Highest Exit Sum in Your State...

[Roadsguy]

Pa's is at the Junction Of I-81 Exit 194 and I-476  Exit 131  near Scranton  for a total of 325. It could possibly !-76   and I-95 In Phila  but I dont think there is a direct connection between them

I guess my post wasn't there when you started writing this one.

Actually, like I said just earlier, I-76/276 at Valley Forge as well as I-80/81 both beat I-81/476. I-95/276 is surprisingly low, only 397 (~356 + ~41). I-295 won't factor in because of its bizarre east-west mileage starts at 0 there.

[sparker]

Within CA, the highest-numbered double-Interstate interchange would be I-5 (exit 522) with I-80 (exit 86), rendering a total of 608.  Of course, as has been previously stated, I-5 with CA 44 is somewhat higher (680); that's the farthest north freeway-to-freeway interchange in CA with exit numbers for both intersecting routes.  Of course, it would have been considerably higher prior to the rerouting of CA 299 in the Redding area several years back; if anyone has any pix of a EB CA 299 exit number at the I-5 interchange (if indeed exit numbering had been applied to 299 before the switch), please post if just for the purposes of edification!

[jp the roadgeek]

Connecticut: The interchange between I-91 and I-84 in Hartford. I-84's exit 51 + I-91's exit 32 equals 83.

Close, but a couple miles south you have I-91 North and CT 15 North.  I-91 to CT 15 North is Exit 29.  CT 15 North to I-91 North is Exit 89.  89+29= 118

[hotdogPi]

Within CA, the highest-numbered double-Interstate interchange would be I-5 (exit 522) with I-80 (exit 86), rendering a total of 608.  Of course, as has been previously stated, I-5 with CA 44 is somewhat higher (680); that's the farthest north freeway-to-freeway interchange in CA with exit numbers for both intersecting routes.  Of course, it would have been considerably higher prior to the rerouting of CA 299 in the Redding area several years back; if anyone has any pix of a EB CA 299 exit number at the I-5 interchange (if indeed exit numbering had been applied to 299 before the switch), please post if just for the purposes of edification!

(Data from OpenStreetMap)

I-5 and CA 99. 525+306=831.

[formulanone]

385 for Alabama, at I-65 and I-20/59 for exits 261 and 124, respectively.

[bzakharin]

Pennsylvania's largest sum is because of the way the Turnpike's and I-76's exit numbers are handled. The roads are one and the same for 326 miles until Valley Forge, after which both I-76 on the Schuylkill Expressway and I-276 on the Turnpike continue the exit numbers up to 351 and 358, respectively. Valley Forge is thus both Exit 326 of I-76 and Exit 326 of I-276, for a sum of 652. Quite a big number for state only about 300 miles across.

Correct me if I'm wrong, but there is no Exit 326 on the Schuylkill Expressway. The last exit is 327 and the Turnpike entrance is not marked as an exit.

New Jersey has Exit 354 on I-76 before NJ exit numbers kick in. Unfortunately it leads to Exit 1 of I-676 meaning the sum is only 355. Aside from that, the Garden State Parkway / I-80 interchange is 159+62 = 221 which is the maximum I believe.

[Henry]

WA: I-5 (182) and I-405 (31) north of Bothell, for a total of 213 (which is a technicality since I-405 does not have exit numbers on either end); if this were restricted to interchanges where both highways have exit numbers, it would be I-5 (164) and I-90 (2) in Seattle, for a total of 166. These junctions are a rarity in which it is not in an expected location.

[Roadsguy]

Pennsylvania's largest sum is because of the way the Turnpike's and I-76's exit numbers are handled. The roads are one and the same for 326 miles until Valley Forge, after which both I-76 on the Schuylkill Expressway and I-276 on the Turnpike continue the exit numbers up to 351 and 358, respectively. Valley Forge is thus both Exit 326 of I-76 and Exit 326 of I-276, for a sum of 652. Quite a big number for state only about 300 miles across.

Correct me if I'm wrong, but there is no Exit 326 on the Schuylkill Expressway. The last exit is 327 and the Turnpike entrance is not marked as an exit.

I'm going off the Turnpike's exit. The eastbound exit is Exit 326 for I-76, and the westbound exit is Exit 326 for I-276. It's really pushing it, but is indeed separate interstates. That's why I also included the I-80/81 sum.

New Jersey has Exit 354 on I-76 before NJ exit numbers kick in. Unfortunately it leads to Exit 1 of I-676 meaning the sum is only 355. Aside from that, the Garden State Parkway / I-80 interchange is 159+62 = 221 which is the maximum I believe.

Shows how small New Jersey is (or at least how few Interstates it has) that one road coming in from PA brings with it a single exit number bigger than the sum of any other two exit numbers in the state. :P

[bzakharin]

Shows how small New Jersey is (or at least how few Interstates it has) that one road coming in from PA brings with it a single exit number bigger than the sum of any other two exit numbers in the state.

