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3 di's

Started by ethanhopkin14, July 27, 2020, 08:47:26 AM

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webny99

Quote from: thspfc on July 29, 2020, 11:38:35 AM
I have not read any replies yet ...

Not usually the greatest strategy, but we've all been guilty of doing that at some point.  :)


jmacswimmer

Quote from: Roadgeekteen on July 29, 2020, 04:05:49 PM
Should I-95 in DC be switched to the western side of the beltway?

I don't think so - I suspect the reason I-95 was put around the eastern side, despite being a few miles longer, is that the eastern side of the beltway passes thru less dense suburbs (relatively-speaking) than the western and northern sides do (which has to squeeze thru Tysons, Bethesda, and Silver Spring to name a few).  On the Maryland side of the beltway, it's quite noticeable that the PG County portion generally has milder curves and a wider ROW compared to the Montgomery County portion.  (The county line, for reference, happens to be a mile west of the I-95 interchange.)

Obviously the eastern side still has its issues too, but the decision-makers probably figured it was the lesser of 2 evils in terms of thru traffic.
"Now, what if da Bearss were to enter the Indianapolis 5-hunnert?"
"How would they compete?"
"Let's say they rode together in a big buss."
"Is Ditka driving?"
"Of course!"
"Then I like da Bear buss."
"DA BEARSSS BUSSSS"

sprjus4

Quote from: Roadgeekteen on July 29, 2020, 04:05:49 PM
Quote from: sprjus4 on July 29, 2020, 12:30:18 PM
Quote from: 1995hoo on July 29, 2020, 11:23:23 AM
I-475 passing Macon presents an unusual situation. It follows the conventional pattern of the 3di bypassing the city while the 2di (I-75) more directly serves the city itself, but what's unusual here is that the 3di covers a shorter distance for thru traffic than the 2di route does. More often a 3di loops around a city and covers a longer distance, but in Macon, you could visualize it as a bow and arrow situation where I-75 is the "bow" and I-475 is the "bowstring." I don't know off the top of my head whether this is truly "unique" in terms of there being no other place where that sort of thing happens, though, and I don't have time to look it up just now.
In the DC area, I-495 around the western side of the beltway is a shorter distance than following I-95 around the eastern side of the beltway.

In Hampton Roads, I-664 is a significantly shorter distance between Hampton and Bowers Hill as opposed to following I-64's arc around the eastern side of the metro.
Should I-95 in DC be switched to the western side of the beltway?
No real need to anymore.

sprjus4

#53
Quote from: jmacswimmer on July 29, 2020, 04:29:25 PM
Quote from: Roadgeekteen on July 29, 2020, 04:05:49 PM
Should I-95 in DC be switched to the western side of the beltway?

I don't think so - I suspect the reason I-95 was put around the eastern side, despite being a few miles longer, is that the eastern side of the beltway passes thru less dense suburbs (relatively-speaking) than the western and northern sides do (which has to squeeze thru Tysons, Bethesda, and Silver Spring to name a few).  On the Maryland side of the beltway, it's quite noticeable that the PG County portion generally has milder curves and a wider ROW compared to the Montgomery County portion.  (The county line, for reference, happens to be a mile west of the I-95 interchange.)

Obviously the eastern side still has its issues too, but the decision-makers probably figured it was the lesser of 2 evils in terms of thru traffic.
Anybody following a GPS would be routed along either the western beltway, or I-495 / I-95 then up the B.W. Parkway to Baltimore to rejoin I-95. At least with Google Maps... it's never recommended I-95 all the way.

Signage and the way VDOT reconfigured the Springfield Interchange to make the I-95 movement a thru, left-hand movement though, directs you to take I-95 all the way however.

As for the eastern beltway / I-95 portion, many segments can feel rural, and drivers treat it that way with traffic flow easily cruising at 75 - 80 mph even when heavier despite the artificial 55 mph speed limit. Considering they increased I-95 between Washington and Baltimore and US-50 / I-595 between I-495 / I-95 and Annapolis to 65 mph, I still don't understand why they refuse to increase I-95 / I-495 for most of its length, along with I-270 outside the Beltway, to 65 mph.

