Why does I-40 extend past Raleigh?

[MantyMadTown]

I-40 basically follows a north-south alignment from Raleigh to Wilmington in North Carolina, where it doesn't make sense as either an even-numbered interstate or a continuation of I-40. Why was the route of I-40 east/south of Raleigh decided the way it was? If it were up to me I would've aligned it along US 264 to Greenville or US 64 to Rocky Mount, where there are currently freeways along their routes and ultimately make more sense as a major east-west corridor.

[TheHighwayMan3561]

I seem to remember it did originally end at Raleigh and the extension to Wilmington was added later. Wilmington as a major port city does make sense to keeping it all as I-40.

[amroad17]

North Carolina wanted an Interstate highway to Wilmington as a way to transport goods from the seaport there.  Also, it was also a way to bring tourists to that area as far as the beaches and the USS North Carolina.

As far as extending I-40, originally I-40 ended at the Death Valley interchange in Greensboro.  Raleigh, in the late 1960's-early 1970's, was one of the six state capitals not served by an Interstate highway.  So, North Carolina built a freeway from the end of the Durham Freeway (NC 147) to Raleigh, ending at the US 1 (now also I-440) beltway on the west side of Raleigh (the freeway portion of Wade Ave) and numbered it I-40 with the understanding that it would be connected to I-85 in Hillsborough.  The Durham Freeway was never considered to be a part of I-40 although it served as a de facto I-40 for years until the section from Hillsborough to the Durham Freeway in Research Triangle Park was completed in the mid to late 1980's.  North Carolina wanted access to Wilmington from Raleigh, so they ended up getting the extension approved from the feds (FHWA or AASHTO-not sure whom) as I-40.  Someone probably thought the distance was too short to use another 2DI.  Besides, at the time, only 73, 97, and 99 were available for north-south numbers (97 or 99 would have worked if it was implemented).

At the time, Greenville and Rocky Mount were "sleepy" towns, places where not much was going on--except for East Carolina University in Greenville.  The Outer Banks was not the tourist destination it is now.  So, at the time, it made sense to extend I-40 to Wilmington--an area with a seaport and a tourist destination.  Besides, North Carolina already had long-term plans to improve US 64.  On a trip to Florida from the Hampton Roads area in 1975, we took US 58, VA 189, and then US 258 into NC to reach I-95 in Kenly, NC.  I-95 was not finished from north of Exit 107 to Exit 145 in Battleboro then.  When we reached the Tarboro area, we entered an interchange that defaulted onto a freeway that was built over the Tar River that went for nearly 3/4 of a mile, then default exited.  That was the only section of the future US 64 freeway built in the immediate area.  The US 64 freeway was going to be state built instead of having the feds assist (90/10).

Answering your east-west corridor comment, the geography of the land in that region is a reason there are even numbered interstates that seemingly go north-south.  From Cape Hatteras, NC to Savannah, the coastline is in a northeast-southwest orientation.  So, any freeway that heads "west" out of Charleston, SC or Wilmington should have an even number, although the freeway may physically go north-south or northwest-southeast.  I-26 is a very northwest-southeast oriented interstate and becomes more north-south upon reaching Spartanburg, SC.  I-26 has a northeast-southwest orientation Sam's Gap to Erwin in Tennessee even though it is signed east-west (east heading southwest and vice versa).  So, NC more than likely decided to use I-40 as the extension number instead of using an odd number up.

I never considered I-40 to not make sense.  You have one number connecting major cities throughout the state of NC.  Plus, as I-40 ends in a zero, it is considered a major cross country Interstate highway.  Even though it doesn't quite go "coast-to-coast" it still crosses nearly 90% of the country.  Besides, who doesn't mind seeing a mileage sign outside of Wilmington posted Barstow, Calif.   2,554.  Or used to.  Looking at googlemaps, it appears that sign (probably because of theft) has been replaced by a Benson  94, Raleigh  123 mileage sign.  Too bad and yet, sad. 

