I-44's Extension into Texas via the substandard H.E. Bailey Turnpike

[Beltway]

On cable barriers, I once worked for a guy who sung their praises and yes, when properly installed and maintained they are quite strong and perform well...
...BUT, if they get hit once, you have to re-tension the entire system (which my former boss admitted).  So, despite the pros, that's why their implementation has been diminishing or restricted to certain situations.

Tension zones are in the 1,000 to 2,000 foot long range on high-tension cable guardrail. Anchor footers are used to tie a segment terminus to the ground. That would be the only part needing to be retensioned.

Eh, that just supports my point given how much easier box beam is to replace, in particular.

Same with W-beam, comes in 25 foot sections. But on high-tension cable guardrail they don't "re-tension the entire system."

[Rothman]

On cable barriers, I once worked for a guy who sung their praises and yes, when properly installed and maintained they are quite strong and perform well...
...BUT, if they get hit once, you have to re-tension the entire system (which my former boss admitted).  So, despite the pros, that's why their implementation has been diminishing or restricted to certain situations.

Tension zones are in the 1,000 to 2,000 foot long range on high-tension cable guardrail. Anchor footers are used to tie a segment terminus to the ground. That would be the only part needing to be retensioned.

Eh, that just supports my point given how much easier box beam is to replace, in particular.

Same with W-beam, comes in 25 foot sections. But on high-tension cable guardrail they don't "re-tension the entire system."

25' < 1,000'

[kphoger]

No, no, it has to be re-tensioned all the way to Joplin.  Doesn't matter what highway it's on.

[Beltway]

Same with W-beam, comes in 25 foot sections. But on high-tension cable guardrail they don't "re-tension the entire system."

25' < 1,000'

A large truck can destroy 200 feet of W-beam guardrail. And it is less effective than high-tension cable guardrail.

[Rothman]

Same with W-beam, comes in 25 foot sections. But on high-tension cable guardrail they don't "re-tension the entire system."

25' < 1,000'

A large truck can destroy 200 feet of W-beam guardrail. And it is less effective than high-tension cable guardrail.

200' < 1,000' and still easier to replace than cable...

[Beltway]

Same with W-beam, comes in 25 foot sections. But on high-tension cable guardrail they don't "re-tension the entire system."

25' < 1,000'

A large truck can destroy 200 feet of W-beam guardrail. And it is less effective than high-tension cable guardrail.

200' < 1,000' and still easier to replace than cable...

Not necessarily. The cables are generally reusable and the weak posts are less expensive than the strong posts.

With W-beam the whole stretch needs to be replaced -- posts, blockouts and beams. More labor needed as well.

[Rothman]

Same with W-beam, comes in 25 foot sections. But on high-tension cable guardrail they don't "re-tension the entire system."

25' < 1,000'

A large truck can destroy 200 feet of W-beam guardrail. And it is less effective than high-tension cable guardrail.

200' < 1,000' and still easier to replace than cable...

Not necessarily. The cables are generally reusable and the weak posts are less expensive than the strong posts.

With W-beam the whole stretch needs to be replaced -- posts, blockouts and beams. More labor needed as well.

All I can say to that is the cost analysis of which guiderail type to use has been done by DOTs and it refutes this off-the-cuff idea of yours.

[PColumbus73]

Question: If re-tensioning cable barriers is too cumbersome, has there been any study about layering guardrails? So, have an inner layer at the centerline of the median and an outer layer between the edge of pavement and the inner layer?

[Beltway]

Same with W-beam, comes in 25 foot sections. But on high-tension cable guardrail they don't "re-tension the entire system."

25' < 1,000'

A large truck can destroy 200 feet of W-beam guardrail. And it is less effective than high-tension cable guardrail.

200' < 1,000' and still easier to replace than cable...

Not necessarily. The cables are generally reusable and the weak posts are less expensive than the strong posts.  With W-beam the whole stretch needs to be replaced -- posts, blockouts and beams. More labor needed as well.

All I can say to that is the cost analysis of which guiderail type to use has been done by DOTs and it refutes this off-the-cuff idea of yours.

So where are these cost analyses that you are referring to?

You know that it varies widely depending on 1) AADT, 2) median width, and 3) barrier type.

[Scott5114]

So where are these cost analyses that you are referring to?

Albany, I'd imagine.

[Rothman]

Question: If re-tensioning cable barriers is too cumbersome, has there been any study about layering guardrails? So, have an inner layer at the centerline of the median and an outer layer between the edge of pavement and the inner layer?

What's the need for this, though?

[PColumbus73]

Question: If re-tensioning cable barriers is too cumbersome, has there been any study about layering guardrails? So, have an inner layer at the centerline of the median and an outer layer between the edge of pavement and the inner layer?

