There as been talk of Caltrans phasing out Botts Dots in other discussions. I've also noticed that District 11 (San Diego) has been experimenting with using 6-inch wide lane lines.
On 19 May 2017 Caltrans issued the following memo:
Implementation of Six-Inch Wide Traffic Lines and Discontinuing Use of Non-Reflective Raised Pavement Markers (http://www.dot.ca.gov/trafficops/policy/memo_6-in-wide-traffic-lines_051917.pdf")
All new lanelines, edgelines, and centerlines will be 6 inches wide instead of the current 4 inches. When lines are refreshed during maintenance, they will be replaced with the new wider lines. An exception is made for lines with reflectors on either side (e.g. a double yellow line) because the wider lines will not fit without moving the reflectors.
The standard plans will be updated in July to reflect these changes.
This rescinds the previous directive which allowed for thermoplastic striping to be placed over Botts Dots:
http://www.dot.ca.gov/trafficops/policy/00-02.pdf (http://www.dot.ca.gov/trafficops/policy/00-02.pdf)
Overall, this should increase lane line visibility. Wider shoulder lines have been shown to help reduce the rate of vehicles running off the road. However, I've always found the dots to be helpful with keeping vehicles from drifting out of a lane.
Interestingly enough, the just released project plans for the northbound I-680 express lane from 237 to 84 calls for the use of Botts Dots on the lane lines. The general purpose lane lines use Botts Dots on top of 4-inch wide thermoplastic striping while the express lane lines use Botts Dots on top of 8-inch wide thermoplastic striping. Whether this gets changed with an addendum remains to be seen.
Personally I can't stand the botts dots make, I'll be glad see them replaced with a wider side stripe. Those things get frustraing as all hell on mountain roads like 245 or 198.
Quote from: Max Rockatansky on August 16, 2017, 12:47:40 PM
Those things get frustraing as all hell on mountain roads like 245 or 198.
How so? I would think the sound they make when you drive over them is extremely useful on mountain roads because it gives instant feedback when you drift over the centerline.
On a related note, double-yellow lines will remain 4 inches wide.
Quote from: myosh_tino on August 16, 2017, 01:00:26 PM
Quote from: Max Rockatansky on August 16, 2017, 12:47:40 PM
Those things get frustraing as all hell on mountain roads like 245 or 198.
How so? I would think the sound they make when you drive over them is extremely useful on mountain roads because it gives instant feedback when you drift over the centerline.
On a related note, double-yellow lines will remain 4 inches wide.
Really it's just a personal nitpick, I should clarify they do their job just fine. However in the instance of 245 there is a section between 180 and Dunlap Road where the width of the highway might 13-15 feet in places. Rather than slathering botts dots all over I'd rather see Caltrans go to a single-lane configuration like a 35, 146, 36, 4, or 172 have in use with accompanying signage..."One-Lane Road Ahead" on a big yellow advisory sign tends to grab attention. It does get a little frustrating when you can't help but be on the center line and you're getting pounded by botts dots.
Quote from: myosh_tino on August 16, 2017, 01:00:26 PM
On a related note, double-yellow lines will remain 4 inches wide.
Yeah, existing double yellow lines will remain 4 inches wide due to the placement of reflectors on either side of the lines. However, installations on new pavement will be 6 inches with a 3 inch gap in the middle. The updated design for Detail 22 is shown here: Revised Standard Plan A20A (http://www.dot.ca.gov/hq/esc/oe/project_plans/Errata/Errata-2015/2015_StdPln_Errata_No.5/rspa20a.pdf).
Fixed link. —Roadfro
An article on this appeared in Mr. Roadshow:
http://www.mercurynews.com/2017/08/23/caltrans-says-bye-bye-to-botts-dots/
QuoteTo the dismay of most California drivers, it's now official. Those popular Botts' Dots will disappear from state roadways.
Caltrans has approved removing the nonreflective pavement markers that for the last five decades have warned motorists when they veer out of their lanes. The 20 million now in use will be replaced over time with new markers that are cheaper and safer to install and can better guide the thousands of self-driving cars that are in our future. ...
Last week the state sent out notices that it is discontinuing use of nonreflective pavement markers and is increasing the width of all 4-inch wide traffic lines to 6-inch wide lines on highways.
