D7 Removing "Botts Dots"??

[jakeroot]

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 I suggested on the last page? Too expensive?

[myosh_tino]

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.

[Rothman]

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.

[andy3175]

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

California'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.

[Quillz]

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?

[jakeroot]

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 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.

[Quillz]

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 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.

[myosh_tino]

Raised rib markings 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.

[jakeroot]

Raised rib markings 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.

[abqtraveler]

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.

[jwolfer]

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

[roadfro]

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:

          -------------                   []                   -------------

[Brandon]

Raised rib markings 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.