Is there really any difference in traffic flow speed on the 65 mph segment of I-95 outside the beltway vs. the 55 mph segment of I-495 / I-95 beltway? Raising it would likely not result in much changes with driver speed, but would bring the speed limit closer to reality.

thspfc

Quote from: webny99 on July 29, 2020, 04:08:42 PM
Quote from: thspfc on July 29, 2020, 11:38:35 AM
I have not read any replies yet ...

Not usually the greatest strategy, but we've all been guilty of doing that at some point.  :)
I didn't read the replies so that I could make guesses on the questions, instead of just looking at the answers.

SGwithADD

Quote from: webny99 on July 29, 2020, 11:28:32 AM
Quote from: ethanhopkin14 on July 29, 2020, 10:55:38 AM
I feel that any 3di that serves a downtown area while it's parent bypasses the city is unique.

Not the case here in Upstate NY. That happens in every major city: Buffalo (I-190), Rochester (I-490), Syracuse (I-690), Utica (I-790) and Albany (I-787).
2di's going through downtown are common in other parts of the country, but not here. It's either 3dis or no freeways at all.

It's also common in Pennsylvania:

  • Pittsburgh's is bypassed by all three nearby 2dis, with 3dis only in the city (I-376, I-279, I-579)
  • Philadelphia has I-76 go around South Philly while I-676 goes downtown
  • Reading is bypassed by I-76 and served by I-176
  • Scranton is bypassed by I-80, and served by I-380
  • Williamsport is bypassed by I-80, and served by I-180
  • In the past, before I-78 was rerouted off of US 22, it avoided the downtown areas of Allentown and Bethlehem, which were supposed to be served by 3dis (I-178 and I-378)

Bruce

How many 3dis are busier than their parents?

I-405 in WA gets fairly close, with 209K in Bellevue versus 274K in Seattle, and has an opposite design: plenty of throughput through the "downtown" and fewer lanes in the outer edges, unlike I-5's narrower portion being in downtown.

GaryV

In Flint and Saginaw, the 3di's go through town while I-75 is more of a bypass.  Especially Saginaw.

Rothman

Quote from: GaryV on July 29, 2020, 08:10:13 PM
In Flint and Saginaw, the 3di's go through town while I-75 is more of a bypass.  Especially Saginaw.
Makes me wonder about I-690 and I-90 in Syracuse, NY.
Please note: All comments here represent my own personal opinion and do not reflect the official position(s) of NYSDOT.

Big John

Quote from: Bruce on July 29, 2020, 08:02:43 PM
How many 3dis are busier than their parents?
I believe I-475 has more traffic than I-75 in Macon GA

kkt

Quote from: texaskdog on July 29, 2020, 12:27:39 PM
curious why they didn't go to 4 digits when they ran out of 3.  if they already had 9 x80s who not a 1080, 1180?  is it due to shield size?  or did they just not care.

My suspicion is a combination of shield size and easy recognition on signs, even in bad weather while traveling at freeway speeds.

I'd suggest picking an honorary 2di number that doesn't actually exist within the state and numbering additional 3dis off of that.  For example, if a 3di were wanted for the bypass loop around Sacramento rather than moving I-80 to the bypass route, it could be I-282.  Then the infamous I-238 could be I-382.  The I-80 Albany to San Rafael segment could be I-482 instead of an extension of I-580.

Also 4dis would be fine for hidden interstates, such as hidden I-305 over US 50 in Sacramento could instead be I-1305.


Road Hog

Quote from: ethanhopkin14 on July 29, 2020, 07:42:01 AM
Quote from: ilpt4u on July 29, 2020, 01:19:02 AM
Quote from: DJ Particle on July 29, 2020, 12:54:39 AM
Which begs anothr question...how many states have a mainline interstate which runs less miles in its state than its 3dis?  I trust I-80 in CA easily meets that criteria.  I'd also nominate I-95 in MA.

