Interstates that changed the most from planning stage to building stage

[planxtymcgillicuddy]

In very early maps 90 followed US 18 across Wisconsin and Iowa before being moved to the Minnesota route.
The first Interstate 39 though it's not a chargeable route ran along IL 2 IL 26 IL 89 and IL 121 including the now I 155 from Rockford to Decatur.
Then we have myths about 74 . It was going to run through either Kewanee or Monmouth neither is true it always followed the current route.

Did not know I-90 was slated to run along US-18. Could this be why Mason City wanted I-35 closer to them?

And IIRC, there's still ghost ramps on I-72 in Decatur where I-39 would have met it

[JCinSummerfield]

I-92.  Went from the drawing table to the waste basket.

[silverback1065]

I-92.  Went from the drawing table to the waste basket.

what route was this supposed to take? 

[roadman65]

I-78 in Lehigh Valley. It was originally to use US 22, then was proposed to run further south of Allentown, but then was constructed to concur with PA 309 as it does now.

[planxtymcgillicuddy]

I-92.  Went from the drawing table to the waste basket.

what route was this supposed to take? 

I don't think anybody really knows for sure. I've seen at least 3 different routes proposed for it

[skluth]

I-92.  Went from the drawing table to the waste basket.

what route was this supposed to take? 

I don't think anybody really knows for sure. I've seen at least 3 different routes proposed for it

I thought I-92 is what eventually became I-94 in Michigan

[abefroman329]

I-92.  Went from the drawing table to the waste basket.

what route was this supposed to take? 

I don't think anybody really knows for sure. I've seen at least 3 different routes proposed for it

I thought I-92 is what eventually became I-94 in Michigan

Wikipedia has two "I-92" pages - one about current I-94, and this is the other one: https://en.wikipedia.org/wiki/East%E2%80%93West_Highway_(New_England)

[kphoger]

I-92.  Went from the drawing table to the waste basket.

what route was this supposed to take? 

I don't think anybody really knows for sure. I've seen at least 3 different routes proposed for it

I thought I-92 is what eventually became I-94 in Michigan

That's one of them, yes.  See below.

But I've also read that it was the considered as the number for the proposed East-West Highway in New England.  However, I haven't been able to find any official documentation to back that up.

[Hot Rod Hootenanny]

I thought I-92 is what eventually became I-94 in Michigan

That's one of them, yes.  See below.

But I've also read that it was the considered as the number for the proposed East-West Highway in New England.  However, I haven't been able to find any official documentation to back that up.

That map reminds me that I-77 went from two short stubs, one going NE out of Detroit and the other going between Cleveland and Canton (which may or may not been cosigned with I-80 & 90 between Cleveland and Toledo depending on which documents you read) to going from Cleveland to Columbia, SC.

[SilverMustang2011]

I-75 was to end in Tampa. I-4 was to run from St. Pete to where it is now.

The former got extended to Miami and the latter got truncated to Tampa.

Actually that was the case for many years, as I remember I-75 ending at I-4 in the 70s.  There were no plans for I-75 beyond that point until they made the extension and incorporated what is now known as Everglades Parkway (then known as Alligator Alley).  I guess way too many people move to the Sarasota/Port Charlotte/Fort Myers/Naples corridor that they had to put some sort of interstate there.

Adding onto that, the section of I-275 between the Howard Frankland Bridge and Downtown Tampa has been planned or designated as I-4, I-75, and finally I-275. Not a design change but a lot of name changes.

[Tom958]

i've always wondered why 70 ends where it does in utah, it makes sense for it to end in SLC. was 70 always supposed to go where it is in Denver? Skirting the north side of town instead of going downtown?

https://www.fhwa.dot.gov/infrastructure/covefort.cfm

On October 18, 1957, Secretary of Commerce Sinclair Weeks announced the segments designated with the expanded Interstate mileage. The additions included the western extension of I-70 to Cove Fort. An October 18 press release explained:

The route westward from Denver is a modification of one proposed by the states of Colorado and Utah. The proposal involved a route from Denver to Spanish Fork, Utah en route to Salt Lake City which would largely duplicate service provided by the designated Denver-Cheyenne-Salt Lake City route [via I-25 from Denver to Cheyenne and I-80 from Cheyenne to Salt Lake City]. By bending the western end of the route southward to provide a direct connection between Denver and southern Utah, it will be possible to serve traffic moving back and forth between Southern California and the Denver region.

The press release did not explain how the BPR had decided on a terminus at Cove Fort, other than its desire to end the route in a way that enhanced access to southern California. The FHWA's files do not explain the decision, either. However, because the mountains and forests in central Utah limited the options, the Cove Fort-Sevier road appears to have been the best choice among the few available for reaching future I-15 from Grand Junction, Colorado, by the most direct, practicable route on the way to southern California.

