Interstates which exit off of themselves

[1995hoo]

In Springfield, VA, you get the situation where 95 comes up from southern Fairfax County and then co-routes with the outer loop of the Beltway (495) heading through southern Alexandria. As a result, one who wishes to stay on 95 proper must exit to continue on 95. If you don't exit, it becomes 395 heading towards DC.

However (95 hoo maybe you can confirm my facts), interestingly, they don't call the ramp which lets you continue on 95 north an exit. Rather, if you stay in the middle of the carriageway and head in the same cardinal direction (with the road becoming 395), they consider it an "exit". https://www.google.com/maps/@38.7720371,-77.1820766,3a,75y,24.6h,78.76t/data=!3m6!1e1!3m4!1svdUPA1TYyqF06VwsUtzc2g!2e0!7i13312!8i6656

The same goes for southbound traffic. When you're on 395 coming southbound, if you stay on the carriageway and let it become 95 southbound, you've "exited". (https://www.google.com/maps/@38.79797,-77.1686638,3a,75y,233.61h,85.5t/data=!3m6!1e1!3m4!1seHiQv7rTZGaun1Am6n3wig!2e0!7i13312!8i6656)

Yes, I-95 through Springfield does not exit off of itself.  When the interchange was reconstructed, there was a deliberate effort to make I-95 the through movement via those big and soaring ramps.

One could probably debate how the average motorist views it. That is, the I-95 thru movements are not signed as "exits." But the two flyovers carrying I-95 are two lanes each, while other movements at that interchange have as many as four lanes. If you're on the Inner Loop (I-95 South/I-495 West), four lanes continue straight on the Beltway and two other lanes bear left onto the I-95 flyover. The four lanes are signed on some (but not all!) signs as "Exit 170A" on the theory you're "exiting" I-95 onto I-495. I'm 100% certain most motorists don't view it that way, regardless of whether I-95 "should" carry a higher status than I-495.

I believe Maryland's companion interchange near College Park doesn't sign the Beltway thru movements as an "exit."

[roadman65]

Should not the road with the most lanes be the through route, and not the straight road?  If both have the same lanes each way then neither exits sort of like SB I-295 at I-76 before the direct connection project took place where 3 lane I-295 split into the two lane left exit that continued straight and the two right lanes (where the center lane split into two) veered to the right. The two through lanes veered to the right to make it look like an exit of itself, but considering its equal to the other road going straight in lanes, I would say that is an equal split and not one road exiting the other, although technically I-76 is really an exit from I-295 though.

[mwb1848]

One of the absolute worst:

I-10 WB in San Antonio:
https://goo.gl/maps/NkGXE

At least in the EB configuration, I-35 SB continues in the mainlanes:
https://goo.gl/maps/L3yF3

[roadman65]

Then there is I-410 at the NE interchange of I-35.  The main beltway not only does a meaningless dogleg, but narrows to one lane to go SB from EB and from NB to WB at the North end of the two interstate concurrency there.

[bzakharin]

Should not the road with the most lanes be the through route, and not the straight road?  If both have the same lanes each way then neither exits sort of like SB I-295 at I-76 before the direct connection project took place where 3 lane I-295 split into the two lane left exit that continued straight and the two right lanes (where the center lane split into two) veered to the right. The two through lanes veered to the right to make it look like an exit of itself, but considering its equal to the other road going straight in lanes, I would say that is an equal split and not one road exiting the other, although technically I-76 is really an exit from I-295 though.

When the number of lanes is equal, it's down to other criteria, such as whether it's a center lane split or an extra lane being added on the right/left. For example, where the Atlantic City Expressway begins at NJ 42, NJ 42 feels like the through route because there is an extra lane added on the left for the AC Expressway exiting. If one of the roads leaves at a substantial curve, while the other is relatively straight, the former feels like an exit. This is the case with I-55 as mentioned by the OP. I'd argue that that was also the case for the 295/76/42 situation until they were split up. In fact, I-295 still feels like a ramp through that area.

[roadman65]

Then you might as well consider I-280 in Newark, NJ as one as you have to not only take a two lane mainline bearing off to the right of a three lane exit ramp for First Street, but the two through lanes continuing for I-280 are lanes added from the Garden State Parkway/Clinton Street merge.  In reality you must shift over to all new travel lanes going EB or else if you remain in any of the three lanes of I-280 from its conception, you will find yourself exiting onto First Street and off the interstate.

[ekt8750]

I-676 in Camden right off the foot of the Ben Franklin Bridge exits off the mainline (US 30) to get to the North-South Freeway.