California is one of just four states using Botts' Dots. New federal standards have caused most to say farewell to the devices that were the idea of Elbert Botts, a Caltrans chemical engineer who once taught at San Jose State University.
But the move is not popular. Of the first 74 comments Caltrans received, all opposed getting rid of the bumps that have given motorists a gentle rumble as they unknowingly cross into another lane.
^ I'm curious... The article/interview says that California is one of only 4 states still using Botts Dots. I know Nevada is another. What are the other two states?
Quote from: roadfro on August 24, 2017, 01:31:40 AM
^ I'm curious... The article/interview says that California is one of only 4 states still using Botts Dots. I know Nevada is another. What are the other two states?
Hawaii is one.
Mike
Quote from: mgk920 on August 24, 2017, 09:42:53 AM
Quote from: roadfro on August 24, 2017, 01:31:40 AM
^ I'm curious... The article/interview says that California is one of only 4 states still using Botts Dots. I know Nevada is another. What are the other two states?
Hawaii is one.
Mike
I believe Washington State is the other one.
Quote from: jeffe on August 25, 2017, 04:13:24 AM
I believe Washington State is the other one.
Most likely. There's a lot of roads in Washington (particularly on the western side of the state) that just use raised pavement markings for striping instead of paint/thermoplastic.
https://en.m.wikipedia.org/wiki/Elbert_Dysart_Botts
Interestingly the first Botts dots was tested in West Sacramento and Vacaville according to this article.
Quote from: andy3175 on August 24, 2017, 01:12:00 AM
An article on this appeared in Mr. Roadshow:
http://www.mercurynews.com/2017/08/23/caltrans-says-bye-bye-to-botts-dots/
QuoteTo the dismay of most California drivers, it's now official. Those popular Botts' Dots will disappear from state roadways.
Caltrans has approved removing the nonreflective pavement markers that for the last five decades have warned motorists when they veer out of their lanes. The 20 million now in use will be replaced over time with new markers that are cheaper and safer to install and can better guide the thousands of self-driving cars that are in our future. ...
Last week the state sent out notices that it is discontinuing use of nonreflective pavement markers and is increasing the width of all 4-inch wide traffic lines to 6-inch wide lines on highways.
California is one of just four states using Botts' Dots. New federal standards have caused most to say farewell to the devices that were the idea of Elbert Botts, a Caltrans chemical engineer who once taught at San Jose State University.
But the move is not popular. Of the first 74 comments Caltrans received, all opposed getting rid of the bumps that have given motorists a gentle rumble as they unknowingly cross into another lane.
According to everything I've read, the elimination of Botts Dots and the 6-inch striping only applies to highways under Caltrans' control. There are many local municipalities who use Botts Dots to mark centerlines and lane lines. I would suspect they would continue to do so.
Quote from: roadfro on August 24, 2017, 01:31:40 AM
^ I'm curious... The article/interview says that California is one of only 4 states still using Botts Dots. I know Nevada is another. What are the other two states?
Oregon was using them when I lived there about 15 years ago. I'm not sure if they've phased them out too or not.
Quote from: i-215 on August 25, 2017, 05:23:49 PM
Quote from: roadfro on August 24, 2017, 01:31:40 AM
^ I'm curious... The article/interview says that California is one of only 4 states still using Botts Dots. I know Nevada is another. What are the other two states?
Oregon was using them when I lived there about 15 years ago. I'm not sure if they've phased them out too or not.
Oregon seems to be using raised rib markings now, along with Washington. Those are my favorite kind of striping.
US-50 in Sacramento has no Botts Dots as of August 2017.
I wonder what this will mean for HOV/HOT lane markings, when access is permitted. Doesn't the MUTCD require/recommend that preferential lane markings be double the width than those of normal lane markings? If so, I wonder whether Caltrans will widen the typical 8-inch wide stripe to a hearty 12 inches, or if they will employ a new design in adjustment to this update.