[orulz]

I do recall reading somewhere that the original plan for an I-40 extension past Raleigh would have had it following the US 70 corridor to Morehead City. Wilmington was and is the largest single city along the coast, but when you add the cities along US70 (Smithfield, Goldsboro, Kinston, New Bern, and Morehead City), at least at the time, and likely still today, there are together larger than Wilmington- and let's not also forget that there is a port at Morehead City, too.

In the late 1970s they decided to go for Wilmington. One argument was that US70 was already a four lane highway, while none of the routes into Wilmington were fully four lanes. Another argument was that by directing I-40 towards Wilmington, you can get an efficient interstate route from Raleigh to Fayetteville too, via I-40 and I-95. I-40 was routed due south out of Raleigh, and the I-40/I-95 interchange was put in Benson (rather than Smithfield, where it was originally planned) for this reason.

The rest is history.

Now, 40+ years later, the cities of the central coastal plain are finally getting their interstate: I-42.

[froggie]

^^ To summarize and append a few dates:

- As sparker noted, I-40 originally ended at what used to be I-85 in Greensboro (now US 29/US 70/former-Business-85).

- An extension of I-40 through Raleigh to end at I-95 was requested and approved by FHWA as part of the 1968 Interstate mileage addition.  Early maps of this extension (which were on an old Gribblenation webpage) suggested I-40 would have extended to I-95 in Smithfield instead of Benson.

- Mapmikey (who has done a lot more research into North Carolina than I have as curator of the NCRoads.com Annex) has thus far found no evidence that either NC 147 or Wade Ave were signed or designated as part of I-40.

- Best estimate is that the extension (south)east of I-95 to Wilmington was approved ca. 1978.  The first contracts to build the extension were let in 1980.  Regardless of the timeline, it was added as "non-chargeable Interstate" under 23 USC 103(c)(4)(A).  Which basically means that NCDOT did not receive any dedicated Interstate funding to add it, nor did they receive Interstate Maintenance (IM) funds for upkeep while IM was still a funding category.  IM funding went away with MAP-21 so the primary Federal funding category now for Interstate upkeep is National Highway System (NHS) funding.

- There was a lot of debate for well over a decade as to whether I-40 would go to Moorhead City or Wilmington.  Wilmington won out by the time the extension was added to official plans in 1978.  There was also debate over whether a route to Wilmington should have followed US 421.  Such had been requested from FHWA in the late 1960s but was not approved.

- I-40 from Wade Ave around the south side of Raleigh was completed ca. 1983-84.

- From I-85 to NC 147 was completed by 1989.

- The extension to Wilmington was officially opened on June 28, 1990.

[Beltway]

- As sparker noted, I-40 originally ended at what used to be I-85 in Greensboro (now US 29/US 70/former-Business-85).
- An extension of I-40 through Raleigh to end at I-95 was requested and approved by FHWA as part of the 1968 Interstate mileage addition.  Early maps of this extension (which were on an old Gribblenation webpage) suggested I-40 would have extended to I-95 in Smithfield instead of Benson.
- Mapmikey (who has done a lot more research into North Carolina than I have as curator of the NCRoads.com Annex) has thus far found no evidence that either NC 147 or Wade Ave were signed or designated as part of I-40.

But I still have not seen any documentation of what year the I-40 southerly bypass of Durham originated.

[1995hoo]

Regarding NC-147 as a temporary route, don't forget the northernmost segment of said road, the part between US-15-501 and I-85, didn't open until around 1998, and even then both directions didn't open at the same time (I was living on Erwin Road at the time and I recall how annoying that unopened road was, but I just don't remember anymore which direction opened first). As you may know, the interchange of I-85 and 15/501 was, and still is, a partial interchange, such that without the completed NC-147 it's a bit of a hassle to make thru movements through that little area (coming from Charlotte or Greensboro, I often got off at US-70 west of Durham and then took NC-751 through Duke Forest just to avoid all the annoying traffic lights–my apartment was a decent enough location for getting to anywhere on the Duke campus, but it was a bit of a hassle going to most other places due in part to the Durham Freeway, the railroad tracks across the way, and all the partial interchanges).

Given that situation, it's highly unlikely (as froggie notes) that NC-147 would ever have been signed as "Temporary I-40" or some such, simply because there was no all-freeway route you could follow through Durham if you wanted to go from northbound I-85 to the part of I-40 down by the RTP.

