2017, 04:05:29 PM
I am saddened that Botts Dots are going away. While I understand the importance of retro-reflectivity, the use of Botts Dots provides a sudden audible noise to drivers that they were drifting out of their lane. This will be lost once the dots are gone and I don't think the single reflective markers between the stripes will provide a suitable alternative.
Indeed. And just at the time when there are more and more distractions for drivers in their cars when this little device would perform a big help to maintaining safety.
There are other forms of raised markers, and I don't believe D7 ever stated that they were moving away from raised markers (just Botts dots).
I think it would be better to just use reflective markers. More common and more visible.
But they don't provide enough of an audible alert or a tactile feel to let you know you're drifting into another lane.
Sure, they do. Just yesterday, I ran over them on I-91 since I was driving lazy on a route I have travelled hundreds of times before. You still get enough of the bump sound.
Having lived in California, I always thought the huge dots were overkill.
Article from Sacramento Bee about Botts Dots possibly going away... and it does mention automated vehicles as a reason.
http://www.sacbee.com/news/local/transportation/article127811959.html
QuoteCalifornia's iconic Botts Dot, the bump that warns you're drifting out of your lane, has reached the end of its road.
After more than a half century of service, the safety device created by Elbert Botts in a Sacramento lab and once described by a state official as a loyal old dog, is expected to be relieved of duty sometime this year. The classic white ceramic dot, a notable innovation in its day, appears to be a bad fit as a lane marker in the emerging new world of driverless cars that rely on cameras, radar and computers to "read" and understand lane lines.
Although automated vehicles can be taught to "see" a variety of lane markings, including dots, federal officials and the vehicle industry say they want more uniformity nationally on lane lines. Given that few states outside of California still employ the original cookie-shaped ceramic Botts Dot, the writing is on the wall. ...
That may mean more use of thermoplastic lane lines, a material used by Caltrans and other states that looks at a glance like paint, but is thick like cake icing, and is reflective and more durable than paint. (In snow areas, though, Caltrans and other states use regular paint and reflective markers embedded in divots below the road surface where they won't get scraped away by snowplows.)
Duper Tong, chief of Caltrans' Office of Traffic Engineering, said the state likely will formally decide this year to begin removing the Botts Dots, possibly more than 20 million of them, from state highways and freeways. The dots would be removed over time when crews do road resurfacing projects, he said.
Automated cars aren't the only reason for the end of the dot era, Tong said. The dots, which are typically glued to the pavement in rows of four, crumble and break loose too frequently under heavier truck traffic, he said. Caltrans officials say it is risky for maintenance crews to replace them amid speeding freeway traffic.
Tong cited the state's aging population as another factor. The leading edge of the baby boom generation is now turning 70. Tong said reflective thermoplastic lines and newer reflective plastic markers are easier for older eyes to see. Although white and ceramic, Botts Dots are not considered reflective.
The dots already have largely disappeared in some areas of the state. Caltrans has largely done away with Botts Dots on Sacramento Valley highways in favor of brighter striping materials.
Sacramento city and county also phased out Botts Dots a few years ago on surface streets in favor of plastic "paint" and reflective markers, although you can still occasionally see a few leftover Botts Dots stubbornly sticking to the pavement here and there.
The dots have some sentimental value in Sacramento. They were invented in 1953 in a Caltrans test lab here headed by chemical engineer Elbert Botts. Caltrans was looking for a replacement for painted lines, which were beginning to wear out too quickly on multilane freeways, where vehicles moved from lane to lane.
Botts and his group initially tried nailing the dots into the pavement, but the nails came loose. The state came up with an epoxy to glue the dots down.
Rumors that Botts himself received a penny royalty for every dot the state used are not true, according to the urban legend-busting Snopes website. In fact, Botts is said to have died in 1962, before the state began widespread use of his namesake domed dots.
The dots quickly became useful as a safety tool in more ways than Caltrans envisioned, at least according to some drivers.
Caltrans engineers say they intended the dot to be merely a visual lane delineator. But drivers discovered the rows of dots caused a distinctive ka-thump sound when tires passed over them, offering an audible warning to drivers that their car was drifting out of its lane. Some drivers said they could even feel the vibration.
Tong and other Caltrans officials say they believe the thumping sound is at best a minimal safety enhancement. They point to a Caltrans study in the 1990s on several highways, including the Capital City Freeway in Sacramento, that suggested crash numbers are the same with dots as they are with newer reflective lane lines and markers. ...
Tong said the state also plans to use more of what it calls "Oreo" or "contrast striping," a white line flanked by black stripes. That striping, now in use on some Sacramento-area freeways, provides better visibility on light concrete road surfaces.
