Really long interchanges

[empirestate]

What are some really long interchanges out there? By that I don't mean very large (area-wise) or complex ones; it could be something as simple as a diamond interchange, but for some reason the ramps are spread for some distance along the main freeway, such that it takes a while to drive through its full length.

A couple of sub-categories immediately occur to me:

-Single, one-piece interchanges (like the aforementioned diamond) that happen to be really stretched out for one reason or another.

-Split or multi-piece interchanges, where there's some intervening space between two half-interchanges that make up a logical whole. However, I would distinguish between split interchanges essentially at one location, and pairs of half-interchanges, say, at either end of a town, like at a business loop. Rule of thumb: if there are different exit numbers for each half, don't count it. (Though, I would give credit to something like I-80/215 in Utah, because its length really does stem from its unique layout rather than from being separate interchanges.)

-C/D systems. Obviously, some C/D roadway systems can stretch for many miles and encompass many interchanges along their length, so let's treat the C/D lanes equivalently to the main through roadway. In other words, count the length of the interchange only between where its ramps meet or diverge from the C/D roadway, without regard to where there is eventually access to the main freeway. (Likewise for service or frontage roads.)

One that always occurs to me is I-85/185 in Georgia, which stretches something like 2.3 miles from gore to gore.

[lordsutch]

A notably elaborate (and local) example: the ramp from I-75 south to Hartley Bridge Road in south Bibb County (exit 155), which is well over a mile long for a simple off-ramp.  Obviously this is to avoid a serious weaving motion with the I-475 merge.  The whole thing is also a little overbuilt since the ramps were obviously used as temporary roadways for I-475 traffic during the reconstruction (you can still see where they sanded off the pavement markings).

Another Georgia example: the direct ramp from GA 316 west to Pleasant Hill Road in Gwinnett County; it's gotta be 2+ miles from where you diverge from the mainline to finally arriving at Pleasant Hill Rd.  Again a weaving avoidance design.

[thenetwork]

The WB I-96 transition ramp from I-275 North to the official I-96 carriageways (at the I-96/I-275/I-696/M-5 interchange) checks in at about 2-1/2 miles.

[NE2]

I-70 at I-465 southwest of Indy. It's exit 69 eastbound and 73 westbound.

[empirestate]

I-70 at I-465 southwest of Indy. It's exit 69 eastbound and 73 westbound.

Hmm, that definitely gets into C/D territory, but I'll give it a good two miles or so from the easternmost slip ramps after the airport interchange (the last place the C/D returns traffic to the mainline).

Also everyone, don't forget to count the whole interchange's length, not just the one super-long ramp that contributes to it–which will undoubtedly be the case in many of these instances, but there may also be really long interchanges that consist only of short ramps. For example, I-70 at US 6 east of the Eisenhower Tunnels is pretty stretchy, although at only about a mile long there's probably a better example.

[JMoses24]

I-71 at Dana/Montgomery (exit 5) in Cincinnati. One ramp is .74 mile, plus two more of a third of a mile each, a third of .3 mile, and the last at .15 mile. If I've done my math right, it's 1.85 miles in length.

[jp the roadgeek]

Exit 7 off of CT 9 (CT 82) is a really long (about 2 mile) Super 2 that leads to CT 154.  The reason I put it up for qualification is that there is a little green entrance sign at the junction of CT 154 that one would find at a typical highway entrance in CT.

[vdeane]

I-81 exit 36 (Pulaski) currently counts, though the distance between the ends of the interchange is so large that when NYSDOT switches to mileage-based they'll likely have different numbers.  Exit 37 is less extreme.  Exit 51 is an elongated folded diamond.

There are a couple Thruway interchanges where the ramps themselves are really long.  Exits 33, 34A, and 58 come to mind.  Exit 24 also takes a while to traverse due to the I-90 flyovers.  And on the PA Turnpike, there's Breezewood, for once mentioned in a positive context!

[Grzrd]

Exit 86 on I-85 in Georgia connects I-85 with GA 13/Buford Highway and is approximately two miles long. Basically the "old I-85" section of GA 13 is used as a C/D system (Piedmont Road, Armour Drive and Monroe Drive traffic) for the "new" I-85, but GA 13 is an independent route that travels beyond the I-85 ramps in both directions.

