How many interstates in the state you live in?

[JayhawkCO]

Just a solid five.  25, 70, 76, 225, 270.

Chris

[wriddle082]

Five 2di's (20, 26, 77, 85, 95)
Six 3di's (520, 126, 526, 185, 385, 585)

So grand total of 11, but there is also one signed business route (85), two signed business spurs (20, 526), and two unsigned business spurs (126, 385).  And one future 2di (73).

[GaryV]

Michigan: total 13; 4 2di's, 9 3di's

69
75
94
96

275
375
475
675
194
196
296 (unsigned)
496
696

[GreenLanternCorps]

Too many, California went way overboard with non-chargeable 3ds.

Let's see if I can remember off the top of my head:

I-5: I-105, I-205, (I-305), I-405, I-505 originally planned as I-5W, I-605, I-805.  FUTURE: 905. 
(future I-7 or whatever Route 99 is planned to be numbered as if that ever is upgraded to Interstate)
I-10: I-110, I-210, I-710
I-15: I-215 formerly known as I-15E
I-40
I-80: I-280, I-380, I-580 (formerly I-5W), I-680, I-780, I-880, I-980.  FORMER: I-480, original I-880 in Sacramento.

17 currently signed, 1 unsigned, and one 3di and one potential 2di that could be signed in the future.  4 former designations (I-5W, I-15E, I-480, original I-880).

Love how you (intentionally?) left off everybody's favorite CA interstate

LOL, it was not intentional!  Not at all!  And I've been on 238 many many many times, I just forgot. LOL

Demonic Hellspawn Interstates don't count...

[Tom958]

Georgia: Fifteen.

16
20
24
59
75
85
95
185
285
475
516
520
575
675
985

[1995hoo]

The folks posting about Virginia came up short by omitting the most important one of all.

[ET21]

18 for Illinois if my count is correct. Soon to be 19 when I-490 is completed

[jp the roadgeek]

The folks posting about Virginia came up short by omitting the most important one of all.

I-366?

[thspfc]

7. Or 8. Or 9. Everybody's got their own opinion and they're all wrong.

Hmm? I-35, I-90, I-94, I-394, I-494, I-535, I-694. What are the others?

[hotdogPi]

7. Or 8. Or 9. Everybody's got their own opinion and they're all wrong.

Hmm? I-35, I-90, I-94, I-394, I-494, I-535, I-694. What are the others?

7: 35, 35W, and 35E are all the same
8: 35W and 35E count separately
9: 35, 35W, and 35E all count separately

[SkyPesos]

7. Or 8. Or 9. Everybody's got their own opinion and they're all wrong.

Hmm? I-35, I-90, I-94, I-394, I-494, I-535, I-694. What are the others?

7: 35, 35W, and 35E are all the same
8: 35W and 35E count separately
9: 35, 35W, and 35E all count separately

It's like this nerdy road question someone asked me once in a discord chat and there's multiple right answers depending how you take it

"How many 2di does I-2 intersect?"

[Henry]

WA has these:

5
82
90
182
205
405
705

So that's a total of 7.

[Scott5114]

Oklahoma is easy. 7, with one unsigned.

35 40 44
235
240
244 (444)

[davewiecking]

Counting the parent, MD has 12 in the "˜95 family: 95, 195, 295, 395, 495, 495X, 595, 695, 795, 895, 895A, 895B. Also 68, 70, 270, 270Y, 370, 81, 97 for another 7. 19 total.

[-- US 175 --]

TX:
2, 10, 14  , 20, 27, 30, 35/E/W, 37, 40, 44, 45, 69/E/C/W, 110, 169, 345, 369, 410, 610, 635, 820
= 20 (if branches are combined) or 25 (if branches are considered separate/individual)

[vdeane]

Since Virginia was already posted, here's the next closest - North Carolina.

This list includes current and future (not currently signed) routes. Combined, 9 mainline interstate highways, 14 auxiliary interstate highways, for a total of 23 interstate highways across the state.