Quote from: joshI5 on August 30, 2017, 07:25:53 PM
I wonder what this will mean for HOV/HOT lane markings, when access is permitted. Doesn't the MUTCD require/recommend that preferential lane markings be double the width than those of normal lane markings? If so, I wonder whether Caltrans will widen the typical 8-inch wide stripe to a hearty 12 inches, or if they will employ a new design in adjustment to this update.
MUTCD Sec. 3A-06, standard: A normal line is 4-6 inches wide. A wide line is at least twice the width of a normal line.
MUTCD Sec. 3D-02, standard: For buffer-separated and contiguous preferential lanes, the dividing lane line(s) are to be wide white lines.
Quote from: roadfro on August 30, 2017, 10:54:28 PM
Quote from: joshI5 on August 30, 2017, 07:25:53 PM
I wonder what this will mean for HOV/HOT lane markings, when access is permitted. Doesn't the MUTCD require/recommend that preferential lane markings be double the width than those of normal lane markings? If so, I wonder whether Caltrans will widen the typical 8-inch wide stripe to a hearty 12 inches, or if they will employ a new design in adjustment to this update.
MUTCD Sec. 3A-06, standard: A normal line is 4-6 inches wide. A wide line is at least twice the width of a normal line.
MUTCD Sec. 3D-02, standard: For buffer-separated and contiguous preferential lanes, the dividing lane line(s) are to be wide white lines.
I guess the key words are "at least twice the width" meaning Caltrans can use 6-inch normal lines and 8-inch wide lines. Any ideas how wide the lines on the I-15 Express Lanes in Las Vegas are?
Note: "at least twice" meaning 2x or more... 6-inch normal means wide lines must be at least 12 inches... wasn't sure what I was thinking when I wrote the above post... sorry!
Quote from: myosh_tino on August 31, 2017, 11:43:21 AM
Quote from: roadfro on August 30, 2017, 10:54:28 PM
Quote from: joshI5 on August 30, 2017, 07:25:53 PM
I wonder what this will mean for HOV/HOT lane markings, when access is permitted. Doesn't the MUTCD require/recommend that preferential lane markings be double the width than those of normal lane markings? If so, I wonder whether Caltrans will widen the typical 8-inch wide stripe to a hearty 12 inches, or if they will employ a new design in adjustment to this update.
MUTCD Sec. 3A-06, standard: A normal line is 4-6 inches wide. A wide line is at least twice the width of a normal line.
MUTCD Sec. 3D-02, standard: For buffer-separated and contiguous preferential lanes, the dividing lane line(s) are to be wide white lines.
I guess the key words are "at least twice the width" meaning Caltrans can use 6-inch normal lines and 8-inch wide lines. Any ideas how wide the lines on the I-15 Express Lanes in Las Vegas are?
In the north, NDOT uses a wider width for normal lines on all freeways, which I believe is 6 inches. But I think the I-15 express lane lines are a bit wider (not around them enough to directly compare though), so I'd guess they use 8 inches.
Just came across some very recent 6" installation. This is on the southbound side of the Santa Ana Freeway I-5 just south of downtown LA. Botts dots have clearly been deliberately removed.
(https://uploads.tapatalk-cdn.com/20170911/30cebaa53e39fbdbea27e0b724eba005.jpg)
Quote from: roadfro on August 30, 2017, 10:54:28 PM
Quote from: joshI5 on August 30, 2017, 07:25:53 PM
I wonder what this will mean for HOV/HOT lane markings, when access is permitted. Doesn't the MUTCD require/recommend that preferential lane markings be double the width than those of normal lane markings? If so, I wonder whether Caltrans will widen the typical 8-inch wide stripe to a hearty 12 inches, or if they will employ a new design in adjustment to this update.
MUTCD Sec. 3A-06, standard: A normal line is 4-6 inches wide. A wide line is at least twice the width of a normal line.
MUTCD Sec. 3D-02, standard: For buffer-separated and contiguous preferential lanes, the dividing lane line(s) are to be wide white lines.
As of right now, Caltrans is planning to retain 8 inch stripes for HOV lanes. Going to 12-inch is not an option, as we already have many areas where they can barely comply with the 8-inch requirement. We may also look at the possibility of using 6-inch stripe. We are aware that none of these proposals meet MUTCD standards and will need to address that.