However...

According to State highway historian Ezra C. Knowlton, the news hit Utah officials "like a bombshell." The State had considered routings along U.S. 40 and U.S. 50, but had settled on the U.S. 50 routing to Spanish Fork. "No responsible local official had even suggested the so-called Salina Canyon-Cove Fort routing." Knowlton said:

This suggestion obviously pleased the people of south-central Utah but naturally aroused stormy opposition from those favoring a junction with U.S. 91 at Spanish Fork. Utah County people took the lead in demanding that the State Road Commission conduct a public hearing on the government's "arbitrary" action, threatening an injunction against the commission if this were not done. [Knowlton, Ezra C., History of Highway Development in Utah, Utah State Department of Transportation, 1967, page 597]

Governor Dewey Clyde, an engineering instructor at Utah State University who took office in 1957, joined with the State's congressional delegation in consulting with the BPR. They learned about General Yount's position that the routing to Spanish Fork could not be justified. According to Knowlton, the Governor concluded that, "Utah had no choice but to accept the Cove Fort routing, or have none at all."

The Utah State Highway Commission held a public hearing at the State Capitol prompting "spirited testimony" on both sides of the issue. Knowlton explained that, "Southern Utah people spoke in favor, and those from the north-central part of the state spoke against the newly proposed route." Nevertheless, the decision stood. A December 1957 evaluation by the Research Department of the Utah State Road Commission on the economic and traffic service of the Denver-Cove Fort routing, stated:

There was, undoubtedly, a great deal of merit in the original proposal for a Denver-Salt Lake connection; however, sight must not be lost of the fact that the Salt Lake area is already served by two major Interstate routes, one running North-South [I-15) and one East-West [I-80], and that the terminus at Cove Fort, as presently proposed, shortens the distance from Denver to Los Angeles by approximately 200 miles.

Knowlton stated that the route was important to Utah as well as Colorado because it would increase Interstate Construction funding for both States and the trans-mountain link between the two States could not come any other way. He added:

Utah's Road Commission was probably more shocked at the manner in which the news of the Washington decision on the Cove Fort route was released than they were at the decision. Surely this inadvertent news release from Washington was one of the most serious breaches of sound public relations experienced in the entire history of the federal road agency.

The commission approved the Cove Fort terminus by resolution on January 20, 1958, with the resolution describing the routing as...

[US 89]

Utah also had a pretty sizable shift in the proposed route of I-15 through Nephi. Originally 15 was supposed to pass directly through town or on the west side, in the vicinity of the railroad track, but ended up bypassing the town to the east.

This is perhaps most notable because this was still a gap in the early 1980s (you can still see where traffic defaulted over onto Old 91 between Mona and Nephi on satellite), which was when mile-based exit numbers were first introduced. With a routing through Nephi still undecided, a guess had to be made as to how much mileage would increase over that section so that the exits north of it could be numbered appropriately. They guessed a bit too high, and for the next 20 years after the Nephi segment did open, all exits north of there, including through the high-traffic Wasatch Front region, were 3 or 4 higher than the corresponding milepost value. They were given more mileage-appropriate numbers in 2004/05.

[vdeane]

which would largely duplicate service provided by the designated Denver-Cheyenne-Salt Lake City route [via I-25 from Denver to Cheyenne and I-80 from Cheyenne to Salt Lake City].

Meanwhile, Google Maps doesn't even suggest that as an option, instead cutting the corner via US 287.  The only way to get Google to show an all-interstate route between Denver and SLC is to manually modify it yourself.

[rlb2024]

Interstate 10 was originally envisioned to go farther south between New Orleans and the Mississippi Gulf Coast, along the routing of US 90.  Interstate 59 would have met I-10 in east New Orleans, along the routing of US 11.  There was no Interstate 12 in the original 1957 plan.  (I hate to think how much longer these routings would have been out of commission after Hurricane Katrina.)

The first mapping I saw of I-12 had it intersecting I-59 farther north and not connecting to I-10 on its east end, so it would not have been a viable bypass of New Orleans as it is now.

[The Nature Boy]

i've always wondered why 70 ends where it does in utah, it makes sense for it to end in SLC. was 70 always supposed to go where it is in Denver? Skirting the north side of town instead of going downtown?

It ends where it does in UT because it forms part of the fastest LA-Denver corridor

If I-70 didn't extend westward then driving from Denver to....well anywhere west of Colorado would have been A LOT harder. It's the only east-west route across the state. The only other option is driving up to I-80.

[TEG24601]

There were plans for 80N, now I-84(W) to eventually reach the Oregon Coast.