[vdeane]

I-87, both directions, on either side of the I-90 overlap
I-90 when leaving the Thruway (EB at exit 24 and WB at exit B1)
I-390 SB at I-590

[roadman65]

Oh yes, how could I forget I-83 S Bound at PA 581 as well.   Also its northbound counterpart exits itself and even with the new N Bound upgrade, still it will go from the Harrisburg-Baltimore Expressway to the Harrisburg Expressway (Capitol Beltway) as a glorified ramp when completed.

[bzakharin]

Then you might as well consider I-280 in Newark, NJ as one as you have to not only take a two lane mainline bearing off to the right of a three lane exit ramp for First Street, but the two through lanes continuing for I-280 are lanes added from the Garden State Parkway/Clinton Street merge.  In reality you must shift over to all new travel lanes going EB or else if you remain in any of the three lanes of I-280 from its conception, you will find yourself exiting onto First Street and off the interstate.

Well, yes, I would consider that. I forgot about that one since it's been a while since I've been there.
As you yourself said:

Should not the road with the most lanes be the through route, and not the straight road? 

So this qualifies by any criteria

[roadman65]

Bottom line is that if non freeway number routes can turn at intersections where the main road goes straight with more lanes, then so can interstates exit themselves with less lanes than the through road numbered as an exit.

Also I-295 N Bound entering New Jersey from Delaware exits US 40, however NJDOT did not assign exit numbers for US 40 E Bound, but only for NJ 49 and US 130.  I-295 is two lanes and last time I was there it was two for US 40.  Being US 40 is the main freeway here with I-295 curving out of the way with US 40 W Bound long side of the US 40 E Bound lanes we can simply say that.

I guess bz I do really agree with you there as far as being an even split.  Its iffy at best.

[Pete from Boston]

I-95 South exits itself if you are on the lower level of the George Washington Bridge / Express lanes. I-80 (which begins here) is the through route. From the upper level / local lanes, it's more of a 50/50 split, but I-95 is on the left, so it can be considered the through route. Then, the currently unsigned I-95 exits itself from the NJ Turnpike onto the PA Extension (Exit 6). Presumably once the PA Turnpike Interchange is completed, it will exit itself again at that interchange and onto the existing I-95.

I-87 exits itself Southbound where I-287 East is the through route. I-676 arguably exits itself just east of the Ben Franklin Bridge where US 30 is the through route.

I'd say 95 South also exits itself where the New England Thruway meets 695.

And of course, the BQE going north (nominal west) infamously exits itself via a little ramp where through traffic continues to the Battery Tunnel, backing ramp traffic way up the right lanes of the BQE.

[1995hoo]

Honorable mention for a route that no longer qualifies: I-95 used to exit from itself three times in Maine. Once onto what is now I-495, a few seconds later onto what is now I-295, then a third time up at where what is now I-295 rejoins the Maine Turnpike.

Regarding I-278, it also has those little single-lane ramps southeast of the Triboro Bridge where it briefly connects to Grand Central Parkway.

Thinking of I-278 reminds me of how I-395 in DC exits off itself, practically speaking, to connect between the Southwest—Southeast Freeway and the Third Street Tunnel. As with the Springfield Interchange mentioned earlier in the thread, it's not signed as an exit; eastbound, there's a new exit number to continue on the Freeway onto I-695, though nobody thinks of it as an "exit." The northbound I-395 mainline has a very brief single-lane spot as you curve down towards the tunnel and the left lane exits to D Street SW.

[doorknob60]

I-84 at Jct. I-86: https://www.google.com/maps/@42.5696784,-113.5237246,3a,75y,82.43h,86.32t/data=!3m6!1e1!3m4!1sPDPAhrGILpG9deL8FAt9bw!2e0!7i13312!8i6656

It's very rural so it doesn't cause much of a problem.

[noelbotevera]

I-84 at Jct. I-86: https://www.google.com/maps/@42.5696784,-113.5237246,3a,75y,82.43h,86.32t/data=!3m6!1e1!3m4!1sPDPAhrGILpG9deL8FAt9bw!2e0!7i13312!8i6656

It's very rural so it doesn't cause much of a problem.

It's on 30.

[doorknob60]

I-84 at Jct. I-86: https://www.google.com/maps/@42.5696784,-113.5237246,3a,75y,82.43h,86.32t/data=!3m6!1e1!3m4!1sPDPAhrGILpG9deL8FAt9bw!2e0!7i13312!8i6656

It's very rural so it doesn't cause much of a problem.

It's on 30.

Yes it is US-30, and Google for some reason puts that as the primary route, but it's also still I-84 coming into that interchange, I-86 if you continue straight, and I-84 if you exit.