What's the need for this, though?

If re-tensioning cable barriers is less cost effective than a standard guardrail, but have better crash absorption than a guardrail, would layering guardrails fill the void between maintenance cost and crash absorption?

[Rothman]

Question: If re-tensioning cable barriers is too cumbersome, has there been any study about layering guardrails? So, have an inner layer at the centerline of the median and an outer layer between the edge of pavement and the inner layer?

What's the need for this, though?

If re-tensioning cable barriers is less cost effective than a standard guardrail, but have better crash absorption than a guardrail, would layering guardrails fill the void between maintenance cost and crash absorption?

Do we need better crash absorption than what box beam or other standard guiderail currently provides? 

[kphoger]

A large truck can destroy 200 feet of W-beam guardrail. And it is less effective than high-tension cable guardrail.

Do we need better crash absorption than what box beam or other standard guiderail currently provides? 

Maybe?

[kphoger]

guiderail

Also:  stop that.  Stop pretending that's a word.  I don't care if you are from New York.

[74/171FAN]

guiderail

Also:  stop that.  Stop pretending that's a word.  I don't care if you are from New York.

PA uses it too.  Apparently a court case forces us to.

[Beltway]

guiderail

Also:  stop that.  Stop pretending that's a word.  I don't care if you are from New York.

PA uses it too.  Apparently a court case forces us to.

PennDOT mainly called it guard fence in the 1970s and before.

[Rothman]

A large truck can destroy 200 feet of W-beam guardrail. And it is less effective than high-tension cable guardrail.

Do we need better crash absorption than what box beam or other standard guiderail currently provides? 

Maybe?

I'm not hearing a lot of clamoring for it.  Closest there was to that was a road meet attendee that told me all work zones should have temporary concrete barrier (which would be a huge expense...but it may save lives...despite the fact that reckless or under the influence drivers still find a way to kill people behind TCB...).

[bwana39]

Same with W-beam, comes in 25 foot sections. But on high-tension cable guardrail they don't "re-tension the entire system."

25' < 1,000'

A large truck can destroy 200 feet of W-beam guardrail. And it is less effective than high-tension cable guardrail.

And one might argue that continuous jersey barrier is more effective than that....

[rte66man]

I got my 1971 Texas/Oklahoma AAA map that was with me on that 1971 trip. This shows it all freeway between I-35 in OKC and the Wichita Falls small freeway system (US-287 east-west and US-277 north-south).

In 1971, there was still an at-grade intersection in Lawton, plus the couple of at-grade intersections in Texas that I already mentioned.  At least.  So, if your AAA map shows it as having been full freeway at that time, then they were overly optimistic.

I do recall a toll-free section at Lawton and one at Chickasha.

The Lawton area is still a free portion.  However, I don't think the same is true of Chickasha.

There has never been a free section in Chickasha. When the Bailey opened in 1964, there was only a half-diamond at US62 (entry NB and exit SB).

[kphoger]

How about two cable barriers? 

https://maps.app.goo.gl/MzHdx2xsFjNRYMLA7

[Bobby5280]

That double cable barrier thing is kind of similar to this short segment in Lawton:
https://www.google.com/maps/@34.6140795,-98.380256,3a,75y,184.2h,79.6t/data=!3m7!1e1!3m5!1s31Z3tQQb8ow-YJB0tcVx0g!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D10.404571383823097%26panoid%3D31Z3tQQb8ow-YJB0tcVx0g%26yaw%3D184.20334629662545!7i16384!8i8192?authuser=0&entry=ttu&g_ep=EgoyMDI2MDQyNi4wIKXMDSoASAFQAw%3D%3D

That paved spot was originally created as a crossover point for past road construction where one set of lanes would be shut down and opposing traffic shifted to one lane on the other side. The cable barriers were installed later. I have seen OHP and local police use that as a turn-around point. The cables barriers are staggered so a vehicle can pass between them.

[kphoger]

That paved spot was originally created as a crossover point for past road construction where one set of lanes would be shut down and opposing traffic shifted to one lane on the other side. The cable barriers were installed later.

Yes, it's similar with the I-35 example I posted, although the crossover was actually an interchange between the exit and head-to-head traffic while one half of the Interstate was closed.  Here's the same spot during the road construction project.

[Beltway]

How about two cable barriers? 
https://maps.app.goo.gl/MzHdx2xsFjNRYMLA7

Exactly. There are a variety of treatments.

Segment of I-64 between Covington and Clifton Forge, Virginia.
A 15 foot grass median treated with 2 runs of high-tension cable guardrail.

[The_Ginger]

Talk about a narrow median? Kanawha Boulevard in Charleston, W. Va. says hello.