US75 exit numbers: *Huh?*

[yakra]

This old thread from 2012 does a good job of explaining how US54 in El Paso and US59 got their exit numbers. Even explains US82 in Grayson & Fannin counties to my satisfaction.

Then, we have US190, with new exit numbers going up on the I-14 overlap. The exit numbers reflect the start of US190 rather than some random-ass point in New Mexico, although they're still off by about 4. OK, fair play. At least it's kinda MUTCD compliant.

But what's the story with US75?  We start off on I-345, continuing I-45's numbering scheme. Sure, whatever. Then, Exits 1 thru 8 (with some alphabet soup thrown in). Then, at MP 10, exit numbers jump ahead to Exit 20. The sequence here on out is sequential (note the 3-mile gaps Exit 51-52-53), and has had some reconfigurations over the years that could explain its own alphabet soup.

US 75 of course does not follow the grid, but its numbers are the only remnant of pre-Interstate exit numbering (which was also used on US 59 north and US 75 south in Houston).

OK, makes sense. If I count down from 20, that could put Exit 1 near the old US175 split, which is where the freeway began once upon a time.

But whats the deal with Exits 1 thru 8, and then skipping ahead 12 exits?
Exits 1&2 @ miles 2&3 give way to exits 4-6 @ miles 6-10, so maybe we could consider it mileage-based with some "slop"... Could this be part of at attempt to convert to mileage-based exits that was aborted or just forgotten about?
What's the story?

[The Ghostbuster]

I can answer that. The exits north of Interstate 635 are the original sequential exit numbers of the US 75 freeway. The exits south of 635 also were originally sequential, but after a reconstruction and widening of the US 75 freeway (as well as reducing the number of exit and entrance ramps), the exit numbers south of 635 became mileage-based. If you ask me, the exits north of 635 should have been converted to mileage-based as well.

[abqtraveler]

I can answer that. The exits north of Interstate 635 are the original sequential exit numbers of the US 75 freeway. The exits south of 635 also were originally sequential, but after a reconstruction and widening of the US 75 freeway (as well as reducing the number of exit and entrance ramps), the exit numbers south of 635 became mileage-based. If you ask me, the exits north of 635 should have been converted to mileage-based as well.

The sequential exit numbers on US-75 were left behind when Texas converted from sequential numbering to mileage-based numbering in the 1970s.

[-- US 175 --]

And after all that, when/if I-45 can get extended north, all the exits will have to be renumbered (and new, corresponding MMs will have to be placed).

[abqtraveler]

And after all that, when/if I-45 can get extended north, all the exits will have to be renumbered (and new, corresponding MMs will have to be placed).

The biggest obstacles to getting I-45 extended north are: 1) connecting it to something in Oklahoma, and 2) getting the idea of dismantling I-345 through downtown Dallas out of people's minds. For the latter, if the removal of the I-345 freeway does happen, forget about ever extending I-45 north of where it ends today.

[Road Hog]

Give it another 3 to 4 years once the US 75 project in Sherman is finished and Oklahoma finishes its upgrade through Calera. By then we might get an I-45 designation up to US 70 in Durant. If that happens first, tearing down 345 is completely off the table (it basically already is, as long as Eric Johnson is Dallas mayor.)

[rte66man]

Give it another 3 to 4 years once the US 75 project in Sherman is finished and Oklahoma finishes its upgrade through Calera. By then we might get an I-45 designation up to US 70 in Durant. If that happens first, tearing down 345 is completely off the table (it basically already is, as long as Eric Johnson is Dallas mayor.)

Not quite. Oklahoma still has to eliminate at least 9 at-grade access points from the southern end of the Calera project to the OK91 interchange. ROW for that stretch is on the 8 Year plan so there is still hope.

[sparker]

And after all that, when/if I-45 can get extended north, all the exits will have to be renumbered (and new, corresponding MMs will have to be placed).

The biggest obstacles to getting I-45 extended north are: 1) connecting it to something in Oklahoma, and 2) getting the idea of dismantling I-345 through downtown Dallas out of people's minds. For the latter, if the removal of the I-345 freeway does happen, forget about ever extending I-45 north of where it ends today.

