Interstate Parent With Mile Marker for Child

[jp the roadgeek]

The only one I can think of in all of New England is I-95 in Maine with MM 195 in Old Town and MM 295 between Smyrna and Houlton. 

I-87 in NY is another story.  If it went by true mileage, there would be MM 287 a couple miles south of Northway Exit 33.

[JayhawkCO]

Bonus: Closest east of the Mississippi

Vermont:
I-89 would need 59 more miles for MM 189.

For an east of the Mississippi state with a lot of 3di, Florida is pretty close too. Mileposts exist for 110, 175, 195, 275, 295 and 375 on their corresponding parent interstate. 395 is a near miss, as I-95's highest milepost in the state is 382. The only one left after those is 595.

They just need to hurry up and designate I-795 then, as to make my post more accurate. 

Chris

[michravera]

Is California excluded due to it having county mile markers instead of state ones? Cause it has a few on I-5 that come to mind.

I tend to lean toward exit numbering when it comes to California since it closely resembles mile markers.  Plus, I find the post miles confusing.  For instance, even if there isn't an exit 605 on I-5, I say the approximate location of where mile 605 should be based on the surrounding exit numbering is good enough.

California tends to have 3dis in the southern and western parts of the state where the mile markers (and current exit numbers) are the lowest. Several "Exit 1x"s for CASR-1, but nothing else very close.
I suspect that I-5 will be closest with I-105, since it is the lowest numbered 3di will be the closest miss of a parent interstate having a mile marker near one of its children.
In relative terms, the exit to I-505 on I-5 might be nearly as close. I-805 and -905 have exit numbers from I-5 that are less than 30. There is no I-180 and I-80 in California isn't even close to 280 miles long, let alone 380, 580, 680, 780, or 980.
I-15 takes a funny path, so the exit with I-215 may be relatively close.
I-10's exit for I-210 is numbered less than 100 and I-10 doesn't even run anything close to 310 miles inside California, so nothing else would be close.
At the moment, I-40 doesn't have any 3dis in California. I-8 might run 208 miles, but  there is no I-108 or -208.

[ethanhopkin14]

This all came to me because I was thinking about how, despite Texas' size, and that I-20 spends a very long time in Texas, it doesn't have a mile marker 820 to go with it's one child.  Poor thing.  Actually, I-45 and I-35 don't have a mile marker 345 and 635 respectively. 

On the other hand, I-10 in Texas is long enough for MM 410 and MM 610 - and also 810 if such an interstate actually existed in Texas. (Come on, TXDOT, do it - just call the Sam Houston Tollway I-810, to go along with "Beltway 8", and maybe while you're at it, make the Anderson Loop in San Antonio I-210 to match the city's area code!)

Also, I-10 has a Mile Marker 110 in the Sierra Blanca area to correspond with I-110 in El Paso. 

[roadman65]

I mentioned before just how close I-275 in Florida is to MM 275 on I-75. When Exit 275 first opened to traffic in 2001, I thought about it then that if I-75 was only 1 mile shorter it would have been the same route number as exit number.

That would have been the best entry for this thread.

[rower155]

This is a fun game searching for them using this app:

https://apps.apple.com/us/app/mile-1/id1562022453

[rower155]

In MA, I-90 intersects I-290 at MM 90.

In FL, I-75 intersect I-275 about a mile from MM 275.

[akotchi]

For Pennsylvania

I-76 has M.P. 176 and 276.  I-176 is at Exit 298 (120 miles), while I-276 is at Exit 326 (50 miles).  One is within shouting distance. (There is no M.P. 376, 476 or 676)

I-80 has M.P. 180.  I-180 is Exit 212 off of I-80, so at 32 miles away, this is pretty close. (There is no M.P. 380)

On the flip side, I-476 does have a M.P. 76, though I-76 is Exit 16.

I-376 also has a M.P. 76; I-76 is at the eastern end, Exit 85, which is really close.

None of the other 2di's (I-70, I-95, I-79, I-83, I-81, I-90, I-99) are long enough to test.

[zachary_amaryllis]

Both of Colorado's 3dis have one, and they're both pretty close to the child interstate.

I-25 MM 225 is at the exit for 136th Street in Westminster, about 25 miles from its junction with I-225.
I-70 MM 270 is at the exit for Sheridan Boulevard in Wheat Ridge/Lakeside, about 9 miles from its junction with I-270.

Had C-470/E-470 actually gotten an interstate designation, it would miss having one by about 20 miles, but obviously the children would be a long way away.

In Wyoming:
I-80 MM 180 is near Wamsutter, about 180 miles from its junction with I-180, so it's basically at the halfway point.

Chris

beat me to it... though i didn't know the 180 one. nice!

[US 89]

Nevada has none - despite being such a big state, all three of its 3dis are still too big. I-15 only runs 123 miles in the state (not enough to cover 215 or 515), and I-80's impressive 410 miles is still not enough to cover I-580.

[Scott5114]

I-44 in OK intersects I-244 eight miles west of MP 244.

[iowahighways]

Iowa has two: I-29 has mile marker 129 north of Sloan, or about 15 miles from I-129. And I-80 has Exit 280 near Stockton, ten miles west of I-280.

[froggie]

Two states not mentioned yet (and both east of the Mississippi):

I-64 Virginia has MP 264 a mere 20 miles from its interchange with I-264, and coincidentally is at an interchange with another child:  I-664.

I-40 Tennessee has MP 140, MP 240, and MP 440, but all three are significant distances from their corresponding child routes.