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#91

Southeast / Re: I-40 in North Carolina

Last post by jdunlop - April 24, 2024, 08:38:20 PM

The design year traffic volume is at least 20 years from the time construction is planned to start. The design year is 2040 for this project, which is now the estimated let date. The problem is the final planning document was signed by the FHWA in 2018. Things kind of get etched into stone at that point. The final design plans can't deviate very much from what was complete when the planning document was signed without starting the planning and review process all over again. Design and planning is expensive and lead to further delays. An updated traffic forecast may still happen, but unless the forecast shows the proposed design won't operate at an acceptable level of service in the new design year, the design is unlikely to change. So, unless there are drastic changes to the land use in the area and/or significant increases in traffic volumes, the design probably won't change at this point. Traffic counts at the interchange from the past several years don't really reflect that, but the latest counts are from 2022.

I can think of several other projects off hand that have traffic forecasts that are many years old with no sign of construction starting within the next decade and have wondered if they will remain unchanged or not.

I still don't know why a SPUI wasn't considered for this location and why NCDOT doesn't build them now. They specifically cited the right-of-way limitations at this interchange as a reason for not going with a different design than what was selected. It's been several years (decade?) since a SPUI was constructed in North Carolina, and I only know of one that is still proposed at Glenwood Ave./Brier Creek Pkwy. in Raleigh. Yeah, they're expensive, but it seems like these types of locations would warrant the compact design and associated cost.

Note that the listed let date of 2040 is a placeholder at this time, although there's some projects that will take that long through the prioritization process.

FHWA does require traffic forecasts to be within 20 years of project let. IF within a couple of years, the Roadway Design team often would just take the growth rate and project a few years more.  Future volumes are updated for each new round of prioritization, although the volumes used are not the traditional full traffic forecast, but an estimate based on current AADTs, traffic counts (primarily for turning movement percentages) and historic growth rates.  The latter is usually sufficient for most projects, including the interchange in Morgantown.  (The SPOT process does review locations for anything that has changed in the area, which would drive the need for a full traffic forecast if those changes aren't covered adequately by the recent traffic counts.)

SPUIs went out of fashion once the DDI came in.  The DDI is usually as efficient, and far less costly.  I basically killed the SPUI in NC after the first DDI was opened in 2009.  Changed at least three projects and saved a lot of money - I-95 exit 22 in Lumberton, Catawba Ave on I-77 in Cornelius and Union Cross Road at I-40 in Winston-Salem.  Probably a few others, but not remembering them right now.  (The SPUI could not reasonably be built in Lumberton due to the angle of the road crossing, IIRC the differences between the SPUI and DDI were about $20M for Cornelius back in 2009, and I know we saved at least $10M at Union Cross, a great deal by not needing to tear down a less than 20 year bridge but building a new one next to it.)

Very few locations would warrant a SPUI these days, the US 70/Brier Creek location is one of those few.  The location in Morganton is not.  The volumes can be easily handled with a DDI or tight diamond (which, if I read the preliminary plans correctly, put the ramps about where they are now, with the new bridge shifted a bit to the west for construction while under traffic.)

To ARMOURERERIC, loops aren't always for the highest volume of ramp traffic.  It used to be that Roadway Design would leave space for ramps in quadrants A & C (on-ramps to the freeway.)  Usually called a parclo A (partial cloverleaf in the A and C quadrants.)  We came to an aha moment about 10 years ago, realizing that the problem with Parclo A is that there are two on-ramps, creating more conflict points, with the loop ramp acceleration shortened by the other on-ramp.  Plus, the ramp intersections on the surface street required the ramp traffic phase to stop both directions of traffic. The Parclo B removes the dual on-ramp issue, and on the surface street the ramp intersections are leftovers, very similar to RCUTs/Superstreets/RCIs, with the same efficiency.  Hard for a designer to change a long history of design, but they're many of the same ones that continued to insist on five-lane roads (instead of medians) long after they were shown to be significantly less safe.  (Of course, like me, many are now retired!)

(There are always locations that are exceptions, such as the SPUI at Brier Creek.)

#92

Northeast / Re: New York

Last post by webny99 - April 24, 2024, 08:37:00 PM

Psst.  That's because CCs are becoming obsolete with modern data collection methods...

What modern data collection methods would replace CC's?

#93

Great Lakes and Ohio Valley / Re: Update on I-69 Extension i...

Last post by ilpt4u - April 24, 2024, 08:29:49 PM

Would AASHTO or FHWA consider not giving final approval to sign the final segment of 69 being constructed now and also not along 465 until the mileage is fixed?

I mean, FHWA did lay out a list of things, that includes standardized mile markers and exit numbers for both INDOT and KYTC, before I-265 can be signed between I-65/IN and I-71 aka the "East End Crossing" which is still not complete, despite the bridge/route linking the previously physically disconnected I-265s being open since late 2016!

[Schor sees neighborhood improvement where some westsiders see a step back]

#94

Great Lakes and Ohio Valley / Re: Michigan Notes

Last post by JREwing78 - April 24, 2024, 08:27:44 PM

More info from City Pulse about the proposed MLK Blvd conversion in Lansing:

Schor sees neighborhood improvement where some westsiders see a step back from 03/1/2024
https://www.lansingcitypulse.com/stories/schor-leaning-toward-removing-the-islands-from-a-stretch-of-mlk-jr-boulevard-despite-neighborhood,88405?