It's definitely the former. Both these routes span the entire state, south to north and west to east respectively, and are the longest freeways in the state in their respective direction. The GSP's highest mile marker is 172.4. I-80's is 68.8 (though you can add 4 miles of I-95 to get to the NY state line from 80's eastern terminus).

NJ has a pretty adequate freeway (if not all Interstate) system. The only important missing link is between Trenton and I-287, the cancelled Somerset Freeway. Some nice to haves would be the completion of NJ 55, something along the western state line north of Trenton, and something along the US 40 corridor. None of these would increase the maximum mileage.

[spooky]

Little Rhody's is 19. I-195 splits at I-95 and there is no exit number. The exit number for I-195 off on I-95 is 19.

Actually it is 20 because I-195 has a different exit number on I-95 SB.

[vdeane]

I think in New York, if you allow that the Thruway interchange is part of the Exit 131 complex from NY 17, then that would be the winner. Adding the Thruway's exit number for NY 17, which is Exit 16, you get 147.

(And if you also add in the Woodbury toll barrier, which is located within the interchange, and for toll collection purposes is designated Exit 15, then you get 162.)

Because of how the Thruway interrupts the exit sequences of both I-87 and I-90, there's really no other competitive option in the state. I-495 gets up to Exit 71, but nothing intersects it that far east (and even if it did, it would only be able to add a handful of exits to the sum total).

I personally wouldn't, since I consider exit 131 to be specifically for NY 17/NY 32, with the ramps to the Thruway unnumbered, and since I wouldn't include the barrier.  The only other one that would compare, though, would be I-84/NY 17 at 125 (4 and 121).  The next one down is probably the Bruckner at 91 (54/6/19/12).

Florida's is I-75/I-10 (435/296): 731

Pa's is at the Junction Of I-81 Exit 194 and I-476  Exit 131  near Scranton  for a total of 325. It could possibly !-76   and I-95 In Phila  but I dont think there is a direct connection between them

I guess my post wasn't there when you started writing this one.

Actually, like I said just earlier, I-76/276 at Valley Forge as well as I-80/81 both beat I-81/476. I-95/276 is surprisingly low, only 397 (~356 + ~41). I-295 won't factor in because of its bizarre east-west mileage starts at 0 there.

PA doesn't use exit 0.  Most freeways begin at exit 1 (though some do have unnumbered termini) and I can't imagine why they wouldn't here.

[bzakharin]

According to the visualizations here (https://www.patpconstruction.com/paturnpikei95/drive-thru-south-to-north.aspx) none of the routes involved in the interchange (95/295/276) have exit numbers at the interchange.

[hbelkins]

Kentucky's entrants in this game are the Western Kentucky Parkway (137) at I-65 (91) for a sum of 228, and I-71 (77) at I-75 (173) for a total of 250.

[dfilpus]

North Carolina -
Western US 70/US 17 - 410 + 147 = 557
Eastern US 70/US 17 would be larger, but US 17 uses the US 70 exit number.

[PurdueBill]

Some low ones:

Massachusetts: 84. Exit 44 on I-93 and Exit 40 on I-495. (I-495 doesn't have a numbered exit when it merges with I-95 in Salisbury.)

New Hampshire: Absolutely nothing qualifies. Interstate junctions are unnumbered in New Hampshire.

Vermont: Again, nothing qualifies. I-89 and I-93 are both unnumbered at I-91, I-189 doesn't have exit numbers, and the US route and state route freeways don't connect to the Interstates or to each other.

I'm pretty sure that I-93 is Exit 19 on I-91.  For NH, I-393 is signed as Exit 15E on I-93 along with the US routes.  Would that qualify?  (Not that 19 and 15 are impressive, but they are something at least)

[hotdogPi]

Some low ones:

Massachusetts: 84. Exit 44 on I-93 and Exit 40 on I-495. (I-495 doesn't have a numbered exit when it merges with I-95 in Salisbury.)

New Hampshire: Absolutely nothing qualifies. Interstate junctions are unnumbered in New Hampshire.

Vermont: Again, nothing qualifies. I-89 and I-93 are both unnumbered at I-91, I-189 doesn't have exit numbers, and the US route and state route freeways don't connect to the Interstates or to each other.

I'm pretty sure that I-93 is Exit 19 on I-91.  For NH, I-393 is signed as Exit 15E on I-93 along with the US routes.  Would that qualify?  (Not that 19 and 15 are impressive, but they are something at least)

Even if I-93 is Exit 19 on I-91, I-93 is unnumbered at its terminus. Similarly, I-393 is unnumbered where it meets I-93, despite it being Exit 15E on I-93.

