Vegas area pavement and markers. Why?

[UptownRoadGeek]

Hey, Just wondering if someone here familiar with the southern area of NV could answer a few questions I had or provide some insight.

I'm accustomed to seeing Botts dots used in conjunction with stripping striping, but a total absence of stepping striping in most applications was a new one for me. Why is this?

Crosswalks, arrows, and any other pavement markings are all covered or appear to be dyed with a blackish /grayish tinge or tint. Why is this?

Is this only found in the Vegas area or is it more of a state/regional thing?

Many thanks to anyone who can answer.

[roadfro]

I'm accustomed to seeing Botts dots used in conjunction with stripping...

Funny, I've never seen Botts Dots at a strip joint... 

I'm accustomed to seeing Botts dots used in conjunction with stripping, but a total absence of stepping in many applications was a new one. Why is this?

Crosswalks, arrows, and any other pavement markings are all covered or dyed with a blackish /grayish tinge or tint. Why is this?

Nevada does not use pavement striping with raised pavement markers. I don't know why.


I'm not certain what you're referring to with the blackish tinge, but it's probably just roadway grime. The Vegas area only averages 4" of rainfall per year, so grime and other dirty elements have a tendency to stay on roads for a while. When the area does get a heavy rain, it tends to bring up those oils and make the roads a little more slick, and collisions tend to increase briefly as a result.

[UptownRoadGeek]

Funny, I've never seen Botts Dots at a strip joint... 

Ha, good catch.

Nevada does not use pavement striping with raised pavement markers. I don't know why.


I'm not certain what you're referring to with the blackish tinge, but it's probably just roadway grime. The Vegas area only averages 4" of rainfall per year, so grime and other dirty elements have a tendency to stay on roads for a while. When the area does get a heavy rain, it tends to bring up those oils and make the roads a little more slick, and collisions tend to increase briefly as a result.

Thanks for responding. Is the use of raised pavement markers alone a state practice or is it local to the Vegas area?

This is an example of what I was referreing to when I mentioned the crosswalks, etc. The pavement markers in Vegas just look they have a few layers of oil and grime over them, that I never see anywhere else. It's very consistent to where a lot of the markings appear to be gray instead of even a dirty reflective white.
Las Vegas Blvd @ Russell Rd
vs
W Pico Blvd @ S Western Ave

I was starting to wonder if it was a byproduct of the asphalt mixture used in the area as I noticed that driveways and parking lots with concrete pavement literally had significant staining from the adjacent asphalt.
Thanks for responding.

[sparker]

Caltrans has concluded that there are newer retroflective methods (adhesive striping, etc.) that have less downside (primarily maintenance) to them than the raised Botts dots and their wedge-shaped cousins, so they are busy replacing the raised markers with the new stuff; this process will, statewide, likely require several years.  Nevada tends to follow suit in regards to Caltrans practice; in this instance they didn't utilize the raised markers to any extent -- the question as to whether that was due to expense or simple lack of need is now moot.  Ironically, since it was announced that the raised dots were being phased out, there have been some objections to the change from the safety side -- the dots were certainly helpful in delineating lanes simply by the noise made from tires wandering over them (particularly in regard to drowsy drivers!). 

[UptownRoadGeek]

Ironically, since it was announced that the raised dots were being phased out, there have been some objections to the change from the safety side -- the dots were certainly helpful in delineating lanes simply by the noise made from tires wandering over them (particularly in regard to drowsy drivers!). 

Louisiana tackles this problem by attaching a row of 4 stimsonite reflectors to the end of each lane dividing stripe or placing the 4 reflectors in between each stripes. The only problem is that most of them have to be replaced every 2 or so years. Outside of rural areas it's reduced down to two stripes. It gives a tactile response to lane changes and illuminates the stripes at night or in rain. It's only done in freeways, however.

[roadfro]

Is the use of raised pavement markers alone a state practice or is it local to the Vegas area?

The practice is really only used by agencies in the Las Vegas area and in some parts of Clark County south of the Las Vegas area. It is mainly because other parts of the state are in areas that are more prone to receiving snow (so they're not used due to snow plows) or are in less traveled areas.

Perhaps an advantage to only using raised markers is less maintenance costs. Due to the propensity for road grime, the dots don't need reprinting every year, just new reflector markers every couple years.

This is an example of what I was referreing to when I mentioned the crosswalks, etc. The pavement markers in Vegas just look they have a few layers of oil and grime over them, that I never see anywhere else. It's very consistent to where a lot of the markings appear to be gray instead of even a dirty reflective white.
<...>
I was starting to wonder if it was a byproduct of the asphalt mixture used in the area as I noticed that driveways and parking lots with concrete pavement literally had significant staining from the adjacent asphalt.

Yeah, that is a product of road oils and grime. Driveways have the similar issue of tracking that, and not getting rain frequently to wash it away.