That just might be one of those "chicken or egg" circumstances.  If a I-45 northern extension, which would naturally subsume I-345, was formally initiated, the chances are that talk of 345 removal would be largely rendered moot (although some urban absolutists may well persist up to and past the I-45 signage point!).  But the fact that the mayor opposes the teardown does buy a significant amount of time -- perhaps enough for OK to finalize plans at least as far north as the US 70 junction.  As a designated "stub", I-345 will always be a target -- but as the "8664" activity in Louisville has demonstrated, severing a trunk route is a magnitude more difficult. 

[The Ghostbuster]

I highly doubt Interstate 45 will ever be extended (although I wouldn't oppose extending it). I would strongly oppose tearing down Interstate 345, though. It seems to me like a needed link in the city's freeway and tollway network.

[sparker]

I highly doubt Interstate 45 will ever be extended (although I wouldn't oppose extending it). I would strongly oppose tearing down Interstate 345, though. It seems to me like a needed link in the city's freeway and tollway network.

If TxDOT can find it within themselves to request signage for 26 miles of I-14, based on supporting a new corridor (HPC #84) that abruptly ends at the LA state line -- and is also willing to request signage for the Rio Grande Valley (currently) isolated Interstate cluster, then a simple I-45 extension over a facility brought up to standards would not only be not out of the question but a reasonably likely occurrence, given the development along US 75 from Dallas north to Sherman and the state line.  Of course, ODOT would have some involvement just to get the corridor to some sort of traffic generator.  Naturally, it would be hoped that the "generator" of choice would be at least I-40; but US 70 at Durant would probably have to do in the meantime.  But that might provoke TxDOT to make a case to ODOT to expedite whatever upgrades are necessary to make that happen.  It might even include an entreaty such as:

https://www.bing.com/videos/search?q=caddyshack+well+we're+waiting&docid=60805562313132710373&mid=28939079C54FE701E62E28939079C54FE701E62E&view=detail&FORM=VIRE 

[motorola870]

I highly doubt Interstate 45 will ever be extended (although I wouldn't oppose extending it). I would strongly oppose tearing down Interstate 345, though. It seems to me like a needed link in the city's freeway and tollway network.

Its already in the works Sherman area is being upgraded to interstate standards. Sherman and Denison are pushing for interstate classification on US75. The work in that area is to be completed in the next year or two I believe. To be honest the logical endpoint of I45 would either be the US69 split or at US82 interchange until Oklahoma is ready to bring it across the border.

[Road Hog]

I highly doubt Interstate 45 will ever be extended (although I wouldn't oppose extending it). I would strongly oppose tearing down Interstate 345, though. It seems to me like a needed link in the city's freeway and tollway network.

Its already in the works Sherman area is being upgraded to interstate standards. Sherman and Denison are pushing for interstate classification on US75. The work in that area is to be completed in the next year or two I believe. To be honest the logical endpoint of I45 would either be the US69 split or at US82 interchange until Oklahoma is ready to bring it across the border.

The substandard volleyball at US75 and US 82 is part of the project, and the freeway north of there through Denison is newer and more to standard. I-45 could easily be extended to the north US69 interchange, which is practically at the foot of the Red River bridge.

[I-35]

I highly doubt Interstate 45 will ever be extended (although I wouldn't oppose extending it). I would strongly oppose tearing down Interstate 345, though. It seems to me like a needed link in the city's freeway and tollway network.

Its already in the works Sherman area is being upgraded to interstate standards. Sherman and Denison are pushing for interstate classification on US75. The work in that area is to be completed in the next year or two I believe. To be honest the logical endpoint of I45 would either be the US69 split or at US82 interchange until Oklahoma is ready to bring it across the border.

The substandard volleyball at US75 and US 82 is part of the project, and the freeway north of there through Denison is newer and more to standard. I-45 could easily be extended to the north US69 interchange, which is practically at the foot of the Red River bridge.