[Henry]

Maybe it did and didn't make sense back then, but the addition of I-42 makes this moot anyway.

[froggie]

But I still have not seen any documentation of what year the I-40 southerly bypass of Durham originated.

In short, it originated with comments/concerns/suggestions FHWA had regarding the recently-approved routing of I-40 through Durham via NC 147.  Effectively early 1969, as the extension of I-40 to I-95 was approved in December, 1968 and their concerns were brought up after initial approval.

Years ago, Adam Prince found an August 1970 corridor study and an August 1973 Draft EIS that covered I-40 from I-85 to RTP.  It got mentioned in an old Gribblenation article on the history of I-40.  Google has digitized the Final EIS, approved in February 1979.  There's a map near the beginning of this that shows all the alternatives considered...five from the corridor study (I'll briefly discuss below) plus a couple more from the revised Draft EIS that is referenced.  The approved alignment is from the revised Draft EIS.

The 1970 corridor study initially looked at 6 alternatives.  Three alternatives departed I-85 near Hillsboro (but east of NC 86 instead of west as was built) and would provide a full bypass south of Durham via various alignments.  One of these three was dropped before the study was released as it went through the Duke Forest.  One alignment was along the original 1968-proposed alignment via NC 147, but with additional lanes and some interchanges removed per FHWA's request (after they approved the extension to I-95).  One alternative would leave I-85 at NC 147 but then use the freeway portion of US 15/501 going south before turning east, roughly parallel to today's MLK Jr Pkwy then rejoining NC 147 at Ellis Rd.  The final alternative stayed on I-85 to the east side of Durham then used US 70 and the now-under-construction East End Connector to NC 147.

The Final EIS makes note that NCDOT recommended one of the full bypass alignments in 1971.  After the Draft EIS was released, public comment and controversy was such that a citzens advisory committee was established through the regional MPO to review the alternatives and make recommendations.  This led to a revised Draft EIS being released in May 1976 and appears to be when the I-85 departure point for the full bypass alternatives was shifted from east of NC 86 to its built location west of NC 86.

The state Board of Transportation approved the recommended alignment in September 1977.

[Avalanchez71]

Was the area "sleepy"  at that time?

[sparker]

^^^^^^^^^
The I-40 extension from Durham through Raleigh to Selma/Smithfield, essentially following US 70 (and which necessitated the long multiplex with I-85) was part of the 1500-mile 1968 Interstate supplemental package.  The Wilmington extension/reroute along NC 50 and US 117, crossing I-95 near Benson, as Adam states, was developed in the mid-80's -- although several Gousha maps had previously shown that alignment as an undesignated future route in regional maps of the period; obviously, I-40 was applied to that corridor at the time.   While there might have been in-state interest in a further Interstate extension to New Bern and Morehead City back then, the legal Interstate definition when the routing still followed US 70 terminated at I-95 near Selma until the Wilmington revision.

[Beltway]

The 1970 corridor study initially looked at 6 alternatives.  Three alternatives departed I-85 near Hillsboro (but east of NC 86 instead of west as was built) and would provide a full bypass south of Durham via various alignments.  One of these three was dropped before the study was released as it went through the Duke Forest.  One alignment was along the original 1968-proposed alignment via NC 147, but with additional lanes and some interchanges removed per FHWA's request (after they approved the extension to I-95).  One alternative would leave I-85 at NC 147 but then use the freeway portion of US 15/501 going south before turning east, roughly parallel to today's MLK Jr Pkwy then rejoining NC 147 at Ellis Rd.  The final alternative stayed on I-85 to the east side of Durham then used US 70 and the now-under-construction East End Connector to NC 147.

So there was an alternative that would have followed NC-147 thru Durham.  I first drove that highway back around 1985, before it had been connected to I-85, and before the I-40 southerly bypass had been fully completed.  NC-147 looked like an early urban Interstate highway design.  Whether that was ever the plan, by default it could have been used for I-40 if that alternative was selected.

[wdcrft63]

- Mapmikey (who has done a lot more research into North Carolina than I have as curator of the NCRoads.com Annex) has thus far found no evidence that either NC 147 or Wade Ave were signed or designated as part of I-40.

