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Permanent freeway shooflies

Started by pderocco, September 22, 2024, 10:02:04 PM

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Bobby5280

We have one on I-44 between the Gore Blvd and Cache Road exits. ODOT poured a concrete slab in the median and had the "X" thing working for awhile when they were rehabbing the Cache Rd/I-44/2nd Street interchange. They never tore out the concrete when they were finished. They just installed some cable barriers to prevent vehicles from crossing over.

I-44 has a few other spots like that elsewhere in Oklahoma where they can remove the cable or concrete barriers and shift the directions of traffic.


pderocco

Quote from: Bitmapped on September 24, 2024, 06:59:25 PMOhio and Pennsylvania build them pretty frequently when doing bridge or roadway reconstruction. It allows them to close one side of the roadway to work on, or to cross one lane over to allow for a 2+1 / 1 configuration to maintain capacity through work zones. In these states, they're almost always removed when the project is completed.
Yeah, that's what they do here in California, too. But the idea of building them into the road at regular intervals seems like a good idea.

dantheman

Quote from: -- US 175 -- on September 24, 2024, 10:53:25 AMOther than the occasional work on a divided 4-lane (which would be more temporary) where drivers have to squeeze to just 2 of the lanes during construction of one set of lanes or the other, the only time I've seen this is on the HOV lane east of downtown on I-30 in Dallas. When WB drivers during morning rush hour come upon the east HOV entrance, there is an opening in the median barrier to veer left into.  Then drivers have to cross over to the EB side, where a zipper truck has moved the portable barrier over so that WB HOV traffic can use the lane and go into downtown.  Drivers will then reverse the process at the west end of the HOV lane.  They can get back on an I-30 main lane or exit at Cesar Chavez Blvd. for side-street travel into downtown.  This process is reversed during afternoon rush hour where EB I-30 traffic (and those getting on I-30 from Cesar Chavez) get over to the left WB lane.

I'm not sure why they do the HOV this way instead of same-direction traffic on the same side, other than not wanting to take out any lanes needed during rush hour.  I'm not sure if the upcoming I-30 work to redo this particular part of the freeway (the work will take at and above-ground lanes and trench them) will take a different approach to HOV/managed lanes or what, but surely the crossings and zippering will go away after the redo is completed.

If I'm understanding this right, something pretty similar is done on the Southeast Expressway (I-93) between downtown Boston and the MA 3 junction. To implement an HOV lane without widening the highway, the setup is this:
- Normal operations: 4 lanes NB, 4 lanes SB, two "zipper" barriers in the middle with no traffic between them
- AM rush hour: 4 regular lanes NB, one of the zipper barriers is moved over to form a NB HOV lane in what's usually the SB fast lane, and three remaining SB lanes
- PM rush hour: 3 lanes NB, the other zipper is moved over to turn the NB fast lane into a SB HOV lane, and then the regular 4 lanes SB

As luck would have it, the Google Street View driver drove NB during the PM rush hour (poor sucker) while this setup was being used. The bus in this picture is in the SB HOV lane, which is normally the left lane NB:
https://maps.app.goo.gl/hN1qwemkQ7toVZ9s7

At least at the southern end of this setup, the HOV entrance is signed for something like 35 mph due to the sharp curve to get across the median. Normally this would be awfully slow for a left exit, but since the highway is usually crawling at about 10 mph during rush hour anyway, it's not so bad!

SSR_317

Quote from: Bitmapped on September 24, 2024, 06:59:25 PMOhio and Pennsylvania build them pretty frequently when doing bridge or roadway reconstruction. It allows them to close one side of the roadway to work on, or to cross one lane over to allow for a 2+1 / 1 configuration to maintain capacity through work zones. In these states, they're almost always removed when the project is completed.
That's what usually happens here in Indiana as well. Once the project necessitating the crossover is completed, the "X" lanes are permanently removed and the median regraded (for drainage) and reseeded with grass (in most cases).

Quillz

Quote from: cl94 on September 24, 2024, 01:17:28 AMIn the case of CA ag inspection stations, the road without the ag station typically still exists, but you're usually kicked off into the ag inspection detour.
I had at least one time the inspection station was closed and we just kept going down the main road, so I assume that's why they are designed as they are.



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