Sorry for what looks like a confusing thread title - I couldn't think of a better way to phrase it. You'll probably pick up on what I mean once I explain it a little more.
Anyway, I was just thinking back to some family trips from a while ago. Back in the early aughts, whenever we drove from Columbia, MO (where I lived at the time) to St. Louis, one thing I remember was that back then, US 40/61 through St. Charles County (between the I-70 junction at Wentzville and the Daniel Boone Bridge) still had a lot of traffic lights and at-grade intersections, and it didn't become I-64 until after crossing the bridge into Chesterfield. For a while, heading eastbound, the first numbered exit was Exit 17 at Boone's Crossing; at the time, I had come to realize that the exits were numbered in anticipation of I-64 being extended west to meet I-70 at Wentzville - which, sometime around 2007-08 (I believe), it was.
That brings me to another example from Missouri - namely, when we were headed home from a trip to Madison, WI, in 2006, we drove west on I-72 through Illinois and crossed into Missouri at Hannibal. As I recall, the first exit after the bridge (on the Hannibal bypass) was marked as Exit 157, but soon after that, I-72 ended and the road continued west as US 36 with no additional numbered exits. Feeling curious, sometime after we got home I went into Microsoft Streets & Trips (anyone remember that software?) and traced west 157 miles on US 36 from Hannibal. That brought me to the junction with I-35 at Cameron, which suggests to me that MoDOT had plans to extend the I-72 designation west to that point; I'm not sure if such a plan is still on their agenda. (I would say most likely not; next June will mark 15 years since that trip I alluded to, and that extension of I-72 to Cameron still has not happened.)
Anyway, back to the topic of the thread: the two examples that I mentioned from Missouri are instances of a phenomenon where the exit numbers on an interstate start from a seemingly arbitrary, non-zero point, because the state DOT wants the exit numbers to reflect their plans to extend the freeway south or west to a given point sometime in the future (plans which, mind you, may not necessarily become reality). What other examples might there be of this taking place, of interstate exit numbers starting from some high point to reflect the DOT's aspirational goals? I'm sure there are several from around the country - I'm looking forward to hearing more.
The first exit on I-2 in south Texas is 130, numbered as if 2 extended all the way up to Laredo.
I-369 in Texarkana, TX recently received exit numbers in the low 100s in anticipation for its eventual southern extension to Future I-69 in Tenaha.
I-87 in North Carolina seems to fit here.
Quote from: The Nature Boy on August 15, 2020, 11:58:30 PM
I-87 in North Carolina seems to fit here.
Since its the southern terminus and the exits start at 1 and increase, I wouldn't necessarily count it. It's not, for instance, signed with high numbers for a conceptual western / southern extension with lower numbers.
Another for North Carolina that would work would be I-73. Exits starting in the 20s in anticipation for its eventual southern extension to the South Carolina state line, part of which currently under construction near Rockingham.
I-295 in Fayetteville start in the 20s in anticipation for its eventual southern / western extension back around to I-95 South, part of which is currently under construction.
Quote from: sprjus4 on August 16, 2020, 12:01:06 AM
Quote from: The Nature Boy on August 15, 2020, 11:58:30 PM
I-87 in North Carolina seems to fit here.
Since its the southern terminus and the exits start at 1 and increase, I wouldn't necessarily count it. It's not, for instance, signed with high numbers for a conceptual western / southern extension with lower numbers.
Another for North Carolina that would work would be I-73. Exits starting in the 20s in anticipation for its eventual southern extension to the South Carolina state line, part of which currently under construction near Rockingham.
Fair point. I was thinking of when they ditched US 64's numbering for I-87, which was assumedly with its future expansion in mind. But that may be outside the scope of this thread.
The first exit on the CA-65 Freeway in Roseville / Rocklin is 307, thinking its going to connect to the section west of Visalia.
Loop 303 in the Phoenix, AZ area fits the bill here.
It's first exit number is 103 in anticipation of a southward expansion.
CT 11. Its lowest numbered "exit" is 4, which is the end of the built highway, and has been for the last 48 years. CTDOT still logs for mileage purposes (and the few MP that exist that haven't fallen into disrepair also show) as if it is still going to be built to I-95 :-D
IL 390/Elgin-O'Hare Tollway. Last numbered exit is Exit 7A/B for IL 19/Irving Park Rd and Gary Ave. The current termination at US 20/Lake Street is unnumbered at MM 6.25.
I believe 6 more miles gets the highway to the existing US 20 Freeway in Elgin, which is the "Zero" point
Quote from: jp the roadgeek on August 16, 2020, 09:11:57 PM
CT 11. Its lowest numbered "exit" is 4, which is the end of the built highway, and has been for the last 48 years. CTDOT still logs for mileage purposes (and the few MP that exist that haven't fallen into disrepair also show) as if it is still going to be built to I-95 :-D
Yep, they even log some points in the proposed section at milepoints 2.35, 4.97, and 7.59.