In the late 1970s we (my family) lived in Knoxville and my wife had relatives in Raleigh; we would visit them whenever we went the Outer Banks on vacation. So I am very familiar with the freeways of the Triangle in those years. At that time there was a freeway connecting Wade Avenue to Research Triangle Park and the Durham Freeway connecting RTP to downtown Durham (at that time the Durham Freeway ended at Erwin Road, where there is no exit today). The freeway extending Wade Avenue to RTP was definitely signed as I-40 from the Raleigh Beltline (then signed as US 1/64, now I-440/US 1) to RTP, including the current freeway section of Wade Avenue. The Durham Freeway was not signed as I-40 in any fashion and I am sure it never was.

With some searching I turned up a North Carolina state highway map for 1979-80 that shows I-40 extending from the Beltline to RTP. I can remember seeing an I-40 shield immediately west of the Beltline; it was always a welcome sight.

[sprjus4]

To answer the original question, essentially what was said above. It was originally an extension of the original I-40 (it had ended at I-85 outside of Greensboro) to Raleigh & I-95 at Smithfield via the US 70 corridor approved in 1968 when a wave of new interstates were being added to the system throughout the country. Requests were then made in the 1970 to build an interstate parallel to US 74 between Asheville and Wilmington, an interstate paralleling US 421 from Greensboro to Wilmington, and extending I-40 to Morehead City from the proposed Smithfield terminus. All of those proposals were rejected. In 1978, the state had switched the routing of I-40 to meet I-95 at Benson instead, and to continue to Wilmington. Construction then happened mostly through the 80s.

Here's a good article explaining all of this more in detail - http://www.gribblenation.com/ncpics/history/i40.html

For opening dates...

• I-40 between I-85 and the Durham Freeway opened in 1988 & 1989.
• I-40 between the Durham Freeway and Wade Ave opened in 1971.
  
• I-40 between Wade Ave and I-440 (not originally called I-440) opened in 1984
• I-40 between I-440 and I-95 at Benson opened in phases between 1988 and 1990.
• I-40 between I-95 and Wallace opened in phases between 1987 and 1991.
• I-40 between Wallace and Wilmington opened in 1983.

Here's a more detailed map on the openings - https://goo.gl/X81wC8

[sprjus4]

Given that situation, it's highly unlikely (as froggie notes) that NC-147 would ever have been signed as "Temporary I-40" or some such, simply because there was no all-freeway route you could follow through Durham if you wanted to go from northbound I-85 to the part of I-40 down by the RTP.

IIRC, parts of I-85 Business through Lexington and High Point that have at-grade intersections and driveways signed as "Temporary I-85" until I-85 opened bypassing those cities in 1984.

[wdcrft63]

The Wade Avenue Extension, between I-440 and the modern I-40, designated as I-40 between 1971 and 1984, is a 3-mile, 4-lane, interstate-quality freeway.  It has interchanges at Blue Ridge Road and Edwards Mill Road; the latter serves the PNC Arena and Carter-Finley Stadium. The road has no posted route number (there is a hidden secondary route number). Everyone who lives in the area calls it Wade Avenue and knows where it is and where it goes, but for visitors I think it should have a route number. It could be I-740, or if we think NC has enough interstate numbers it could at least be NC 740.

[roadman65]

My old Exxon map shows the the Durham Freeway and I-40 did not interchange like it does today. Both defualted without a turn at the current exchange. It required a breezwood at the end to get to I-85 and that map I saw it on showed two segments and no concurrency with I-85 then.

[MantyMadTown]

It looks like Interstate 87 is planned along the US 64 corridor from Raleigh to Rocky Mount and Williamston and continue on to Elizabeth City and eventually Norfolk (via US 17). So at least there will be an interstate along the corridor I mentioned.

[LM117]

It looks like Interstate 87 is planned along the US 64 corridor from Raleigh to Rocky Mount and Williamston and continue on to Elizabeth City and eventually Norfolk (via US 17). So at least there will be an interstate along the corridor I mentioned.

There's also Future I-587, which follows US-264 between Zebulon and Greenville.