I admit to only skimming the thread, but Botts dots providing an audible noise that you're drifting into another lane seems like a safety feature. Will any replacement offer such a noise?
Quote from: Quillz on January 21, 2017, 05:14:35 PM
I admit to only skimming the thread, but Botts dots providing an audible noise that you're drifting into another lane seems like a safety feature. Will any replacement offer such a noise?
I know I keep bringing this up over and over again, but no one's voiced a negative opinion of them yet, so I'm going to continue doing so.
Raised rib markings (http://www.highwaymarkings.ie/services/road-markings/raised-rib-line) are now used in several West coast locales that experience dark, rainy weather. They have replaced botts dots here in the Seattle area; San Francisco has started using them as well; they are also ubiquitous across the UK and Ireland (note that all three have similar climates), and likely the rest of Europe as well.
Their prime advantage of being very visible in rainy/dark/murky situations may not be fully realized by Southern California, but they provide audible feedback like botts dots, but they look more like traditional lane lines, so they'd work better with self-driving vehicles.
Quote from: jakeroot on January 21, 2017, 08:28:41 PM
Quote from: Quillz on January 21, 2017, 05:14:35 PM
I admit to only skimming the thread, but Botts dots providing an audible noise that you're drifting into another lane seems like a safety feature. Will any replacement offer such a noise?
I know I keep bringing this up over and over again, but no one's voiced a negative opinion of them yet, so I'm going to continue doing so.
Raised rib markings (http://www.highwaymarkings.ie/services/road-markings/raised-rib-line) are now used in several West coast locales that experience dark, rainy weather. They have replaced botts dots here in the Seattle area; San Francisco has started using them as well; they are also ubiquitous across the UK and Ireland (note that all three have similar climates), and likely the rest of Europe as well.
Their prime advantage of being very visible in rainy/dark/murky situations may not be fully realized by Southern California, but they provide audible feedback like botts dots, but they look more like traditional lane lines, so they'd work better with self-driving vehicles.
Sounds like a good replacement. One place that could use them is I-5 through the Sierra Pelona. I was just there last week and the lane striping is awful... No dots, faded lines, thick fog.
Quote from: jakeroot on January 21, 2017, 08:28:41 PM
Raised rib markings (http://www.highwaymarkings.ie/services/road-markings/raised-rib-line) are now used in several West coast locales that experience dark, rainy weather. They have replaced botts dots here in the Seattle area; San Francisco has started using them as well; they are also ubiquitous across the UK and Ireland (note that all three have similar climates), and likely the rest of Europe as well.
Their prime advantage of being very visible in rainy/dark/murky situations may not be fully realized by Southern California, but they provide audible feedback like botts dots, but they look more like traditional lane lines, so they'd work better with self-driving vehicles.
I suspect those type of markings weren't even being considered because you could accomplish the same thing by combining Botts Dots with traditional lane lines which, for the most part, is what's being done on Bay Area freeways. I have not seen a Botts Dots only approach to striping in quite some time although that practice is still common among local municipalities.
Quote from: myosh_tino on January 21, 2017, 11:42:54 PM
Quote from: jakeroot on January 21, 2017, 08:28:41 PM
Raised rib markings (http://www.highwaymarkings.ie/services/road-markings/raised-rib-line) are now used in several West coast locales that experience dark, rainy weather. They have replaced botts dots here in the Seattle area; San Francisco has started using them as well; they are also ubiquitous across the UK and Ireland (note that all three have similar climates), and likely the rest of Europe as well.
Their prime advantage of being very visible in rainy/dark/murky situations may not be fully realized by Southern California, but they provide audible feedback like botts dots, but they look more like traditional lane lines, so they'd work better with self-driving vehicles.
I suspect those type of markings weren't even being considered because you could accomplish the same thing by combining Botts Dots with traditional lane lines which, for the most part, is what's being done on Bay Area freeways. I have not seen a Botts Dots only approach to striping in quite some time although that practice is still common among local municipalities.
They're similar, but different. I assure you that raised rib markings wouldn't have been developed if they achieved the same result as Botts dots + painted lines.
I think the key difference is that raised rib markings are both shorter and more numerous. This is important because a tire has less time to get in that space between the raised markings, making them less
likely to get ripped up susceptible to wear.
Quote from: jrouse on January 11, 2017, 07:02:23 AM
I talked with our Traffic Engineering branch chief and he did confirm that Botts dots are going away. Interestingly enough, he said FHWA was responsible for the decision because they do not consider the dots as an appropriate form of lane striping. So they can no longer be used. I asked him about the statement made by the District 7 director regarding the impacts of Botts dots on navigation systems and he said he had heard the same thing but it wasn't the reason for eliminating them.
