Caltrans: Botts Dots Out, 6-inch Lane Lines In

[jeffe]

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

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

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.   

[myosh_tino]

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.

[Max Rockatansky]

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.

[myosh_tino]

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.

[Max Rockatansky]

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. 

[jeffe]

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.


Fixed link. —Roadfro

[andy3175]

An article on this appeared in Mr. Roadshow:

http://www.mercurynews.com/2017/08/23/caltrans-says-bye-bye-to-botts-dots/

To 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.

[roadfro]

^ 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?

[mgk920]

^ 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

[jeffe]

^ 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.

[Tarkus]

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.

[bing101]

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.

[myosh_tino]

An article on this appeared in Mr. Roadshow:

http://www.mercurynews.com/2017/08/23/caltrans-says-bye-bye-to-botts-dots/

To 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.

[i-215]

^ 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.

[compdude787]

^ 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.

[bing101]

US-50 in Sacramento has no Botts Dots as of August 2017.

[joshI5]

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.

[roadfro]

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.

[myosh_tino]

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!

[roadfro]

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.

[AndyMax25]

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.

[jrouse]

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.

[jrouse]

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.

[roadfro]

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).

[myosh_tino]

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 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.