[goobnav]

The Wade Avenue Extension, between I-440 and the modern I-40, designated as I-40 between 1971 and 1984, is a 3-mile, 4-lane, interstate-quality freeway.  It has interchanges at Blue Ridge Road and Edwards Mill Road; the latter serves the PNC Arena and Carter-Finley Stadium. The road has no posted route number (there is a hidden secondary route number). Everyone who lives in the area calls it Wade Avenue and knows where it is and where it goes, but for visitors I think it should have a route number. It could be I-740, or if we think NC has enough interstate numbers it could at least be NC 740.

If it's a 3 digit interstate, it would have to be a even number as it connects on both ends to an interstate, I-40 and 440.  Could be I-640 now that the Outer Beltline will be I-540.  NC 740 could work and have it signed from Capital to 40, everybody living here for 20+ years will still call it Wade Avenue.

[Life in Paradise]

In a better world (I'm not going to say perfect world), I-40 would be changed to what is being put in as I-42 (to maintain more of the east/west flavor of the road), and I-74 would become what is now I-40, and I-73 would keep the route south of Greensboro into South Carolina.

[sparker]

In a better world (I'm not going to say perfect world), I-40 would be changed to what is being put in as I-42 (to maintain more of the east/west flavor of the road), and I-74 would become what is now I-40, and I-73 would keep the route south of Greensboro into South Carolina.

So -- I-40, I-74, and I-85 would be a "triplex" between Greensboro and west of Durham?  And what designation would be applied to the Interstate portion of the US 74 corridor across the south tier of the state (not that there aren't plenty available!)?  Seems like a lot of effort just to get rid of the 73/74 multiplex along US 220.  If one really wanted to maintain the general E-W aspect of I-40, it would subsume at least part of the nascent I-87 (at least out to US 17), with I-42 becoming something like I-38, and the N-S portion of I-40 from Raleigh to Wilmington a southern section of I-97 or I-99.  But we're now getting into areas best reserved for the fictional section.

[sprjus4]

In a better world (I'm not going to say perfect world), I-40 would be changed to what is being put in as I-42 (to maintain more of the east/west flavor of the road), and I-74 would become what is now I-40, and I-73 would keep the route south of Greensboro into South Carolina.

So -- I-40, I-74, and I-85 would be a "triplex" between Greensboro and west of Durham?  And what designation would be applied to the Interstate portion of the US 74 corridor across the south tier of the state (not that there aren't plenty available!)?  Seems like a lot of effort just to get rid of the 73/74 multiplex along US 220.  If one really wanted to maintain the general E-W aspect of I-40, it would subsume at least part of the nascent I-87 (at least out to US 17), with I-42 becoming something like I-38, and the N-S portion of I-40 from Raleigh to Wilmington a southern section of I-97 or I-99.  But we're now getting into areas best reserved for the fictional section.

The numbering is weird, but there's not much issues with it. Most people have been accustomed, and switching the numbers around just to meet a grid would be a waste of money, time, and effort. Like you said, purely fictional.

[Mapmikey]

Fun Fact about I-40 on the Wilmington end...it was first designated as NC 132 from Jan 1983 to Aug 1984 with the road northwest to US 117 Castle Hayne reduced to secondary status before reverting back after the I-40 designation.

[Tom958]

...
- An extension of I-40 through Raleigh to end at I-95 was requested and approved by FHWA as part of the 1968 Interstate mileage addition.  Early maps of this extension (which were on an old Gribblenation webpage) suggested I-40 would have extended to I-95 in Smithfield instead of Benson.

So, if I-40 was intended to end near Smithfield, giving the freeway to Wilmington a north-south number such as 97 would've involved either having what's now I-40 seemingly arbitrarily change numbers where the Clayton bypass was eventually to begin, or building the Clayton bypass decades earlier than otherwise justified. I once saw a reference to "the Wilmington-Benson freeway," which implied that there was a concept for a Benson-Raleigh freeway that predated the full Raleigh-Wilmington corridor. As unambiguously north-south as it is, numbering it as I-40 would've been pretty crazy, but extending it to Wilmington made an I-40 designation more... agreeable.