And at the other end, I-15 exits off itself, though this one is a multiplex between I-84 and I-15 so it's not as much of an example (plus the exit is 2 lanes, not 1): https://www.google.com/maps/@41.7007175,-112.1842679,3a,75y,301.29h,84.96t/data=!3m7!1e1!3m5!1sQd57QicLcDy-iG7tw_TEBg!2e0!5s20130801T000000!7i13312!8i6656

[Bruce]

I-84 at Jct. I-86: https://www.google.com/maps/@42.5696784,-113.5237246,3a,75y,82.43h,86.32t/data=!3m6!1e1!3m4!1sPDPAhrGILpG9deL8FAt9bw!2e0!7i13312!8i6656

It's very rural so it doesn't cause much of a problem.

It's on 30.

Yes it is US-30, and Google for some reason puts that as the primary route, but it's also still I-84 coming into that interchange, I-86 if you continue straight, and I-84 if you exit.

And at the other end, I-15 exits off itself, though this one is a multiplex between I-84 and I-15 so it's not as much of an example (plus the exit is 2 lanes, not 1): https://www.google.com/maps/@41.7007175,-112.1842679,3a,75y,301.29h,84.96t/data=!3m7!1e1!3m5!1sQd57QicLcDy-iG7tw_TEBg!2e0!5s20130801T000000!7i13312!8i6656

US 30 might be listed there because it continues onto I-86, thus both sections are US 30.

[GaryV]

In addition to those mentioned by the OP, I-69 must exit onto / from I-465 at both intersections at Indianapolis.

[iBallasticwolf2]

I-75 and I-71 in OH.
I-71 at I-75 in KY.
I-74 at I-275 east of Miamitown.
I-275 at I-74 west of Miamitown.
Each end of the I-70/I-71 concurrency in Columbus.
Each end of the I-85/I-75 concurrency in Atlanta.
Each end of the I-75/I-64 concurrency in Lexington.

[lepidopteran]

I-75 SB in Knoxville, TN, where it joins I-640.
Before this was built, I-75 NB left the I-40 concurrency via a rather tight (and easy-to-miss) loop ramp.

[GaryV]

I thought of more instances on I-69.  Coming out of Port Huron, you have to exit the 69/94 concurrency to continue on I-69 west.  And on the west side of Lansing, I-69 exits from I-96 in either direction.

[hbelkins]

I-75 and I-71 in OH.
I-71 at I-75 in KY.
I-74 at I-275 east of Miamitown.
I-275 at I-74 west of Miamitown.
Each end of the I-70/I-71 concurrency in Columbus.
Each end of the I-85/I-75 concurrency in Atlanta.
Each end of the I-75/I-64 concurrency in Lexington.

That's not how it works. That's now how any of this works.

"Exit from self" means that the interstate leaves the mainline via a ramp, while the through route continues under another designation. A split between two signed interstates wouldn't count. However, a situation like I-76 eastbound at I-277 would. The through route continues as I-277 (semicolon) to stay on I-76 you have to take a ramp.

[cl94]

I-75 and I-71 in OH.
I-71 at I-75 in KY.
I-74 at I-275 east of Miamitown.
I-275 at I-74 west of Miamitown.
Each end of the I-70/I-71 concurrency in Columbus.
Each end of the I-85/I-75 concurrency in Atlanta.
Each end of the I-75/I-64 concurrency in Lexington.

That's not how it works. That's now how any of this works.

"Exit from self" means that the interstate leaves the mainline via a ramp, while the through route continues under another designation. A split between two signed interstates wouldn't count. However, a situation like I-76 eastbound at I-277 would. The through route continues as I-277 (semicolon) to stay on I-76 you have to take a ramp.

I-71 at SR 315 counts. Freeway continues as SR 315 while NB I-71 traffic has 1/4 mile to merge into an auxiliary lane added at Exit 105.

I'll add:
-I-90 WB at I-271
-I-90 (both directions) at I-71
-I-70 at I-670
-I-76 and I-80 where they intersect
-I-86 WB at I-390
-I-95 at I-278/I-295
-I-95 at I-695
-I-278 WB at Grand Central Parkway (don't think this was mentioned)

[tmthyvs]

• I-90 just east of Billings (through movement is to I-94)
• I-80 west of Des Moines and I-35 north of Des Moines (through movements go to either end of I-235)

[national highway 1]

I-5 northbound has to exit itself at the split with CA 99 at Wheeler Ridge (Exit 221). Also I-5 northbound has to exit itself at the I-580 junction near Vernalis (Exit 446).