Bizarre Highway Numbering Conventions

[BostonUrbEx]

Just a general thread on numbering of highways...


Anyone know how I-190 exists? It doesn't touch I-90 at all. It can't run concurrently with I-290 to I-90, and it definitely starts at I-290. So what gives? How's this "legal" under the Interstate Highway Act?

 

[BostonZest]

For background purpostes, Wikipedia has a long entry on this topic.
http://en.wikipedia.org/wiki/United_States_Numbered_Highways

As does the Federal Highway Administration.
http://www.fhwa.dot.gov/infrastructure/numbers.cfm

 

[HalcyonEra]

Just a general thread on numbering of highways...


Anyone know how I-190 exists? It doesn't touch I-90 at all. It can't run concurrently with I-290 to I-90, and it definitely starts at I-290. So what gives? How's this "legal" under the Interstate Highway Act?

Interesting question. I would suspect it goes back to the early designations. 395 was supposed to run through Worcester up to Nashua along that same route with 290 going from Worcester to Waltham. By the time 395 and 190 were finally completed, our esteemed public officials probably thought it would not be worth it to rename the Worcester N/S portion of 290 to 395. That doesn't explain why 190 isn't 795 though (695 was the Inner Belt and 595 was the middle circumferential loop).

 

[Equilibria]

Interesting question. I would suspect it goes back to the early designations. 395 was supposed to run through Worcester up to Nashua along that same route with 290 going from Worcester to Waltham. By the time 395 and 190 were finally completed, our esteemed public officials probably thought it would not be worth it to rename the Worcester N/S portion of 290 to 395. That doesn't explain why 190 isn't 795 though (695 was the Inner Belt and 595 was the middle circumferential loop).

Not exactly. The corridor was originally proposed as MA-12 from Connecticut to Manchester, and it was only given the 395 designation after it had been truncated. I believe that the numbering guidelines state that a 1XX interstate must be a spur or "to" route off of either I-XX or any other three-digit of the XX family. Since I-190 is a spur from I-290, it's kosher. (http://www.bostonroads.com/roads/I-190_MA/)

Also, the 190 designation actually predates the 395 designation by 10 years, hence why they gave essentially the same road 2 different numbers. 795 would have made little sense, since the road doesn't hit I-95 or I-495. Extending the I-395 designation through Worcester to Leominster would make more sense. If RI-146 is ever brought to interstate grade, I-190 is a pretty good candidate to be extended to Providence.

 

[F-Line to Dudley]

Not exactly. The corridor was originally proposed as MA-12 from Connecticut to Manchester, and it was only given the 395 designation after it had been truncated. I believe that the numbering guidelines state that a 1XX interstate must be a spur or "to" route off of either I-XX or any other three-digit of the XX family. Since I-190 is a spur from I-290, it's kosher. (http://www.bostonroads.com/roads/I-190_MA/)

Also, the 190 designation actually predates the 395 designation by 10 years, hence why they gave essentially the same road 2 different numbers. 795 would have made little sense, since the road doesn't hit I-95 or I-495. Extending the I-395 designation through Worcester to Leominster would make more sense. If RI-146 is ever brought to interstate grade, I-190 is a pretty good candidate to be extended to Providence.

395 was MA/CT 52 until 1983 when the two states traded in some unused interstate miles as an economic development redesignation of the corridor. States requested and expected it to be assigned 290, but the feds pulled a WTF? and gave it 395 instead.

Had the CT 8 expressway made it from Winsted to the Pike as originally planned that would've been 390. US 7 expressway to Pike might've been another x90.


I agree...the 190 designation is the logical one for 146 since it adds a third control city to the contiguous route in Fitchburg and better-highlights that straight shot as a complete corridor. It would be better if that came with a cleanup of the messed-up numbering: truncate 290 at 190, extend 395 to the 146 interchange, 190 taking over the downtown midsection. But they could do it with a 290/190 concurrency if the state is wedded to the current numbering. Even though RI has its own short 146 gap in N. Smithfield to cover and a whole lot of below-standard expressway south of there to upgrade before it can get an interstate...simply filling the Millbury-Sutton gap is good enough for securing an interstate designation as far south as 295 and qualifying Providence as an official control city. Substandard RI 146 between 295 and 95 can be earmarked as a future interstate whenever RIDOT finishes it.

 

[Equilibria]

I agree...the 190 designation is the logical one for 146 since it adds a third control city to the contiguous route in Fitchburg and better-highlights that straight shot as a complete corridor. It would be better if that came with a cleanup of the messed-up numbering: truncate 290 at 190, extend 395 to the 146 interchange, 190 taking over the downtown midsection. But they could do it with a 290/190 concurrency if the state is wedded to the current numbering. Even though RI has its own short 146 gap in N. Smithfield to cover and a whole lot of below-standard expressway south of there to upgrade before it can get an interstate...simply filling the Millbury-Sutton gap is good enough for securing an interstate designation as far south as 295 and qualifying Providence as an official control city. Substandard RI 146 between 295 and 95 can be earmarked as a future interstate whenever RIDOT finishes it.