(https://i.imgur.com/keU00Hk.png)
When INDOT opened I-69 between Evansville and Crane a few years ago, they renumbered the old road north of Indianapolis by adding 200 to every mile marker and exit number. It was just an approximation of what may be the actually mileage of the route when it is finished north from Crane to Indy.
NJ-18's lowest numbered exit is 6, calibrated for a proposed southern extension years ago.
Also, before the Sagamore rotary was converted, there was no MA-3 "Exit 1" signed, which suggested for decades (since the 1976 exit renumbering) that the conversion was coming.
Similar in NJ, Route 55 starts at MP 20, and its lowest exit number is Exit 21.
I-526 starts at US 17 west of Charleston with what would be Exit 10 (no exit number posted, next exit at SC 461 is exit 11).
SC 30's exits are numbered going westward from 1 to (unsigned) 3 at SC 171 with the intention of the 7 miles in between being built.
For years, the southernmost exit of the Pennyrile Parkway at Alternate US 41 was Exit 7. The exit was numbered in anticipation of the parkway's eventual extension to I-24.
MA-128 in Gloucester, starting at exit 12 in reality, but apparently 2 rotaries and 2 traffic signals before it mark exits 8-11 though none are signed that way. Apparently 1-7 would somehow exist if it started further northeast in Rockport.
Quote from: KCRoadFan on August 15, 2020, 11:51:11 PM
Sorry for what looks like a confusing thread title - I couldn't think of a better way to phrase it. You'll probably pick up on what I mean once I explain it a little more.
Anyway, I was just thinking back to some family trips from a while ago. Back in the early aughts, whenever we drove from Columbia, MO (where I lived at the time) to St. Louis, one thing I remember was that back then, US 40/61 through St. Charles County (between the I-70 junction at Wentzville and the Daniel Boone Bridge) still had a lot of traffic lights and at-grade intersections, and it didn't become I-64 until after crossing the bridge into Chesterfield. For a while, heading eastbound, the first numbered exit was Exit 17 at Boone's Crossing; at the time, I had come to realize that the exits were numbered in anticipation of I-64 being extended west to meet I-70 at Wentzville - which, sometime around 2007-08 (I believe), it was.
That brings me to another example from Missouri - namely, when we were headed home from a trip to Madison, WI, in 2006, we drove west on I-72 through Illinois and crossed into Missouri at Hannibal. As I recall, the first exit after the bridge (on the Hannibal bypass) was marked as Exit 157, but soon after that, I-72 ended and the road continued west as US 36 with no additional numbered exits. Feeling curious, sometime after we got home I went into Microsoft Streets & Trips (anyone remember that software?) and traced west 157 miles on US 36 from Hannibal. That brought me to the junction with I-35 at Cameron, which suggests to me that MoDOT had plans to extend the I-72 designation west to that point; I'm not sure if such a plan is still on their agenda. (I would say most likely not; next June will mark 15 years since that trip I alluded to, and that extension of I-72 to Cameron still has not happened.)
Anyway, back to the topic of the thread: the two examples that I mentioned from Missouri are instances of a phenomenon where the exit numbers on an interstate start from a seemingly arbitrary, non-zero point, because the state DOT wants the exit numbers to reflect their plans to extend the freeway south or west to a given point sometime in the future (plans which, mind you, may not necessarily become reality). What other examples might there be of this taking place, of interstate exit numbers starting from some high point to reflect the DOT's aspirational goals? I'm sure there are several from around the country - I'm looking forward to hearing more.
How about out of left field? US-59 in Lufkin has two exits numbered (which is uncommon, but happens in Texas). They pre-date I-69 conversations and count down as you got north. They are exits 391 and 390 telling me that if its based on Texas reference markers, then it is 390 miles from the south side of Lufkin to the top of the panhandle extended (Google maps say its 405 miles and that we me eyeballing it, and if so, that would explain the backwards sequence). Always odd to me that there were other freeway sections to US 59 (including the pre I-69 Houston days) and none got an exit number. Nacogdoches has one if you are traveling southbound you exit 59 to it's self at Exit 59S.
Quote from: SectorZ on August 17, 2020, 03:42:34 PMMA-128 in Gloucester, starting at exit 12 in reality, but apparently 2 rotaries and 2 traffic signals before it mark exits 8-11 though none are signed that way. Apparently 1-7 would somehow exist if it started further northeast in Rockport.
Actually, Exits 9-11 are/were the following:
9 - MA 127A intersection... MA 128's terminus
10 - MA 127 intersection.
Blackburn Circle was never assigned a number.
11 - MA 127/Grant Circle.
Such existed since 1962. 128's original numbering had Grant Circle marked as Exit 1 and the numbers increased southwestward. The fore-mentioned rotaries & intersections originally had no numbers. The
supposed reasoning for the number changes circa 1962 was based on a long-since-aborted (& ill-advised IMHO) proposal to extend 128 into Rockport. For the most part, the existing numbered interchanges (until the MA 1A cloverleaf in Beverly) were simply increased by
10 for simplicity.
That said, any extension of MA 128 into Rockport would
not translate into 8 additional interchanges being built. The area's too small to support such.
