Longest state lines with no interstate crossings

[webny99]

I was just noticing that from the start of the NY/VT state line at Rouses Point, you have to go south all the way to I-90 before you encounter an interstate that crosses the state line. There are no interstate crossings between NY and VT. The distance from Rouses Point to I-90 at the NY/MA line is around 200 miles.

So, two questions:

1. What is the longest shared state line with no interstate crossings? NY/VT would be a candidate, but WI/MI and NE/KS are longer.

2. What is the longest combined stretch of state lines with no interstate crossings?
-As in the example above, you could continue NY/VT with NY/MA, but you have to stop when you hit an interstate.
-Both of the original states can switch as long as the line is continuous, such as ND/MT > MT/SD > SD/WY
-90 degree turns, such as the corner of WY near Yellowstone, are allowed, but 180 degree turns are not allowed (I'm not sure if any even exist, so this is just a pre-emptive note).
-Also consider that partial state lines with a long section between interstates (like TX/NM, which does not qualify for question 1 because of I-10 and I-27) could still count.

Edited to add:

An interesting question 3 might be, for each state, what is the longest stretch of state line between crossings? i.e. measuring from one Interstate to the next along that state's boundaries.

Obviously, all questions pertain only to the lower 48 states.

[TheHighwayMan3561]

Unscientifically I think NE/SD is longer than NE/KS, so that's my guess.

[SkyPesos]

I was just noticing that from the start of the NY/VT state line at Rouses Point, you have to go south all the way to I-90 before you encounter an interstate that crosses the state line. There are no interstate crossings between NY and VT. The distance from Rouses Point to I-90 at the NY/MA line is around 200 miles.

So, two questions:

1. What is the longest shared state line with no interstate crossings? NY/VT would be a candidate, but WI/MI and NE/KS are longer.

2. What is the longest combined stretch of state lines with no interstate crossings?
-As in the example above, you could continue NY/VT with NY/MA, but you have to stop when you hit an interstate.
-Both of the original states can switch as long as the line is continuous, such as ND/MT > MT/SD > SD/WY
-90 degree turns, such as the corner of WY near Yellowstone, are allowed, but 180 degree turns are not allowed (I'm not sure if any even exist, so this is just a pre-emptive note).
-Also consider that partial state lines with a long section between interstates (like TX/NM, which does not qualify for question 1 because of I-10 and I-27) could still count.

Obviously, both questions pertain only to the lower 48 states.

This is my nomination for #2:

[webny99]

^ That crosses I-535, but still a good candidate even starting in Duluth.

[SkyPesos]

^ That crosses I-535, but still a good candidate even starting in Duluth.

Times I forgot I-535 exists: too many to count 
Modified it without the section between I-94 and I-535:


And the Wisconsin-Michigan border for #1:

[US 89]

Looking at a handful of western states with long borders, the biggest ones I see without an interstate crossing are NV-OR, NV-ID, and ID-WY.

[Scott5114]

An interesting question 3 might be, for each state, what is the longest stretch of state line between crossings? i.e. measuring from one Interstate to the next along that state's boundaries.

[SkyPesos]

An interesting question 3 might be, for each state, what is the longest stretch of state line between crossings? i.e. measuring from one Interstate to the next along that state's boundaries.

Ohio: about 250 miles along its border with KY and WV between I-275 and I-77.

Indiana: about 250 miles along its border with IL and KY between both I-64 crossings. This will get shortened when I-69's Ohio River crossing gets finished.

Kentucky: about 280 miles along its border with IL and IN between I-24 and I-64. This will get shortened when I-69's Ohio River crossing gets finished.

Missouri: about 350 miles along its border with OK and AR between I-44 and I-55. This will get shortened when I-49's Bella Vista Bypass gets finished.

Illinois: about 165 miles along its border with IA and WI between I-80 and I-39. Illinois have two others that are close in length.
- Between I-72 and I-280: 160 miles
- Between I-57 and I-255: 160 miles

[jp the roadgeek]

The only other one I could think of in the Northeast is NY-RI, and that's an extremely small water border.  VA and KY have a significant border with no interstate crossings.  GA and NC have a smaller one.

[Ga293]

An interesting question 3 might be, for each state, what is the longest stretch of state line between crossings? i.e. measuring from one Interstate to the next along that state's boundaries.

The TX/NM border runs for right around 425 miles between I-10 and I-40. A fairly coarse estimate of the ID/MT border between I-90 and I-15 pegs it around 405 miles, but a more meticulous, detailed measurement should yield a distance significantly longer than the section of the TX/NM border.

[Road Hog]

Arkansas and Mississippi have no interstate crossings. Because the border follows the twists and turns of the Mississippi River, it will be quite lengthy, probably close to 400 miles.

[Scott5114]

Arkansas and Mississippi have no interstate crossings. Because the border follows the twists and turns of the Mississippi River, it will be quite lengthy, probably close to 400 miles.