Slightly OT: on SB I-85, the GA 13 Exit 86 ramp begins around Mile 88. Possibly by December 2013, that ramp will have a concurrent neighbor for a short stretch: the new ramp to NB GA 400.  Since the NB I-85 GA 400 exit is Exit 87, I assume the NB GA 400 ramp will also be Exit 87. (I have not checked the Plans to see how GDOT plans to implement the signage, "Exit Only" lanes, etc.)  Exits 86 and 87 at Mile 88, I think.

In the more distant future, US 19 has been approved to be relocated to the "old I-85" part of GA 13, but that apparently will not be done until if and when the Atlanta Street Car project is extended northward on Peachtree. If that happens, a US highway will partially serve as part of the C/D system for Exit 86.

[PHLBOS]

In Danvers, MA at the I-95/MA 114 interchange (Exits 47A-B); both the on-ramp from MA 114 to I-95 northbound and the Exit 47B ramp (from I-95 North to MA 114 West) are rather long and winding.

http://www.bing.com/maps/#JnE9LnBvcGVzJTJibGFuZSUyYmRhbnZlcnMlMjUyYyUyYm1hJTdlc3N0LjAlN2VwZy4xJmJiPTQyLjU2Nzc0NjEwNTQ5MjglN2UtNzAuOTYxMDcxNzI5NjYlN2U0Mi41NTc4OTk5OTQ5ODg1JTdlLTcwLjk3ODk4ODg4NTg3OTU=

[1995hoo]

I-95 near Potomac Mills Mall in Virginia. The C/D roads on either side of I-95 are quite lengthy. If you look at the Bing "Bird's Eye" view linked below, you'll see a cloverleaf (with one ramp relocated) at the bottom, a partial interchange above that, and then two flyover ramps serving the reversible center HOV carriageway just above that. All of those portions are served by the long C/D roads. (The other cloverleaf at the top of the image is a separate interchange.) From southernmost to northernmost ramp departures (per the OP's instructions) is 1.2 miles.

It bears noting that the "missing" ramp from the cloverleaf at the bottom of the image is in fact there, it just departs a lot earlier, closer to the partial interchange at the middle of the image (follow the ramp on the left side of I-95 there and you'll see how it splits).

The C/D road on the southbound side is longer than the northbound one because it also serves a rest area located south of the interchange (just out of view at the bottom of the image as I linked it).

http://binged.it/11eizDC

[InterstateNG]

The WB I-96 transition ramp from I-275 North to the official I-96 carriageways (at the I-96/I-275/I-696/M-5 interchange) checks in at about 2-1/2 miles.

I would consider those to be the official carriageways of 96 and the lanes from 696 to be the ramps.  They are pretty long in their own right.

[A.J. Bertin]

The main example that came to mind for me was the junction of I-96 and I-69 on the northwest side of the Lansing MI area. Going eastbound on I-96, it's Exit 89 for eastbound I-69. Going westbound on I-96 (concurrent with northbound I-69), the exit to head east on I-69 is Exit 91. There are several occasions throughout the year when I take the east-96-to-east-69 movement. That is quite a long ramp - as is the ramp from westbound I-69 to westbound I-96. Those ramps are probably at least two miles long.

[DTComposer]

In SoCal, the sequence of interchanges on I-405 from I-105 through La Cienega/Manchester features a number of long ramps, presumably to avoid weaving and merges between the interchanges. Although some are C/D roads, several are individual ramps, including I-405 NB to I-105 WB, I-405 NB to La Cienega, and I-105 EB to I-405 SB, each of which are at least 1 1/2 miles long.

[cpzilliacus]

In Anne Arundel County, Maryland, where the south end of I-97 ties in to U.S. 50/U.S. 301, along with the interchange at Md. 665, is pretty darned long (Google Maps here).

In Prince George's County, Maryland, the interchanges on the Capital Beltway (I-95/I-495) on the north (east) end of the Wilson Bridge are a long complex of interchanges with I-295 (Anacostia Freeway), the National Harbor access road, and Md. 210 (Indian Head Highway), also pretty long (Google Maps here).

On the other side of the Potomac River in the City of Alexandria and Fairfax County, Va., I think the interchanges at Va. 241 (Telegraph Road), U.S. 1 (Richmond Highway), and the partial interchange with Eisenhower Avenue also qualify as "long" (Google Maps here).

Back in Prince George's County, once the InterCounty Connector Contract D/E project is done, there will be a series of interchanges on I-95 from Md. 200 (ICC), Contee Road (to the new I-95 C-D lanes only) and Md. 198 (Sandy Spring Road), which will also be rather "long" (Google Maps here).