Wasn't TxDOT's 'fix' for the volleyball just to add lanes to the frontage roads and dual lefts throughout?  Don't recall seeing flyovers or stacks being added, unfortunately.

[bwana39]

I-345? Why is it 345? Why was it not made into I-45 when it was constructed?

The idea was the initial freeway miles for I-45 were to IH-30. US-75 was already freeway north of downtown. There were ideas that I-45 would NOT follow US-75 past downtown. I have heard all of my life that I-45 was planned to follow SH-114 to US-287 to Amarillo. 

Anyway there was INTERSTATE money available. Available for interstates ONLY. So to bridge the freeway gap between I-45 at I-30 to the freeway portion of North Central Expressway (US-75), they built the unsigned I-345.  Recently the urbanists have seized on that differentiation to use it as a mantra to tear it down. 

The idea to extend I-45 to Oklahoma is fairly recent. So I understand  Collin County is one of the four or 5 most populous counties in the US without an Interstate Highway.  (I-30 misses it by a couple of miles at Royse City). It does have lots of tollway miles and US-75, just not a numbered Interstate.

[sparker]

I highly doubt Interstate 45 will ever be extended (although I wouldn't oppose extending it). I would strongly oppose tearing down Interstate 345, though. It seems to me like a needed link in the city's freeway and tollway network.

Its already in the works Sherman area is being upgraded to interstate standards. Sherman and Denison are pushing for interstate classification on US75. The work in that area is to be completed in the next year or two I believe. To be honest the logical endpoint of I45 would either be the US69 split or at US82 interchange until Oklahoma is ready to bring it across the border.

The substandard volleyball at US75 and US 82 is part of the project, and the freeway north of there through Denison is newer and more to standard. I-45 could easily be extended to the north US69 interchange, which is practically at the foot of the Red River bridge.

Wasn't TxDOT's 'fix' for the volleyball just to add lanes to the frontage roads and dual lefts throughout?  Don't recall seeing flyovers or stacks being added, unfortunately.

Since US 82 in either direction from US 75 is a mixed facility -- some freeway, some conventional divided highway, and some TX-style "frontage road" segments, it was probably calculated that there was no pressing need to upgrade to a stack, since the presence of volleyball-configured frontage roads functionally precludes free-flow loops unless fully elevated (in which case a stack would likely be considered preferable).  A simple guess:  unless there were near-term plans in the works to expand US 82 into a full freeway for a significant distance from the US 75 interchange, upgrading the present volleyball to a free-flow interchange won't happen regardless of whether US 75's designation stays the same or I-45 is extended north.

I-345? Why is it 345? Why was it not made into I-45 when it was constructed?

The idea was the initial freeway miles for I-45 were to IH-30. US-75 was already freeway north of downtown. There were ideas that I-45 would NOT follow US-75 past downtown. I have heard all of my life that I-45 was planned to follow SH-114 to US-287 to Amarillo. 

Anyway there was INTERSTATE money available. Available for interstates ONLY. So to bridge the freeway gap between I-45 at I-30 to the freeway portion of North Central Expressway (US-75), they built the unsigned I-345.  Recently the urbanists have seized on that differentiation to use it as a mantra to tear it down. 

The idea to extend I-45 to Oklahoma is fairly recent. So I understand  Collin County is one of the four or 5 most populous counties in the US without an Interstate Highway.  (I-30 misses it by a couple of miles at Royse City). It does have lots of tollway miles and US-75, just not a numbered Interstate.

There has been considerable speculation over the years that I-45 would veer northwest over US 287, but AFAIK nothing official to that effect has ever been proposed (actually, this forum probably has hosted much of that speculation!).  As for the I-345 designation, apparently TxDOT wanted to have Interstate funds available for their downtown viaduct -- and it was during the period that some stub extensions were initially designated as spurs (cf. I-79/179 at Erie, PA), so the present formal/unsigned designation came about.  But unfortunately teardown advocates have seized upon that difference to claim that the segment is not only troublesome (at least to their goals) but an unnecessary "add-on" to the original Interstate network.  Perhaps a trunk extension of I-45 northward to Sherman/Denison would have the effect of quelling a portion of the uproar, since what was I-345 is now necessary to maintain continuity of the trunk Interstate 45.  Of course, the "usual suspects" who piss & moan about Interstate expansion in general will likely characterize such action as gratuitous and, again, unnecessary; that's to be expected.  But it would likely garner the support of much of North Texas; how it is received north of the state line is yet TBD! 