I assume that is supposed to be I-95 in MD, not MA? Guess it could be either. If unsigned I-595 in MD is counted, it probably helps the case (No, I haven't measured)

I would also suggest I-95 in DC, but DC isn't really a state

I-95 in NY should qualify, I would think. I-78 in NY really qualifies

Trying a bigger state, I thought I-35 might pull this off in Kansas. But it is 215 miles, and its 3dis in KS add up to ~155 miles. 60 miles isn't too big a number, tho

Quote from: DJ Particle on July 29, 2020, 12:54:39 AM
EDIT:  Also...are there any other situations where a 3di enters a state its parent doesn't?  All I can think of off the top of my head is I-535 in WI.
I-129 and Nebraska

I-275 and Indiana

At present, one might argue I-269 around Memphis. I don't think I-69 is signed yet officially in TN

Honorable mention:

I-155 going from Arkansas to Tennessee.  Although I-55 obviously goes through Tennessee, going south to north, I-55 has long entered and exited the state by the time I-155 enters the state, so it almost qualifies.  Also, I-55 is longer in Tennessee, 15 miles over I-55's 12.

I-155 starts in the Missouri Bootheel, not in Arkansas.

However, I-555 to Jonesboro is not a great deal shorter than its parent. I-555 is 50 miles, I-55 is 72 miles.

Roadgeekteen

Quote from: Bruce on July 29, 2020, 08:02:43 PM
How many 3dis are busier than their parents?

I-405 in WA gets fairly close, with 209K in Bellevue versus 274K in Seattle, and has an opposite design: plenty of throughput through the "downtown" and fewer lanes in the outer edges, unlike I-5's narrower portion being in downtown.
I-5 and I-405 in LA?
God-emperor of Alanland, king of all the goats and goat-like creatures

Current Interstate map I am making:

https://www.google.com/maps/d/u/0/edit?hl=en&mid=1PEDVyNb1skhnkPkgXi8JMaaudM2zI-Y&ll=29.05778059819179%2C-82.48856825&z=5

TheHighwayMan3561

I-494 in Bloomington between 100 and 35W is pretty equal to I-94 between downtown Minneapolis and downtown St. Paul.
self-certified as the dumbest person on this board for 5 years running

Revive 755

#64
Quote from: ilpt4u on July 28, 2020, 10:41:25 PM
Didn't the St Louis Beltway have a segment numbered I-244 originally? I believe between I-70 in MO and either I-44 or I-55 in MO? Or, basically the West Side?

I-244 was from I-70 to I-55, see https://www.modot.org/sites/default/files/documents/1973_back%5B1%5D.pdf (decent sized pdf file).

Quote from: thspfc5. I don't think it's possible to have too many 3dis, but it is possible to have too many freeways (ahem, Kansas City, St. Louis, Cincinnati)

St. Louis does not have too many freeways.  If anything it's missing a few critical sections such as I-170 south of US 40.

Verlanka

Quote from: Big John on July 29, 2020, 08:14:19 PM
Quote from: Bruce on July 29, 2020, 08:02:43 PM
How many 3dis are busier than their parents?
I believe I-475 has more traffic than I-75 in Macon GA
Particularly since I-75 goes out of the way to go through Macon.

sprjus4

Quote from: Verlanka on July 30, 2020, 05:07:02 AM
Quote from: Big John on July 29, 2020, 08:14:19 PM
Quote from: Bruce on July 29, 2020, 08:02:43 PM
How many 3dis are busier than their parents?
I believe I-475 has more traffic than I-75 in Macon GA
Particularly since I-75 goes out of the way to go through Macon.
I-75 also picks up I-16 traffic heading towards Atlanta from Savannah near Downtown.

How does this impact the volumes?

jmacswimmer

Quote from: sprjus4 on July 29, 2020, 04:50:59 PM
Quote from: jmacswimmer on July 29, 2020, 04:29:25 PM
Quote from: Roadgeekteen on July 29, 2020, 04:05:49 PM
Should I-95 in DC be switched to the western side of the beltway?

I don't think so - I suspect the reason I-95 was put around the eastern side, despite being a few miles longer, is that the eastern side of the beltway passes thru less dense suburbs (relatively-speaking) than the western and northern sides do (which has to squeeze thru Tysons, Bethesda, and Silver Spring to name a few).  On the Maryland side of the beltway, it's quite noticeable that the PG County portion generally has milder curves and a wider ROW compared to the Montgomery County portion.  (The county line, for reference, happens to be a mile west of the I-95 interchange.)

Obviously the eastern side still has its issues too, but the decision-makers probably figured it was the lesser of 2 evils in terms of thru traffic.
Anybody following a GPS would be routed along either the western beltway, or I-495 / I-95 then up the B.W. Parkway to Baltimore to rejoin I-95. At least with Google Maps... it's never recommended I-95 all the way.