Quote from: jrouse on September 11, 2017, 12:20:46 AM
Quote from: roadfro on August 30, 2017, 10:54:28 PM
Quote from: joshI5 on August 30, 2017, 07:25:53 PM
I wonder what this will mean for HOV/HOT lane markings, when access is permitted. Doesn't the MUTCD require/recommend that preferential lane markings be double the width than those of normal lane markings? If so, I wonder whether Caltrans will widen the typical 8-inch wide stripe to a hearty 12 inches, or if they will employ a new design in adjustment to this update.
MUTCD Sec. 3A-06, standard: A normal line is 4-6 inches wide. A wide line is at least twice the width of a normal line.
MUTCD Sec. 3D-02, standard: For buffer-separated and contiguous preferential lanes, the dividing lane line(s) are to be wide white lines.
As of right now, Caltrans is planning to retain 8 inch stripes for HOV lanes. Going to 12-inch is not an option, as we already have many areas where they can barely comply with the 8-inch requirement. We may also look at the possibility of using 6-inch stripe. We are aware that none of these proposals meet MUTCD standards and will need to address that.
An update:
We will continue to use 8-inch stripe. Our traffic engineering team is interpreting the MUTCD standard liberally and believes that 8-inch meets the requirements for wide stripes. We will not be using 6-inch double white stripes on HOV lanes as they don't meet the MUTCD requirement.
Quote from: roadfro on September 01, 2017, 10:37:03 AM
Quote from: myosh_tino on August 31, 2017, 11:43:21 AM
I guess the key words are "at least twice the width" meaning Caltrans can use 6-inch normal lines and 8-inch wide lines. Any ideas how wide the lines on the I-15 Express Lanes in Las Vegas are?
In the north, NDOT uses a wider width for normal lines on all freeways, which I believe is 6 inches. But I think the I-15 express lane lines are a bit wider (not around them enough to directly compare though), so I'd guess they use 8 inches.
I'm down in Vegas right now and recently drove on I-15. I was unaware in my original post that the section of I-15 between 215 and Sahara with the express lanes is currently using raised pavement markers and paint to mark normal lane lines. With this, it looked to me like the normal lane lines and the solid express lane lines were the same width, so I think the express lane lines are 6 inches (instead of the 8 inches I speculated previously).
Quote from: roadfro on September 17, 2017, 10:09:33 AM
I'm down in Vegas right now and recently drove on I-15. I was unaware in my original post that the section of I-15 between 215 and Sahara with the express lanes is currently using raised pavement markers and paint to mark normal lane lines. With this, it looked to me like the normal lane lines and the solid express lane lines were the same width, so I think the express lane lines are 6 inches (instead of the 8 inches I speculated previously).
Looking at this Google Maps Street View (https://goo.gl/maps/eGPiqU9KHk12) of I-15 in Las Vegas, it's clear to me that the painted lane lines are 6 inches wide as the Botts Dots remain entirely within the painted stripe. To me, the white wide lines to the right of the image are 12 inches wide (2 x the 6-inch lane lines) but the width of the express lane lines appear to be somewhere in between the 6-inch lane lines and the 12-inch wide lines.
Quote from: jrouse on September 15, 2017, 02:58:03 PM
Quote from: roadfro on August 30, 2017, 10:54:28 PM
MUTCD Sec. 3A-06, standard: A normal line is 4-6 inches wide. A wide line is at least twice the width of a normal line.
MUTCD Sec. 3D-02, standard: For buffer-separated and contiguous preferential lanes, the dividing lane line(s) are to be wide white lines.
An update:
We will continue to use 8-inch stripe. Our traffic engineering team is interpreting the MUTCD standard liberally and believes that 8-inch meets the requirements for wide stripes. We will not be using 6-inch double white stripes on HOV lanes as they don't meet the MUTCD requirement.
So...
IF a "normal" line is 4-6 inches wide *AND* a "wide" line is at least twice the width of a normal line,
THEN a "wide" line must be at least 8-12 inches wide (2 x normal line).
It's an interesting interpretation of the MUTCD for sure. :)
Quote from: myosh_tino on September 17, 2017, 09:52:17 PM
Quote from: jrouse on September 15, 2017, 02:58:03 PM
Quote from: roadfro on August 30, 2017, 10:54:28 PM
MUTCD Sec. 3A-06, standard: A normal line is 4-6 inches wide. A wide line is at least twice the width of a normal line.