Yeah, the crazier way to do it (following the nominal spirit of Interstate naming) is to give the route the I-695 designation from Leominster to the Bourne Bridge, replacing I-190, MA-146, RI-146 and I-195. On a map, that route forms a far beltway around Boston, connecting all of its surrounding metropoli (including Manchester in theory), and Boston's beltways all currently carry an X95 designation.

Frankly, though, I see the benefit in allowing locals to continue to use traditional names for roads. When MA-146 is an interstate, it can get a new number. Other than that, it's probably best to leave the current numbers alone...

 

[HalcyonEra]

Not exactly. The corridor was originally proposed as MA-12 from Connecticut to Manchester, and it was only given the 395 designation after it had been truncated. I believe that the numbering guidelines state that a 1XX interstate must be a spur or "to" route off of either I-XX or any other three-digit of the XX family. Since I-190 is a spur from I-290, it's kosher. (http://www.bostonroads.com/roads/I-190_MA/)

Also, the 190 designation actually predates the 395 designation by 10 years, hence why they gave essentially the same road 2 different numbers. 795 would have made little sense, since the road doesn't hit I-95 or I-495. Extending the I-395 designation through Worcester to Leominster would make more sense. If RI-146 is ever brought to interstate grade, I-190 is a pretty good candidate to be extended to Providence.

I swear I saw old drawings of 84 going to Manchester, crossing Route 2 just west of Mt. Wachusett and east of the Gardner. And this one separately to Nashua.

 

[HenryAlan]

My guess is that original plans might have connected it to I-90. Not sure, but I do know for certain that this isn't unique. In CA, I-105 runs between I-405 and I-605, but does not directly connect to I-5, even though it comes within a mile or so of making it.

 

[Equilibria]

My guess is that original plans might have connected it to I-90. Not sure, but I do know for certain that this isn't unique. In CA, I-105 runs between I-405 and I-605, but does not directly connect to I-5, even though it comes within a mile or so of making it.

As I've brought up before in threads, my favorite is I-238 in CA. The Bay Area has only one 2-digit interstate in I-80, so when they got to I-980 they had to append the next 3-digit number to a non-existent 2-digit one. I'm not sure why they chose 38. This means that technically the Bay Area is not served by a single N/S Interstate Corridor.

Similarly, due to Texas's unique state highway numbering system, Austin's metro area of 1.5 million people is served by a single interstate highway of any designation, I-35. All the other freeways have state route numbers.

 

[F-Line to Dudley]

I swear I saw old drawings of 84 going to Manchester, crossing Route 2 just west of Mt. Wachusett and east of the Gardner. And this one separately to Nashua.

Westminster where 2 and 140 go concurrent is where I-84 was supposed to terminate. Basically positioning 84 and 190 on opposite ends of Fitchburg at the city line. Of course, 2 was supposed to be its own 'north Pike' going cross-state in the original plans so this probably would've been a junction of two 2-digit interstates. Follow the power line ROW's, forest land, and parts of Routes 49 and 31 from Sturbridge to see approximately where it would trace.

 

[omaja]

As I've brought up before in threads, my favorite is I-238 in CA. The Bay Area has only one 2-digit interstate in I-80, so when they got to I-980 they had to append the next 3-digit number to a non-existent 2-digit one. I'm not sure why they chose 38. This means that technically the Bay Area is not served by a single N/S Interstate Corridor.

Similarly, due to Texas's unique state highway numbering system, Austin's metro area of 1.5 million people is served by a single interstate highway of any designation, I-35. All the other freeways have state route numbers.

I-238 is derived from the route's old CA-238 designation and has nothing to do with traditional Interstate route number conventions. Another doozy: NY with all of its orphaned I-x78 routes when I-78 was truncated to NJ.

I've often thought that the split I-290/I-395 designations never made any sense, but I think the rationale is that both routes serve two distinct purposes: I-290 is a loop through downtown Worcester while I-395 is a radial connector from Worcester/I-90 to New London/I-95. Two purposes, two route numbers.

 

[Ron Newman]

Wasn't I-84 supposed to terminate in Providence? Only after eastern CT rejected it was it sent up to I-90 in Sturbridge instead.

 

[Equilibria]

I-238 is derived from the route's old CA-238 designation and has nothing to do with traditional Interstate route number conventions. Another doozy: NY with all of its orphaned I-x78 routes when I-78 was truncated to NJ.