The very western end of I-90 is very close to a Mile 2 marker (https://goo.gl/maps/wTRrNPxK7Z6DXYJF9). At one point, a freeway was planned to intersect with the Alaskan Way Viaduct, but it never happened. This helps explain why the interchange of 90 and 405 is 90's Exit 10 and 405's Exit 11, even though 405 starts on I-5 and runs north for a while and 90 is supposed to start very close to I-5 and goes almost straight east.
For I-380 in California, the lowest exit number is 5 (at I-280), since on paper the highway extends to CA-1 near Pacifica.
I can think of at least a couple of California highways where the postmiles (and therefore callbox numbers, if used) reflect proposed routings, but generally when they got around to posting exit numbers they used the constructed highway endpoint. A good example is CA-14.
Quote from: theline on August 17, 2020, 01:41:39 AM
When INDOT opened I-69 between Evansville and Crane a few years ago, they renumbered the old road north of Indianapolis by adding 200 to every mile marker and exit number. It was just an approximation of what may be the actually mileage of the route when it is finished north from Crane to Indy.
I was considering mentioning that, but by the time that renumbering happened, the rest of I-69 was beyond the aspirational stage.
the north end of the nj turnpike/I 95 mileage is based on the original I 95 proposal that went through/around trenton.
Quote from: ztonyg on August 16, 2020, 08:51:23 PM
Loop 303 in the Phoenix, AZ area fits the bill here.
It's first exit number is 103 in anticipation of a southward expansion.
I looked at the map. Where would it be expanded 103 miles
to, exactly?
I-10 in Tucson? Highway 2 in northern Mexico? Somehow, I doubt that.
Here's one. Ontario 401 used to start @ it's exit numbering @ 13 so that they could extend it to a bridge crossing in the future (which is happening right now).
The NY 27 expressway on Long Island starts at Exit 57 or something like that. Someone in the New York thread explained the reasoning but I don't remember it off the top of my head.
The Southern State Parkway begins at Exit 13 because it was a continutation of the Cross Island's exit numbering. Back then, Exit 1 was at the Whitestone Bridge and increased as you went south. I have an old map that shows this
I-90 starts in Seattle at Exit 2A/B. Because the original terminus was supposed to be US 99/SR 99 on the Alaskan Way Viaduct.
CA 241 starts with exit 14 at Oso Parkway under the presumption there would be an eventual extension to I-5. The extension was killed.
CA 91 starts with exit 6 (Harbor Fwy) even though at the time exit numbering was implemented, the westernmost 6 miles had been deleted from the books. The numbering comports with the county post mile designations.
CA 170 starts with exit 5 (Ventura Fwy) even though at the time exit numbering was implemented, the southernmost 5 miles had been deleted from the books. This is to conform with state mile post designations for this section. The county post mile designations are even higher, still reflecting a planned end for the route at LAX.
this has been long since made correct..
but before they extended i-76 to i-70 in denver, its last exit was the junction with i-25, and was signed exit 6.
Quote from: TEG24601 on August 23, 2020, 11:15:32 AM
I-90 starts in Seattle at Exit 2A/B. Because the original terminus was supposed to be US 99/SR 99 on the Alaskan Way Viaduct.
The weird thing being that the Alaskan Way is far closer than 2 miles from I-90's start point. Was it supposed to take over the Alaskan Way for a short distance?
Quote from: DJ Particle on August 24, 2020, 02:22:36 AM
Quote from: TEG24601 on August 23, 2020, 11:15:32 AM
I-90 starts in Seattle at Exit 2A/B. Because the original terminus was supposed to be US 99/SR 99 on the Alaskan Way Viaduct.
The weird thing being that the Alaskan Way is far closer than 2 miles from I-90's start point. Was it supposed to take over the Alaskan Way for a short distance?
Probably not. Within a mile is Colman Dock, and 2 miles is the Spokane Street Viaduct.
Where might the additional two miles have gone, then?
Quote from: Bruce on August 24, 2020, 02:30:22 AM
Quote from: DJ Particle on August 24, 2020, 02:22:36 AM
Quote from: TEG24601 on August 23, 2020, 11:15:32 AM
I-90 starts in Seattle at Exit 2A/B. Because the original terminus was supposed to be US 99/SR 99 on the Alaskan Way Viaduct.
The weird thing being that the Alaskan Way is far closer than 2 miles from I-90's start point. Was it supposed to take over the Alaskan Way for a short distance?
Probably not. Within a mile is Colman Dock, and 2 miles is the Spokane Street Viaduct.
I-5 to SR-99 is only 1/2 mile. Where is the additional 1.5 miles?
Sequential exit numbering maybe?
Not a starting point, but based on the mile markers and exit numbers posted on its east-west freeway section in Farmington Hills and Farmington, the terminus of M-5 at Pontiac Trail in Commerce Township would be about mile 6.9, not mile 0. Continuing north (actually slightly to the northwest) from there would put mile 0 at a junction with M-59 on the west side of Oxbow Lake.