Signage and the way VDOT reconfigured the Springfield Interchange to make the I-95 movement a thru, left-hand movement though, directs you to take I-95 all the way however.

There was probably much more of the follow-the-2di-regardless effect (which I've seen discussed in other threads) when the reroute was first made, and maybe still so to a lesser extent today (especially with the configuration of Springfield, as you noted).

Ever since the I-295/DC 295/I-695 interchange was rebuilt and added connections from I-695 to DC 295, GPS's have also started routing people up I-395 to I-695, and then DC 295 into the B-W Parkway.  It's not a bad routing so long as it isn't rush hour.

Quote from: sprjus4 on July 29, 2020, 04:50:59 PM
As for the eastern beltway / I-95 portion, many segments can feel rural, and drivers treat it that way with traffic flow easily cruising at 75 - 80 mph even when heavier despite the artificial 55 mph speed limit. Considering they increased I-95 between Washington and Baltimore and US-50 / I-595 between I-495 / I-95 and Annapolis to 65 mph, I still don't understand why they refuse to increase I-95 / I-495 for most of its length, along with I-270 outside the Beltway, to 65 mph.

Is there really any difference in traffic flow speed on the 65 mph segment of I-95 outside the beltway vs. the 55 mph segment of I-495 / I-95 beltway? Raising it would likely not result in much changes with driver speed, but would bring the speed limit closer to reality.

Agreed, especially on I-270.  I remember once doing 70-75 in the local-express portion and a cop still blowing by me doing at least 80!  I don't think anyone actually goes 55 on I-270, but the cops don't seem to enforce 55 at least.
"Now, what if da Bearss were to enter the Indianapolis 5-hunnert?"
"How would they compete?"
"Let's say they rode together in a big buss."
"Is Ditka driving?"
"Of course!"
"Then I like da Bear buss."
"DA BEARSSS BUSSSS"

hbelkins

I-475 is the reason I don't have I-75 clinched in Georgia.


Government would be tolerable if not for politicians and bureaucrats.

Roadgeekteen

Quote from: sprjus4 on July 30, 2020, 07:04:04 AM
Quote from: Verlanka on July 30, 2020, 05:07:02 AM
Quote from: Big John on July 29, 2020, 08:14:19 PM
Quote from: Bruce on July 29, 2020, 08:02:43 PM
How many 3dis are busier than their parents?
I believe I-475 has more traffic than I-75 in Macon GA
Particularly since I-75 goes out of the way to go through Macon.
I-75 also picks up I-16 traffic heading towards Atlanta from Savannah near Downtown.

How does this impact the volumes?
Probably more traffic heading to Florida than Savannah.
God-emperor of Alanland, king of all the goats and goat-like creatures

Current Interstate map I am making:

https://www.google.com/maps/d/u/0/edit?hl=en&mid=1PEDVyNb1skhnkPkgXi8JMaaudM2zI-Y&ll=29.05778059819179%2C-82.48856825&z=5

I-55

Quote from: jmacswimmer on July 30, 2020, 08:19:55 AM
Quote from: sprjus4 on July 29, 2020, 04:50:59 PM
As for the eastern beltway / I-95 portion, many segments can feel rural, and drivers treat it that way with traffic flow easily cruising at 75 - 80 mph even when heavier despite the artificial 55 mph speed limit. Considering they increased I-95 between Washington and Baltimore and US-50 / I-595 between I-495 / I-95 and Annapolis to 65 mph, I still don't understand why they refuse to increase I-95 / I-495 for most of its length, along with I-270 outside the Beltway, to 65 mph.

Is there really any difference in traffic flow speed on the 65 mph segment of I-95 outside the beltway vs. the 55 mph segment of I-495 / I-95 beltway? Raising it would likely not result in much changes with driver speed, but would bring the speed limit closer to reality.

Agreed, especially on I-270.  I remember once doing 70-75 in the local-express portion and a cop still blowing by me doing at least 80!  I don't think anyone actually goes 55 on I-270, but the cops don't seem to enforce 55 at least.