Well, it has a little to do with it - if there had been an I-238 they wouldn't have done it. CA also tends to name state routes with what they wish the interstate number would be, so it may be a chicken or egg thing. The Wikipedia entry on this is pretty fascinating, though.

I've often thought that the split I-290/I-395 designations never made any sense, but I think the rationale is that both routes serve two distinct purposes: I-290 is a loop through downtown Worcester while I-395 is a radial connector from Worcester/I-90 to New London/I-95. Two purposes, two route numbers.

I actually think the reason had more to do with them being entirely different projects. I-395 was CT project while I-290 was an MA project. Your explanation makes plenty of sense too. I don't think, though, that there's much rational defense for the hilarious sign on I-290 at the Pike that tells you that the road you're on just randomly changed names for no reason.

Wasn't I-84 supposed to terminate in Providence? Only after eastern CT rejected it was it sent up to I-90 in Sturbridge instead.

I-84 was always to terminate in Providence. I-86 was the road initially headed to Route 2. Then again, I doubt that at the time the longer version was planned any numbers had been assigned to any of the corridors.

 

[F-Line to Dudley]

Wasn't I-84 supposed to terminate in Providence? Only after eastern CT rejected it was it sent up to I-90 in Sturbridge instead.

No. Until 1969 I-84 was signed to the Pike like it is today, concurrent with CT/MA 15 from East Hartford to the Pike. I-82 was the provisional designation from Manchester to Provincetown, with I-195 supposed to be a temporary designation until all gaps were filled (including a hideous downtown Providence demolition direct-connecting the 195 and 6 alignments). The I-86 switch and 82/84 swap happened the day the West Hartford-Southington segment opened in '69 and 84 was finally contiguous from Scranton, PA to Hartford. I-86 only lasted for 15 years total before they changed it back and formally canceled the Providence extension.


The extension to Westminster/Fitchburg and 2 was deleted before the 84/86 switch, so that was always intended to be 84. The 82/84/86 shuffle came about in part because the 84 mileage stretching outside CT was so insignificant after the cancellation and they wanted it to look like a more substantial corridor on the national map.

 

[Roxxma]

There's also an I-84 running from Portland Oregon to just east of Salt Lake City. Were there ever any plans to connect the two?

 

[Shepard]

Do highway numbers matter practically, or is this just antiquarian curiosity?

In the age of GPS, I don't think anyone navigates based on "aha, this three-digit interstate I'm approaching indicates a spur into the heart of nearby city that will not re-connect back with the mainline I'm currently traveling."

Not that anyone could ever have really done that anyway. I once tried that approach driving up the East Coast thinking that I-95 would get me where I needed to go. Oops - ended up in an infinity-loop around Trenton. Lesson learned.

 

[F-Line to Dudley]

There's also an I-84 running from Portland Oregon to just east of Salt Lake City. Were there ever any plans to connect the two?

Duplicate 2-digit numbers on opposite ends of the country are fully legal. There's no way to make the 2-digit system work without them since the numbering scheme on the even numbers is dependent on latitude vs. the nearest divide-by-10 interstates.

84, 86 (thanks to the new one in NY/PA), 88, 76 all have duplicates in the eastern and western U.S. I-8x and I-7x are the only 2-digit brackets totally full, so the only way to add new routes at similar latitude is with widely-separated duplicates. I-82 is fair game for an eastern dupe if I-384 ever makes it to RI and gets a trade-up into the 2-digit category.

 

[BostonUrbEx]

All interesting discussion, I love it!


Somewhat related... why does the Northeast Expressway/US-1 not have exit numbers? AFAIK, the Northwest Expressway/US-3 does, and so does MA-2.

 

[F-Line to Dudley]

All interesting discussion, I love it!


Somewhat related... why does the Northeast Expressway/US-1 not have exit numbers? AFAIK, the Northwest Expressway/US-3 does, and so does MA-2.

Because Massachusetts.


Hey...at least we no longer do the utterly batshit "Route 128 is Exit 25...EVERYWHERE" gimmick with 2 + 2 = 5 arithmetic anymore.

 

[HalcyonEra]

Westminster where 2 and 140 go concurrent is where I-84 was supposed to terminate. Basically positioning 84 and 190 on opposite ends of Fitchburg at the city line. Of course, 2 was supposed to be its own 'north Pike' going cross-state in the original plans so this probably would've been a junction of two 2-digit interstates. Follow the power line ROW's, forest land, and parts of Routes 49 and 31 from Sturbridge to see approximately where it would trace.

That makes sense. I remember driving on 49 once and being amazed at how wide it was with nothing around it and limited traffic.