Are there any new highways being built with a concrete median?

[MikieTimT]

I don't think it's the barrier/jersey type median the original poster is looking for, but technicallyof Longmeadow Parkway from around IL 31 to just east of the Fox River crossing in the Chicago suburbs has a concrete median.

Doesn't most of the Missouri portion of the Bella Vista Bypass on I-49 have a concrete barrier median?

The entirety of the Bella Vista Bypass in Missouri is on narrow ROW with a concrete median, except the ends where it splits to divided to cross the Arkansas border and at the entrance and exit ramps to the old endpoint at the north end where it dumped onto US-71.  All of the 6-8 laned portions of I-49 in NWA now have concrete barrier median as the old grass median was excavated for drainage conduit, then filled and paved over with a concrete barrier on top.

[Rick Powell]

Here's another one in IL. IL 255 from I-270 to Godfrey in the metro St. Louis area, built in sections from 1998 to 2012. Most of it is grass median, but there is a stretch from north of Vaughn Road to the IL 111 interchange that has a median barrier. Maybe 10% of the total length.

[jakeroot]

In the Seattle area, both the WA-167 and WA-509 extensions are to be concrete median barriers.

[Crown Victoria]

If I recall correctly, the PTC has designed the pending Mon-Fayette Expressway section north of PA 51 on a narrow footprint with a concrete median, to help keep ROW costs down. Originally it was supposed to have a wider grass median.

Speaking of the PA Turnpike, the mainline also was originally built with a grass median. The median was paved over and Jersey barriers were added some time later.

[jeffandnicole]

If I recall correctly, the PTC has designed the pending Mon-Fayette Expressway section north of PA 51 on a narrow footprint with a concrete median, to help keep ROW costs down. Originally it was supposed to have a wider grass median.

Speaking of the PA Turnpike, the mainline also was originally built with a grass median. The median was paved over and Jersey barriers were added some time later.

And I think the jersey barriers are a 3rd generation barrier.  The first was a simple guardrail.  Then they used some sort of odd convex-shaped contraption device that was probably some politician's son's 5th grade science project invention that, after installing it on a few hundred miles of roadway where it was constantly beat up with pieces breaking and flaking all over the place, made them realize why they shouldn't use some politician's son's 5th grade science project invention.  Then came the oversized but otherwise standard jersey barrier.

[Scott5114]

A Wikipedia list is also subject to the selection bias of a Wikipedia editor hearing of it and giving enough of a shit to put it on the list. The number of lists that have a patron contributor checking the news every day for a new item to add to them is very low.

Eh, in the long run it should settle out close enough.

Anyone aware of any 100+ car accidents not on the list?

"Should" doesn't necessarily mean "will". I generally believe in the Wikipedia process–hell, I have admin rights there too–but it does have its shortcomings, and completeness of lists like this is one of them.

How would one even prove whether a list like this is 100% complete?

[jmacswimmer]

some sort of odd convex-shaped contraption device that was probably some politician's son's 5th grade science project invention

Are you referring to this?  (From I-83 just north of the MD/PA line, where a short stretch of the stuff still exists.)

[jeffandnicole]

some sort of odd convex-shaped contraption device that was probably some politician's son's 5th grade science project invention

Are you referring to this?  (From I-83 just north of the MD/PA line, where a short stretch of the stuff still exists.)

Yes, exactly!

[rower155]

↑ Selection bias: a multi-vehicle pileup is more likely to happen near barriers because roads with higher traffic volumes tend to have barriers. Urban highways are also more likely to have barriers, and a pileup in an urban area is more likely to get significant media coverage than one in a rural area (which is less likely to have barriers).

This isn't entirely correct.  AASHTO RDG is a good source, "It is important to note that the probability or frequency of run-off-the-road crashes is not directly related to the severity of potential crashes."

Related to the OP, the point here is that barrier itself is a hazard. It is generally used judiciously when designing a new highway.  The RDG further supports this, "The mere installation of barriers could lead to higher incident rates due to the proximity of the barriers to the traveled way."

[HighwayStar]

A Wikipedia list is also subject to the selection bias of a Wikipedia editor hearing of it and giving enough of a shit to put it on the list. The number of lists that have a patron contributor checking the news every day for a new item to add to them is very low.

Eh, in the long run it should settle out close enough.

Anyone aware of any 100+ car accidents not on the list?

"Should" doesn't necessarily mean "will". I generally believe in the Wikipedia process–hell, I have admin rights there too–but it does have its shortcomings, and completeness of lists like this is one of them.

How would one even prove whether a list like this is 100% complete?

I don't think its necessary to prove it complete, but if it is that incomplete it should be easy to point out a few omissions.