[rlb2024]

Louisiana: I-10 (exit 267) + I-12 (exit 85) + I-59 (exit 1) = 353

[sparker]

Within CA, the highest-numbered double-Interstate interchange would be I-5 (exit 522) with I-80 (exit 86), rendering a total of 608.  Of course, as has been previously stated, I-5 with CA 44 is somewhat higher (680); that's the farthest north freeway-to-freeway interchange in CA with exit numbers for both intersecting routes.  Of course, it would have been considerably higher prior to the rerouting of CA 299 in the Redding area several years back; if anyone has any pix of a EB CA 299 exit number at the I-5 interchange (if indeed exit numbering had been applied to 299 before the switch), please post if just for the purposes of edification!

(Data from OpenStreetMap)

I-5 and CA 99. 525+306=831.

Overlooked that one; when I was living up in that area, the 5/99 interchange utilized 5's numbers for the whole shooting match; apparently that's changed with the extension of the CA 99 freeway.  Thanks to 1 for unearthing that piece of info -- that indeed would be the highest aggregate exit # within the state!

[US 89]

At the interchange between I-15 and US 89 in Farmington UT, the I-15 numbers are 324-325 and the US-89 numbers are 394-395. However, the ramp from 89 to 15 south is unnumbered, and there isn't a direct ramp from 89 south to 15 north. That movement requires using Park Lane, which is exit 395 on 89 and 325 on 15. So you could make a case that Utah gets up to 720.

Also, are we including single interchanges where three routes intersect? If we're allowing three routes, then you can add the Legacy Parkway to that Farmington interchange, which would get it up to 733.

[empirestate]

I think in New York, if you allow that the Thruway interchange is part of the Exit 131 complex from NY 17, then that would be the winner. Adding the Thruway's exit number for NY 17, which is Exit 16, you get 147.

(And if you also add in the Woodbury toll barrier, which is located within the interchange, and for toll collection purposes is designated Exit 15, then you get 162.)

Because of how the Thruway interrupts the exit sequences of both I-87 and I-90, there's really no other competitive option in the state. I-495 gets up to Exit 71, but nothing intersects it that far east (and even if it did, it would only be able to add a handful of exits to the sum total).

I personally wouldn't, since I consider exit 131 to be specifically for NY 17/NY 32, with the ramps to the Thruway unnumbered, and since I wouldn't include the barrier.

The only consideration I'd add is that, since NY 17 exits off of itself here, the "mainline" continuing toward the Thruway ramps is itself, in a sense, an "exit". But that's a stretch.

[thenetwork]

I think in New York, if you allow that the Thruway interchange is part of the Exit 131 complex from NY 17, then that would be the winner. Adding the Thruway's exit number for NY 17, which is Exit 16, you get 147.

(And if you also add in the Woodbury toll barrier, which is located within the interchange, and for toll collection purposes is designated Exit 15, then you get 162.)

Because of how the Thruway interrupts the exit sequences of both I-87 and I-90, there's really no other competitive option in the state. I-495 gets up to Exit 71, but nothing intersects it that far east (and even if it did, it would only be able to add a handful of exits to the sum total).

If they ever convert the Thruway to mileage-based exits and keep the current mile-markers intact, then somewhere around Buffalo would likely be home to the highest number, no?

[Flint1979]

For Michigan it has to be 469 (I-94 and I-69 in Port Huron).

[PurdueBill]

Some low ones:

Massachusetts: 84. Exit 44 on I-93 and Exit 40 on I-495. (I-495 doesn't have a numbered exit when it merges with I-95 in Salisbury.)

New Hampshire: Absolutely nothing qualifies. Interstate junctions are unnumbered in New Hampshire.

Vermont: Again, nothing qualifies. I-89 and I-93 are both unnumbered at I-91, I-189 doesn't have exit numbers, and the US route and state route freeways don't connect to the Interstates or to each other.

I'm pretty sure that I-93 is Exit 19 on I-91.  For NH, I-393 is signed as Exit 15E on I-93 along with the US routes.  Would that qualify?  (Not that 19 and 15 are impressive, but they are something at least)

Even if I-93 is Exit 19 on I-91, I-93 is unnumbered at its terminus. Similarly, I-393 is unnumbered where it meets I-93, despite it being Exit 15E on I-93.

But at least it would give something for Vermont and New Hampshire to have totals of 19 and 15 (19+nothing and 15+nothing). 
New Hampshire really makes it hard.  NH 101 at I-95 even skips having an exit number at all, even though I-95 has an exit number for 101.  Can't they make it consistent somehow?

[OracleUsr]

North Carolina -
Western US 70/US 17 - 410 + 147 = 557
Eastern US 70/US 17 would be larger, but US 17 uses the US 70 exit number.

I imagine the next-highest would be I-40 at I-85 at the east end of the duplex:  163 + 259 = 422

[HazMatt]

North Carolina -
Western US 70/US 17 - 410 + 147 = 557
Eastern US 70/US 17 would be larger, but US 17 uses the US 70 exit number.

US 64/I-95 - 464 + 138 = 602.  Both our answers will change once I-87 and I-42 get going.