Fortunately, the Mississippi River is mileposted. The southern border of Arkansas intersects the river at mile 507, and the southern border of Tennessee intersects at mile 715, for a total of 208 miles.

There are a few places where the border meanders along oxbows while the river doesnt, but it's definitely not 200 miles worth.

[debragga]

Arkansas and Mississippi have no interstate crossings. Because the border follows the twists and turns of the Mississippi River, it will be quite lengthy, probably close to 400 miles.

You can add the Louisiana-Arkansas state line east of I-49 as well, since it's all contiguous.

[hbelkins]

Kentucky: about 280 miles along its border with IL and IN between I-24 and I-64. This will get shortened when I-69's Ohio River crossing gets finished.

That certainly highlights the meanderings of the Ohio River, as it's definitely not 280 miles from Louisville to Paducah via US 60.

[JayhawkCO]

For question #2 not using maritime borders:

Around 502 miles along the CA/OR -> NV/OR -> NV/ID -> ID/UT border from I-5 to I-84.

Around 544 miles along the NE/WY -> NE/SD -> NE/IA border from I-80 to I-129.

Around 570 miles along WY/MT -> MT/SD -> SD/ND border from I-90 to I-29.

Chris

[Henry]

CA has two of these: first on the border with NV between I-15 and I-80, and then from there to the OR border where I-5 crosses over.

WA has a fairly large gap as well, stretching from I-90 on the ID border to I-82 on the OR border with the Columbia River.

For OR, it has two as well: from I-82 on the WA border to I-84 on the ID border, and then from there to I-5 at the CA border, which includes the aforementioned border with NV.

[US 89]

Question #2 for Utah is about 406 miles, from I-15 at the AZ border to I-70 at the CO border.

[MCRoads]

The Oklahoma panhandle might be a contender, as no interstate crosses into Oklahoma from I-40, up north, west around the panhandle, and east until I-35. According to rough measurements, it is 600 miles. I believe this may be a candidate for the longest such land border.

[webny99]

The Oklahoma panhandle might be a contender, as no interstate crosses into Oklahoma from I-40, up north, west around the panhandle, and east until I-35. According to rough measurements, it is 600 miles. I believe this may be a candidate for the longest such land border.

↓ I knew I put this in there for a reason!   But now that we have a practical example, I'm wavering. I'll let the audience decide if it counts or not.

2. What is the longest combined stretch of state lines with no interstate crossings?
...
-90 degree turns, such as the corner of WY near Yellowstone, are allowed, but 180 degree turns are not allowed (I'm not sure if any even exist, so this is just a pre-emptive note).

[MCRoads]

Keep in mind that the panhandle itself is pretty wide, about 35 miles IIRC.

[ran4sh]

An interesting question 3 might be, for each state, what is the longest stretch of state line between crossings? i.e. measuring from one Interstate to the next along that state's boundaries.

For Georgia it's the section between I-75 at the FL line and I-85 at the AL line.

For NC I would guess the section from I-40 at the TN line to I-26 at the SC line.

[Flint1979]

I was just noticing that from the start of the NY/VT state line at Rouses Point, you have to go south all the way to I-90 before you encounter an interstate that crosses the state line. There are no interstate crossings between NY and VT. The distance from Rouses Point to I-90 at the NY/MA line is around 200 miles.

So, two questions:

1. What is the longest shared state line with no interstate crossings? NY/VT would be a candidate, but WI/MI and NE/KS are longer.

2. What is the longest combined stretch of state lines with no interstate crossings?
-As in the example above, you could continue NY/VT with NY/MA, but you have to stop when you hit an interstate.
-Both of the original states can switch as long as the line is continuous, such as ND/MT > MT/SD > SD/WY
-90 degree turns, such as the corner of WY near Yellowstone, are allowed, but 180 degree turns are not allowed (I'm not sure if any even exist, so this is just a pre-emptive note).
-Also consider that partial state lines with a long section between interstates (like TX/NM, which does not qualify for question 1 because of I-10 and I-27) could still count.

Obviously, both questions pertain only to the lower 48 states.

This is my nomination for #2:

You went past I-535.

[hotdogPi]

You went past I-535.

Already mentioned in reply #3.

[JayhawkCO]

An interesting question 3 might be, for each state, what is the longest stretch of state line between crossings? i.e. measuring from one Interstate to the next along that state's boundaries.

Looks like about 403 miles for Colorado, from I-70 @ UT to I-25 @ NM.

Chris

[GaryV]

An interesting question 3 might be, for each state, what is the longest stretch of state line between crossings? i.e. measuring from one Interstate to the next along that state's boundaries.

Michigan:  Start at I-94 going into IN.  Continue to and up the middle of Lake Michigan, into Green Bay (the bay, not the city), along the MI/WI land border, up around Isle Royale, over to the St Marys River, down Lake Huron through to Lake Erie, around the corner along the Ohio border and end where I-75 crosses the line.

Montana along its northern borders is probably even longer.