MUTCD Sec. 3D-02, standard: For buffer-separated and contiguous preferential lanes, the dividing lane line(s) are to be wide white lines.
An update:
We will continue to use 8-inch stripe. Our traffic engineering team is interpreting the MUTCD standard liberally and believes that 8-inch meets the requirements for wide stripes. We will not be using 6-inch double white stripes on HOV lanes as they don't meet the MUTCD requirement.
So...
IF a "normal" line is 4-6 inches wide *AND* a "wide" line is at least twice the width of a normal line,
THEN a "wide" line must be at least 8-12 inches wide (2 x normal line).
It's an interesting interpretation of the MUTCD for sure. :)
There's nothing that says the wide line has to be twice the width of the normal stripe used on the same road :spin:
So from a liberal interpretation of the MUTCD guidelines (which I very loosely summarized above), the Caltrans interpretation works.
Apparently, the discontinued use of Botts Dots is limited to roadways under state-maintenance. Two major streets in my home town were recently repaved and in both cases, only Botts Dots were used for the lane lines. No other type of striping was used (thermoplastic or paint).
Also, a section of Lawrence Expressway between Saratoga Ave and Homestead Rd was repaved by the county and it looks like they will also be using Botts Dots to mark the lane lines.
Quote from: myosh_tino on November 14, 2017, 05:18:30 PMdiscontinued use of Botts Dots is limited to roadways under state-maintenance. Two major streets in my home town were recently repaved and in both cases, only Botts Dots were used for the lane lines.
Not to mention private traffic areas. A center with Home Depot I went to in the Inland Empire did ALL their non-parking space striping in botts dotts. Everything!
(https://i.imgur.com/nA6kGrV.jpg)
Even trying to write out the word STOP :-o
Nuts for me to see, since I grew up in snow country where no raised markers are ever used, except those temporary flappy ones when a street is freshly repaved and restriped.
Parts of I-80 in Solano county has removed Botts dots.
Quote from: roadfro on August 24, 2017, 01:31:40 AM
^ I'm curious... The article/interview says that California is one of only 4 states still using Botts Dots. I know Nevada is another. What are the other two states?
There are some municipalities around Dallas/Ft. Worth TX that use Bott's Dots on their surface streets, but I don't recall seeing any on their freeways/tollways: its usually the black/white striping on those highways.
Quote from: i-215 on November 14, 2017, 07:49:08 PM
Not to mention private traffic areas. A center with Home Depot I went to in the Inland Empire did ALL their non-parking space striping in botts dotts. Everything!
(https://i.imgur.com/nA6kGrV.jpg)
Even trying to write out the word STOP :-o
That's crazy. I would have thought using paint would have been far cheaper than using all those Botts Dots to draw the arrows and spell out the word "STOP". :-D
First off, my apologies for dragging up a 4+ month old thread but...
While I see the need for going to a wider 6-inch stripe on freeways, highways and other higher speed roads, I really don't see the point of using them on city streets in urban areas. Case in point, the city of Sunnyvale recently repaved a section of Hollenbeck Avenue, a 2-lane city street through a residential area that sees a fair amount of traffic, and the city laid down 6-inch wide double-yellow lines. The lines are closer together due to the added width and look ugly as &^%$!
My question to those living in states where they use 6-inch stripes on freeways, does that carry over to city streets as well?
Quote from: myosh_tino on August 06, 2018, 02:42:59 PM
My question to those living in states where they use 6-inch stripes on freeways, does that carry over to city streets as well?
In Nevada, I've only ever seen the wide stripes on freeways and some divided state highways. I don't think I've seen wide stripes on city- or county-maintained streets.
Quote from: roadfro on August 07, 2018, 09:40:32 AM
Quote from: myosh_tino on August 06, 2018, 02:42:59 PM
My question to those living in states where they use 6-inch stripes on freeways, does that carry over to city streets as well?
In Nevada, I've only ever seen the wide stripes on freeways and some divided state highways. I don't think I've seen wide stripes on city- or county-maintained streets.