'How to not involve the community' Letter to the editor from 3/7/2024
https://www.lansingcitypulse.com/stories/letter-to-the-editor-how-to-not-involve-the-community,88933?

City offers a new choice for MLK Boulevard changes after vocal opposition
https://www.lansingcitypulse.com/stories/city-offers-a-new-choice-for-mlk-boulevard-changes-after-vocal-opposition,93046?

Reddit discussion is basically calling the residents who are against the change uninformed Boomers, though said Reddit discussion also seemed in the dark about what the city was actually doing.

I doubt, for instance, that anyone in the neighborhood objected to fewer lanes and a bike lane/path. They're objecting to further changes that push the traffic up against the neighborhood and move all the greenspace towards downtown, further isolating the neighborhood. I happen to agree with that sentiment, particularly if they're replacing median with a 5-lane roadway that's harder for pedestrians to cross. 

Once again, Boomer NIMBYs impeede progress: Construction on Lansing's Martin Luther King Jr. Boulevard is to be paused - listed here as posted
https://www.reddit.com/r/lansing/comments/1cbxduh/once_again_boomer_nimbys_impeede_progress/

#95

Great Lakes and Ohio Valley / Re: Illinois: Round Mile Mark...

Last post by ilpt4u - April 24, 2024, 08:20:47 PM

IL-919 by Paul Across America, on Flickr

That is Old US 51 south of Carbondale, down to Makanda and the Union County line

Old 51's designation on the reference marker changes when one crosses the Jackson/Union County line between Makanda and Cobden, fwiw. 919 in Jackson and 911 in Union

#96

Traffic Control / Re: Unique, Odd, or Interestin...

Last post by 74/171FAN - April 24, 2024, 08:19:53 PM

On US 70 WB in Conover, NC. (https://www.facebook.com/photo/?fbid=10220246086582844&set=a.10220246332869001)

#97

Traffic Control / Re: Is Georgia finally getting...

Last post by Tom958 - April 24, 2024, 08:17:30 PM

Probably not news for this thread, but just saw this example: https://maps.app.goo.gl/LCsTy9GpFFsLGyvA9
So they opted for "two through destination arrows" for 285S and 85N

How serendipitous. I won't have to post a "before" link-- you already did.

I'd forgotten about this thread, but in mid-March, the above assembly was changed to this monstrosity. As well as replacing the conventional sign for the Buford Highway exit with that APL-themed freak, they removed the split arrow and the curved arrow from the APL, thereby removing the rationale for even having an APL. So much for GDOT getting it.

Trying to make some sense of this: the Buford Highway exit has a fairly long decel lane, and I guess that after all these years someone decided it was long enough to rate EXIT ONLY signage. But they could've used conventional signage like this instead of copying something dumb that Alabama did. As for removing the essential features of what had been an MUTCD-compliant APL, I can't imagine what they were thinking.

#98

Pacific Southwest / Re: CA 203

Last post by Max Rockatansky - April 24, 2024, 08:14:02 PM

I believe both were intended to be freeway/expressway all the way to the crest of the Sierra Nevada range.  Stuff like the freeway alignment which was intended to replace the Priest Grade were wild to read about in the CHPWs.

Have a link or photos of the Priest Grade plans? I figured that was what they were going for by the half completed Don
Pedro Reservoir overpass on 120.

Photo 28:

https://www.gribblenation.org/2022/07/california-state-route-120new-priest.html?m=1

#99

Mountain West / Re: US 50 Bridge Failure Betwe...

Last post by thenetwork - April 24, 2024, 08:08:03 PM

Still no timetable on when the bridge "could" open.

https://www.kjct8.com/2024/04/24/highway-50-bridge-closure-meeting-recap/?fbclid=IwZXh0bgNhZW0CMTEAAR1qbqptYzX3KrEaE6JPHkIug-aPl5T-K0BDrPgE7upkDvZR2Y5SdiEhJ_I_aem_AaaUU5Azc69OHa758frOmP9igpZmDARZC0RCzJ7V52gvYoftyb2QQK4GnxlncofIsmL9SF53UU2G_TeQcSKBuegf

#100

Great Lakes and Ohio Valley / Re: Update on I-69 Extension i...

Last post by tdindy88 - April 24, 2024, 07:48:50 PM

I did a interesting exercise in the routing of I-69 through Indianapolis. If I-69 was routed along I-465 from Exit 5 east to Exit 53 (the south side I-65 interchange) and then multiplexed with I-65 north through the city and all the way to Exit 123 and then routed along I-465 across the northwest and north sides to Exit 37, it would be roughly a 38-39 mile routing. That would fill the gap between mile markers 163 and 200 a lot better. Not perfect but a lot closer. Not that any of this would happen of course, it would be a ridiculous routing. But if we were to be pedantic let's do it with some style!

As much as I'd like to see them update the mileage on the northern part of I-69, I can live with it remaining as it is. Few Hoosiers probably truly care exactly about this sort of thing.