I did the Beltway and 270 on a Saturday morning with my family last year, they wouldn't allow me to go above 67 give or take, and I nearly rear-ended 2 people because I wasn't nearly fast enough to travel with the 80 mph traffic in the left lanes. After my second near miss, I went ahead and did 75 with no issues and my parents eventually didn't care. What gets me is that I routinely do 70-75 on I-465 in Indianapolis, with the same traffic and speed limit, without repercussion. If you post the limit high, the slow people will catch up and be less of a hazard, and when traffic is tight enough, people will naturally slow down regardless of the limit. Roads are the opposite of Price is Right, the winner is the closest speed limit without going under.
Let's Go Purdue Basketball Whoosh

hobsini2

Quote from: TheHighwayMan394 on July 27, 2020, 02:46:25 PM
Quote from: ethanhopkin14 on July 27, 2020, 01:59:50 PM
Quote from: Scott5114 on July 27, 2020, 12:49:02 PM
Quote from: ethanhopkin14 on July 27, 2020, 09:47:32 AM
The first 4 questions on Wikipedia only yield New York having a complete set of I-x90 within it's state.  Plus, it's Wikipedia.

You don't trust the random roadgeeks on Wikipedia, so you ask...the random roadgeeks on AARoads?

Yes.  Maybe I wanted to have a discussion among roadgeeks instead of staring at Wikipedia for yet another day during a pandemic.  It's getting a bit depressing how much Wikipedia I have been viewing. 

Most of those Wiki editors are the same people who contribute here.
And a few of the wiki editors are quite snooty if you edit some of their stuff that is missing. I made a couple of legit edits on the exit lists for I-55 and I-57 in Illinois and got a nasty response. Just sayin.
I knew it. I'm surrounded by assholes. Keep firing, assholes! - Dark Helmet (Spaceballs)

Scott5114

Quote from: hobsini2 on July 30, 2020, 08:40:43 PM
Quote from: TheHighwayMan394 on July 27, 2020, 02:46:25 PM
Quote from: ethanhopkin14 on July 27, 2020, 01:59:50 PM
Quote from: Scott5114 on July 27, 2020, 12:49:02 PM
Quote from: ethanhopkin14 on July 27, 2020, 09:47:32 AM
The first 4 questions on Wikipedia only yield New York having a complete set of I-x90 within it's state.  Plus, it's Wikipedia.

You don't trust the random roadgeeks on Wikipedia, so you ask...the random roadgeeks on AARoads?

Yes.  Maybe I wanted to have a discussion among roadgeeks instead of staring at Wikipedia for yet another day during a pandemic.  It's getting a bit depressing how much Wikipedia I have been viewing. 

Most of those Wiki editors are the same people who contribute here.
And a few of the wiki editors are quite snooty if you edit some of their stuff that is missing. I made a couple of legit edits on the exit lists for I-55 and I-57 in Illinois and got a nasty response. Just sayin.

Usually this means you broke something without realizing it. Got a link to a diff?
uncontrollable freak sardine salad chef

TheHighwayMan3561

Quote from: hobsini2 on July 30, 2020, 08:40:43 PM
Quote from: TheHighwayMan394 on July 27, 2020, 02:46:25 PM
Quote from: ethanhopkin14 on July 27, 2020, 01:59:50 PM
Quote from: Scott5114 on July 27, 2020, 12:49:02 PM
Quote from: ethanhopkin14 on July 27, 2020, 09:47:32 AM
The first 4 questions on Wikipedia only yield New York having a complete set of I-x90 within it's state.  Plus, it's Wikipedia.

You don't trust the random roadgeeks on Wikipedia, so you ask...the random roadgeeks on AARoads?

Yes.  Maybe I wanted to have a discussion among roadgeeks instead of staring at Wikipedia for yet another day during a pandemic.  It's getting a bit depressing how much Wikipedia I have been viewing. 

Most of those Wiki editors are the same people who contribute here.
And a few of the wiki editors are quite snooty if you edit some of their stuff that is missing. I made a couple of legit edits on the exit lists for I-55 and I-57 in Illinois and got a nasty response. Just sayin.

Not gonna lie, that was my experience as well. I had what I thought were fair edits immediately reverted by people hawking at pages like they had nothing better to do than be Wiki police.
self-certified as the dumbest person on this board for 5 years running

Bruce

There's certain standards for exit lists that have to be followed. All destinations have to match what is on the BGS instead of what "should" be there, which is an opinion that can vary.



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