That's what I thought. I was in Reno a few weeks ago and I don't recall seeing 6" lane or double-yellow lines on city streets granted I was pretty much confined to the "tri-properties" area with the exception of a jaunt down to the Atlantis.
Quote from: myosh_tino on August 06, 2018, 02:42:59 PM
The lines are closer together due to the added width and look ugly as &^%$!
Yeah, the spacing on the new double yellow lines does look really weird. The old 4 inch lines had a 3 inch gap, which created a gap that was 75% of the width of each line.
The new 6 inch lines have the same 3 inch gap. To keep the same proportion they should really be using a 4 or 4.5 inch gap.
The other ratio that doesn't really work is that between the 6 and 8 inch lines -- it's too subtle. The lines for an exit only lane look very similar to the 6 inch through lanes; it's only the difference in length that makes the exit only line look different.
I know that Caltrans is hesitant to 12 inch lines due to space constraints, but it seems like the "double width" lines should be maybe 10 inches or so to make them stand out.
Quote from: jeffe on August 08, 2018, 12:21:03 AM
Quote from: myosh_tino on August 06, 2018, 02:42:59 PM
The lines are closer together due to the added width and look ugly as &^%$!
Yeah, the spacing on the new double yellow lines does look really weird. The old 4 inch lines had a 3 inch gap, which created a gap that was 75% of the width of each line.
The new 6 inch lines have the same 3 inch gap. To keep the same proportion they should really be using a 4 or 4.5 inch gap.
In the Sunnyvale example I referenced earlier, it looks like they went 6-1-6, meaning 6-inch wide yellow lines with a 1 inch gap. :wow:
For some reason, Caltrans is re-striping concrete bridge surfaces on a different schedule from the adjoining asphalt roadway, so you get the situation like shown below where you can compare the new and old types of striping:
(https://i.imgur.com/0ykEzY2.jpg)
Late in 2018, the lane lines on US 101's Bayshore Freeway segment in San Francisco were repainted to the 6-inch widths. Actually fascinating to see how the lane lines shrink once one reaches Brisbane going southbound!
Quote from: MarkF on January 24, 2019, 01:16:33 AM
For some reason, Caltrans is re-striping concrete bridge surfaces on a different schedule from the adjoining asphalt roadway, so you get the situation like shown below where you can compare the new and old types of striping:
(https://i.imgur.com/0ykEzY2.jpg)
Thermoplastic doesn't really hold up well on concrete from what I recall. Kentucky would apply thermoplastic on asphalt but not on the bridges, so they would be striped with regular paint trucks.
It seems that in addition to Caltrans some CA cities are doing away with raised reflectors -- or more likely, just not replacing them when the adhesive goes and the reflectors simply are tossed aside by traffic. Noticed that during the most recent severe storms last week; had to make a quick surface-street trip from SJ to Cupertino during the peak of the storm to replace a defective component for a client; most of the reflectors on the streets I used (Prospect, De Anza Blvd.) were gone -- made it very difficult to see the lane markings in sheeting rain. Now I'm wondering if local jurisdictions are planning on employing reflective thermoplastic lane markings to replace the raised markers a la Caltrans' new format; standard paint just doesn't cut it in severely foul weather. Either that -- or just retain the reflective markers, replacing them as needed!
Quote from: TheStranger on January 24, 2019, 02:08:42 PM
Late in 2018, the lane lines on US 101's Bayshore Freeway segment in San Francisco were repainted to the 6-inch widths. Actually fascinating to see how the lane lines shrink once one reaches Brisbane going southbound!
Update to my post:
Noticed the lane lines continue into South San Francisco. I'll have to look and see how far south they go in San Mateo County
From what I've seen, Caltrans is still using a single raised reflector between the new lines.
reflector, black line (if on concrete), white line, space (repeat)
Perhaps connected to this project: Driving I-15 from Barstow to Las Vegas today, I noticed that the "truck lanes" are now marked with standard dashed lane lines, not the solid white lines that have been used for years and years. There are still big overhead white signs that say "Truck lane / Slow vehicles only," but the pavement markings are just the usual. (In fact, you can see where the old solid line has been blasted away.)
Sorry, no pics.