As I mentioned in my earlier post we are going to be issuing standards for striping which will include retro reflectivity requirements. We are phasing out the use of paint and will be going with thermoplastic or tape.
iPhone
Valley locations in New Mexico (notably Albuquerque, Alamogordo and Las Cruces) originally used Botts Dots on at least some of their roads, but Albuquerque has since done away with the practice of installing raised pavement markings on its streets. There are still a few roads in and around Albuquerque with old pavement that have Botts Dots, but these are being eliminated when such roads are resurfaced and restriped with reflective paint. On my recent trips (within the last year) to Alamogordo and Las Cruces, I noticed both cities continue to install Botts Dots and reflective pavement markers on their streets to mark travel lanes. I have also noticed on recent trips that NMDOT is installing reflective pavement markers embedded into recessed pockets to mark travel lanes on resurfaced sections of I-25 and I-40. I started seeing the reflective pavement markers on I-25 between Las Cruces and Socorro a couple of years ago, but on recent trips I noticed newly resurfaced sections of I-40 from Santa Rosa to the Texas state line and on I-25 over Glorieta Pass having recessed reflective pavement markers recently installed.
Quote from: mrsman on January 16, 2017, 08:12:51 AM
Quote from: myosh_tino on January 11, 2017, 04:05:29 PM
I am saddened that Botts Dots are going away. While I understand the importance of retro-reflectivity, the use of Botts Dots provides a sudden audible noise to drivers that they were drifting out of their lane. This will be lost once the dots are gone and I don't think the single reflective markers between the stripes will provide a suitable alternative.
Indeed. And just at the time when there are more and more distractions for drivers in their cars when this little device would perform a big help to maintaining safety.
The raised reflectors make noise.. Probably just as much as botts dots... Florida state roads have the raised relectors everywhere.. Most counties use them on arterials on rural highways too.. Granted we do not have snow
Pavement groves are used on rural higways in addition to the relflectors
LGMS428
Quote from: jwolfer on January 24, 2017, 03:52:57 PM
Quote from: mrsman on January 16, 2017, 08:12:51 AM
Quote from: myosh_tino on January 11, 2017, 04:05:29 PM
I am saddened that Botts Dots are going away. While I understand the importance of retro-reflectivity, the use of Botts Dots provides a sudden audible noise to drivers that they were drifting out of their lane. This will be lost once the dots are gone and I don't think the single reflective markers between the stripes will provide a suitable alternative.
Indeed. And just at the time when there are more and more distractions for drivers in their cars when this little device would perform a big help to maintaining safety.
The raised reflectors make noise.. Probably just as much as botts dots... Florida state roads have the raised relectors everywhere.. Most counties use them on arterials on rural highways too.. Granted we do not have snow
Pavement groves are used on rural higways in addition to the relflectors
A single raised reflector makes just as much noise as a single Botts Dot. However, the typical application of Botts Dots results in more noise when changing lanes because more raised pavement markers are used overall.
For example, Nevada DOT design standards for a broken white line on a freeway using both reflector and Botts Dot RPMs (10' line, 30' gap) looks something like this:
[] () () () [] () () ()
Contrast with NDOT design standard for broken white line in rural areas with painted line and reflector RPMs (10' line, 30' gap) looks like this:
------------- [] -------------
Quote from: jakeroot on January 22, 2017, 12:16:05 AM
Quote from: myosh_tino on January 21, 2017, 11:42:54 PM
Quote from: jakeroot on January 21, 2017, 08:28:41 PM
Raised rib markings (http://www.highwaymarkings.ie/services/road-markings/raised-rib-line) are now used in several West coast locales that experience dark, rainy weather. They have replaced botts dots here in the Seattle area; San Francisco has started using them as well; they are also ubiquitous across the UK and Ireland (note that all three have similar climates), and likely the rest of Europe as well.
Their prime advantage of being very visible in rainy/dark/murky situations may not be fully realized by Southern California, but they provide audible feedback like botts dots, but they look more like traditional lane lines, so they'd work better with self-driving vehicles.
I suspect those type of markings weren't even being considered because you could accomplish the same thing by combining Botts Dots with traditional lane lines which, for the most part, is what's being done on Bay Area freeways. I have not seen a Botts Dots only approach to striping in quite some time although that practice is still common among local municipalities.
They're similar, but different. I assure you that raised rib markings wouldn't have been developed if they achieved the same result as Botts dots + painted lines.
I think the key difference is that raised rib markings are both shorter and more numerous. This is important because a tire has less time to get in that space between the raised markings, making them less likely to get ripped up susceptible to wear.
Up here, we use rib markings (rumble strips) that are cut into the pavement rather than raised up from the pavement along the edges of the road and sometimes down the center of an undivided road. It seems to be rather effective.