I-90 in Washington was originally supposed to end at US/SR 99. The Alaskan Way Viaduct even had the stubs from the time it was built.  But the massive delay in completing I-90 from Bellevue to Seattle caused it to no longer be considered a viable connection, especially as even in the early 90s there was talk about replacing that section of SR 99, and they didn't want to spend the money on a connection, only to have to tear it down and figure out another solution in the future.


I have seen plans for I-82(W) to both be the Interstate over Snoqualmie Pass (now I-90), with I-90 running over Steven's Pass instead, and to have it turn West at Yakima and travel over US-12, over White Pass, and end in either Olympia or Tacoma.

[SkyPesos]

I thought I-92 is what eventually became I-94 in Michigan

That's one of them, yes.  See below.

But I've also read that it was the considered as the number for the proposed East-West Highway in New England.  However, I haven't been able to find any official documentation to back that up.

That map reminds me that I-77 went from two short stubs, one going NE out of Detroit and the other going between Cleveland and Canton (which may or may not been cosigned with I-80 & 90 between Cleveland and Toledo depending on which documents you read) to going from Cleveland to Columbia, SC.

There's one version of the initial plains map with the number 79 on the Cleveland-Canton corridor, and current I-79 not existing at all (I think it's the same map with I-80 on the PA Turnpike). The combination of both of the different I-77 and I-79s surely would've left a big gap in WV's interstate network.

[TheHighwayMan3561]

When I-35 was originally proposed for its extension through downtown Duluth, the plan was for an elevated freeway rather than the tunnels (the purpose behind these vastly differing options was quite similar, which was to protect the freeway from Lake Superior's wintertime wrath). There was grave community concern for the historic buildings along E. Superior Street like the Fitger's complex, as well as popular greenspace like the Duluth rose garden and Leif Erikson Park that ultimately resulted in the tunnel choice coming to development.

[Bruce]

I have seen plans for I-82(W) to both be the Interstate over Snoqualmie Pass (now I-90), with I-90 running over Steven's Pass instead, and to have it turn West at Yakima and travel over US-12, over White Pass, and end in either Olympia or Tacoma.

I've never heard of I-82 being assigned for Snoqualmie Pass. The White Pass you're thinking of was probably the Naches Pass Tunnel proposal, which was brought up in 1959 and studied in the following years, later as SR 168 (which remains on the books but unbuilt and unfunded).

[3467]

Two non chargeable diverged from their original proposal in Illinois
I 39 First proposed from Rockford to Dixon to East Peoria to Lincoln to Decatur.
The current route was in the largest Interstate system but the first suggested corridor was the winding one . I 155 was built in that original corridor though.
I 88 was first aligned where US 30 is now.
The unused 64 corridor was added to the supplemental freeway system and partially built.

[US20IL64]

I-90 and I-94 were flipped in IL, IN. Also, 90 re-routed from current I-290 to NW route, by O'Hare Airport.

And, many cancelled Interstates/Freeways, nationwide.

[Henry]

I-40 in NC has undergone so many changes that it's impossible to keep up. Originally it ended at I-85 in Greensboro until an eastern extension came about in the 80s. First the extension was to go to Morehead City (where the planned I-42 will end eventually), but Wilmington wanted it more, so it went there instead. Then in the 90s, it was rerouted to the south of Winston-Salem, and a decade later, it was also rerouted to the south of Greensboro for several months before numerous complaints about the new route forced an about-face. (One thing to note is that the eastern half of the former reroute is currently occupied by the new alignment of I-85, so now the two 2di's converge approximately eight miles east of where they originally met.)

I-95 in New Jersey, perhaps?

Along with I-95 in DC and Boston.

And Baltimore too. That section of I-95 is the last one in MD to be completed because of major changes regarding its routing: First it was planned to run right through downtown, then it was moved to the south of downtown to cross the harbor on a high bridge (was it going to be suspension, cable-stayed or other?), but eventually good sense won out, and the Fort McHenry Tunnel was constructed under the harbor instead. As a result, the Harbor Tunnel finally got big-time relief, and even underwent a two-year reconstruction period shortly after the newer tunnel had opened to traffic.

[Avalanchez71]

Wasn't I-24 planned to run up Vincennes, IN then across to Saint Louis?

[3467]

I remember there were several alignments proposed for 24 but not sure if the routings.
I am sure all those were West of 57. The idea of East through Carbondale was later like 1965 with the Supplemental Freeway system.
There have been multiple corridors proposed and studied there. A 4lane expressway between Murpheysboro and Pickneyville lives on.

[mgk920]

I-90 and I-94 were flipped in IL, IN. Also, 90 re-routed from current I-290 to NW route, by O'Hare Airport.

And, many cancelled Interstates/Freeways, nationwide.

IMHO, I-90 just has a 'feel' of having been originally planned to use use the US 12 corridor, IL 53 and I-290 between downtown Chicago and Madison, WI, There are too many 'clues' along the way for me to think otherwise.

Mike