[I-35]

Flame away.  345 being there or not being there doesn't really preclude an extension of 45.  I'm a big fan of tunneling 345, but that is mind-bogglingly expensive, plus would need extensive coordination with the existing and D2 tunnels for DART.

[sparker]

Flame away.  345 being there or not being there doesn't really preclude an extension of 45.  I'm a big fan of tunneling 345, but that is mind-bogglingly expensive, plus would need extensive coordination with the existing and D2 tunnels for DART.

OK, here's the process as it would occur -- a TX congressperson would introduce legislation to extend I-45 to at least the OK state line; this would include a designation change for the section that's now I-345.  When passed (these things are usually appended to other transportation outlay bills, so without objection from within Congress, they sail through on a regular basis), it's then up to FHWA to vet the facility to make sure it's up to standards.  Chances are there will be a bit of back-and-forth in this case due to a state line not being an actual traffic generator (like US 70 in OK), but if reassurances from OK that they have the projects as far north as Durant "in the hopper" (via whatever form ODOT utilizes as project programming), then "future I-45" signage can be erected north of the Red River.   When all that happens, the "TO I-45" SB and "TO US 75" signage on current I-345 comes down and is replaced with I-45 shields.  What is depicted as the I-45 reroute red line on the above map is very unlikely to occur except as a detour in the event that current I-345 is reconfigured in such a way that temporary closure is required. 

[ethanhopkin14]

Make US-75 from the Red River to downtown Dallas and extension of I-345.

Any sequentially numbered interstate needs a real life presence. 

[bwana39]

There is not enough room along the other three sides of downtown in Dallas to do what they are probably going to do in Houston. I-45 in Houston was the narrower of the ROW's. You might could expand I-30 to the south. You MIGHT could expand the Mixmaster a little. You could not expand Woodall Rogers Freeway AT all. Traffic counts  are in excess of 180,000 vehicles per day on I-345.

While it may not be numbered as INTERSTATE-X, Central Expressway is a major freeway.  I-35 at Valley View has average traffic counts around 42,000 vehicles per day. This is AFTER the confluence of I-35E & I-35W. US-75 at Howe has around 45,000 cars vehicles per day. I-35 is an interstate highway that continues as freeway indefinitely.  US-75 while still a freeway around 20 miles further north. 75 is fed by the SRT (SH-121) but it is only supported further north by the Oklahoma Portion of US-69 which is a marginally improved arterial.

Do not let anyone tell you that traffic will not be dramatically impacted. I agree that traffic will adapt. That does not mean that parts or all of the traffic that uses this road now will not be significantly impacted by longer commute / transit times, greater impacts for the roads that people choose to substitute. DFW is still growing.  While it looks like the urbanists are leading the push for this. The money is in the hands of the people who own / control  Deep Ellum. If that freeway is gone, the thought is that there can be skyscraper development. It is kind of like creating new land.

Since 345 was built elevated to allow smooth traffic between downtown and the areas to the east, the traffic flows well. The freeway does not form a physical barrier. There are, however, emotional barriers. This is a mix of a clearly delineated end to the existing downtown coupled with the traditional use of the property east of this line (or more aptly the railroad line that was there even earlier.). South of Ross and east of I-345 continues to be ethnically segregated. While it appears it was mostly black back when, it is predominately Hispanic now.

Deep Ellum is a bunch of mid-century utilitarian buildings. Some go back before the depression. There is really nothing special about it. Some place in the eighties night club operators went there because of cheap rents and tolerance of loudness. At a later point, someone wanted to convert it to an "entertainment district". That has had mixed results over the past 30 years more or less.  In 1990, the "West End" was the place to go. Today there are few restaurants and virtually zero other entertainment options. The simple fact is in Texas, entertainment districts change.