I-26, I-40 (I-140, I-240, I-440, I-540, I-840), I-42, I-73, I-74 (I-274), I-77 (I-277), I-85 (I-285, I-485, I-785, I-885), I-87 (I-587), I-95 (I-295, I-795)

As the length of time since the interstate system was originally created gets arbitrarily large, the number of interstates in North Carolina approaches infinity.

[epzik8]

Counting the parent, MD has 12 in the "˜95 family: 95, 195, 295, 395, 495, 495X, 595, 695, 795, 895, 895A, 895B. Also 68, 70, 270, 270Y, 370, 81, 97 for another 7. 19 total.

Forgot 83, have never heard of 495X

[jmacswimmer]

Counting the parent, MD has 12 in the "˜95 family: 95, 195, 295, 395, 495, 495X, 595, 695, 795, 895, 895A, 895B. Also 68, 70, 270, 270Y, 370, 81, 97 for another 7. 19 total.

Forgot 83, have never heard of 495X

It's MDOT SHA's internal designation for the short Cabin John Parkway.

[cl94]

Since Virginia was already posted, here's the next closest - North Carolina.

This list includes current and future (not currently signed) routes. Combined, 9 mainline interstate highways, 14 auxiliary interstate highways, for a total of 23 interstate highways across the state.

I-26, I-40 (I-140, I-240, I-440, I-540, I-840), I-42, I-73, I-74 (I-274), I-77 (I-277), I-85 (I-285, I-485, I-785, I-885), I-87 (I-587), I-95 (I-295, I-795)

As the length of time since the interstate system was originally created gets arbitrarily large, the number of interstates in North Carolina approaches infinity.

[hotdogPi]

Since Virginia was already posted, here's the next closest - North Carolina.

This list includes current and future (not currently signed) routes. Combined, 9 mainline interstate highways, 14 auxiliary interstate highways, for a total of 23 interstate highways across the state.

I-26, I-40 (I-140, I-240, I-440, I-540, I-840), I-42, I-73, I-74 (I-274), I-77 (I-277), I-85 (I-285, I-485, I-785, I-885), I-87 (I-587), I-95 (I-295, I-795)

As the length of time since the interstate system was originally created gets arbitrarily large, the number of interstates in North Carolina approaches infinity.

We need to find the growth rate. It seems like O(t) (linear with time), but it could be O(√t) (slowing down gradually), O(log t) (slowing down a lot but eventually reaching ∞... eventually), or even O(t!) that will be like FritzOwl's plans within just five years and have every inch of land covered with Interstate in fifteen.

[I-55]

Since Indiana is already done, I'll crack at Mississippi:

10, *14*, 20, 22, 55, 59, 69

110, 220, 269 *310* *755*

That makes 8 signed routes, 1 longshot future interstate, and 2 route ideas that have never been formally proposed. Ideas for an I-61 or I-63 won't come around any time soon as Mississippi has enough to handle in I-69 and the rural 4 lane network is adequate.

[ilpt4u]

18 for Illinois if my count is correct. Soon to be 19 when I-490 is completed

Let us hash them out:

13 2DIs:
24
39
41 (maybe, barely)
55
57
64
70
72
74
80
88
90
94

11 3DIs:
155
172
180
190
255
270
280
290
294
355
474
490 Coming Soon

I believe 13 + 11 = 25, with the 26th coming soon

[US71]

4 "main" Interstates in Arkansas: 30, 40,49, 55

3d's : 540, 430, 630, 440, 530, 555

[ilpt4u]

4 "main" Interstates in Arkansas: 30, 40,49, 55

3d's : 540, 430, 630, 440, 530, 555

57 is on its way to make that a 5 for "main"  Interstates

[US71]

4 "main" Interstates in Arkansas: 30, 40,49, 55

3d's : 540, 430, 630, 440, 530, 555

57 is on its way to make that a 5 for "main"  Interstates

I keep trying to count it as a 30 extension, even though I know better