There is the opinion that Deep Ellum isn't safe.  If you assume the homeless are the instigators of the petty crime in Deep Ellum, getting rid of the elevated freeway MIGHT help.  At best, it would shift the homeless populations elsewhere.  Getting rid of a freeway or even all freeways is not the cure for homelessness. 

They say the freeway destroyed the neighborhood in the area.  Most of the neighborhood that was disturbed in that area was done by I-30 not 345. The numbered streets (1st, 2nd. is and was the division between commercial and residential.  Interstate 30 MAY have marginalized Fair Park. On the other hand, time may have been as much of the problem as the deteriorating neighborhood. 

If you dig deep property owners east of I-345 have a far greater stake in this than the urbanists. 

FINALLY, as a Texan,  I am surely not a fan of ANY 3DI. If it is numbered as an interstate it should be 45. I can tell you for sure, the I-345 will not have any particular relevance versus US-75. For it to make any empathetic impact it would need to be a FULL Interstate IE a 2digit number. The Spur designation honestly could still let this absurd map come true.

[ethanhopkin14]

Back to the poster's original question, I am so glad you asked this question on this forum.  I had similar questions when I was a kid about US-75 (why does this US highway have exit numbers when other non-interstate freeways in the state don't?) but of course there was no internet then so I had to "make up" answers to move on (usually they are "just because").  Then when the Central Expressway project was finally completed after 678 years of construction, I noticed the gap in exit numbers, and asked the same question, just to go back to the old standby of "just because".  It was many years later and because of the internet I learned of US-75 havening, because of a holdover, sequential exit numbers, and the section from I-345 to I-635 had many exits removed. 

This is all a side note:  being a Texan, and not leaving the state save from a yearly trip to Shreveport from my grandparents house and back, I thought all roads in the country were like Texas.  Interstate highways had mile markers and numbered exits (and exit gore signs with the numbers as a tab above) and non-interstate had neither (it was a very long time before I learned about the Texas reference mile system mainly because the reference mile signs are so small and innocuous).  Then I saw Central Expressway and I was baffled.  Little did I know that most states mile post all their highways and having exit numbers on non-interstate freeways was no big deal (plus the horror I had when I saw exit numbers placed on the gore signs!). 

I love oddities like that.  I think the internet is also the single greatest and worst thing we have ever created, but having this forum where you can ask these questions is when I think its a wonderful thing. 

[roadman65]

Well the cyberworld is good and bad at the same time.  The GPS is good when its an aide, but for relying on it to find places and forgetting how to navigate originally is bad for focus on the roads.  The same for the web here.

Yes we can find answers at the touch and yet it is bad for us as it has its bad things.  Also we talk more to people that we never spoke to before which is bad because that is how we get upset over news and gossip and probably why this last election was so different than the previous ones because of the things we now have.

Anyway, back on topic.  Exit numbers are not only unusual in Texas, but here in Florida as the original Turnpike numbering scheme was out of wack.  It skipped 4 numbers south of Fort Pierce to the original mainline end in Golden Glades, and then in Central Florida every number was a multiple of five ending in zero or five.  Then they went mileage based and eliminated that including adding numbers to the HEFT which never had numbers prior to.  The original mainline to Golden Glades uses the X suffix to its two interchanges it has.

Then I-895 had the oddest scheme in MD.  It started with 18 at its southern end and counted down to 11  just south of the Tunnel and then 1 to 4 north of the tunnel.  However because the Harbor Tunnel Thruway had partial interchanges and going north the first exit was 1 and going the other way it was 11 the numbers never got confusing. 

Then the JFK Highway was odd as it left out Exit 1 and started with 2 at the former DDI interchange at I-695.  However, that was because the transition from the JFK to the Tunnel Thruway was Exit 1, though not signed.  If Moravia Road had a Exit 1 tab, it would have made sense then, but now the mile based numbers rule MD to end all that confusion.