[agentsteel53]

in western New York, I-90 west (heading physically south) to US-219 south is not actually a long set of ramps, but I distinctly recall it being signed for "US-219 exit only" a good two miles back of the junction.

http://goo.gl/maps/8j31e

this quick Street View shows 219 in Clearview in a '61 spec shield, which is ... jarring.

[OCGuy81]

I'd nominate the US 60 Superstition Freeway and interchanges with Loop 101 and Loop 202 in Phoenix.  WB 60, for example, to 101 NB has a VERY long ramp before you end up on 101.

[cpzilliacus]

In SoCal, the sequence of interchanges on I-405 from I-105 through La Cienega/Manchester features a number of long ramps, presumably to avoid weaving and merges between the interchanges. Although some are C/D roads, several are individual ramps, including I-405 NB to I-105 WB, I-405 NB to La Cienega, and I-105 EB to I-405 SB, each of which are at least 1 1/2 miles long.

I agree with the above. Google maps does not really do it justice (here).

[Grzrd]

As an honorable mention, I'll include the ramp from Northcrest Road to SB I-85. Part C/D, its ramp component goes directly over I-285's Spaghetti Junction, achieving impressive height while doing so. It's not as long as the others already mentioned, but it provides a great vista at the top.

[empirestate]

I-71 at Dana/Montgomery (exit 5) in Cincinnati. One ramp is .74 mile, plus two more of a third of a mile each, a third of .3 mile, and the last at .15 mile. If I've done my math right, it's 1.85 miles in length.

No math needed; we want the distance traversed along the freeway rather than the sum of the ramp lengths. I get a rough measurement of 1.6 miles, along I-71 from the north end of the Dana Ave. ramps to the south end of the Montgomery on-ramp (being fairly conservative with how much of the ramp gore I include).

Exit 7 off of CT 9 (CT 82) is a really long (about 2 mile) Super 2 that leads to CT 154.  The reason I put it up for qualification is that there is a little green entrance sign at the junction of CT 154 that one would find at a typical highway entrance in CT.

It's definitely noteworthy as a hugely elongated trumpet, although its length passing through on CT 9 seems pretty typical.

There are a couple Thruway interchanges where the ramps themselves are really long.  Exits 33, 34A, and 58 come to mind.  Exit 24 also takes a while to traverse due to the I-90 flyovers.

Exit 24 is definitely protracted. As for the other three, those never struck me as being very long, but on the other hand Exit 25A is slightly stretched out along the Thruway to accommodate a railroad overpass, and Exit 39 similarly so.

Lots of good examples given of some highly braided urban interchanges...are there any more isolated rural ones, perhaps due to topography?

[Mr_Northside]

And on the PA Turnpike, there's Breezewood, for once mentioned in a positive context!

I guess Breezewood could be up to interpretation.  One might consider the original alignment between the mainline & US-30 as simply I-70 and not a ramp.

Though, thanks to a "fixed" interstate-to-PA-Turnpike direct connection that used to not exist, I'll put up the connection from I-176 to PA-10/23 - which used to be I-176, but now could be considered really long ramps.
http://goo.gl/maps/GJ0xG

[empirestate]

And on the PA Turnpike, there's Breezewood, for once mentioned in a positive context!

I guess Breezewood could be up to interpretation.  One might consider the original alignment between the mainline & US-30 as simply I-70 and not a ramp.

Hmm, Breezewood's definitely a special case. Certainly from the perspective of I-76, driving through the whole interchange doesn't take any abnormal amount of time, but if you consider I-70 as the through route it's quite an extended experience!

Though, thanks to a "fixed" interstate-to-PA-Turnpike direct connection that used to not exist, I'll put up the connection from I-176 to PA-10/23 - which used to be I-176, but now could be considered really long ramps.
http://goo.gl/maps/GJ0xG

Long ramps indeed, though in this case neither I-76 nor I-176 spends any conspicuous distance passing through the interchange. However, I-176 at interchange 1 is rather extruded due to the geometry of the SB off-ramp and the interpolation of a truck escape.

Casting about elsewhere in PA for an example, I find a very stretchy diamond interchange on PA 43 at Exit 44: http://goo.gl/maps/uebP7 - a scant mile long, but that's quite a bit for a simple diamond. The next interchange to the south is also like this, and if the interchange at the current north end of PA 43 were completed, it might be the longest of the bunch.

[1995hoo]

The ramps on the east side of the St. Lawrence connecting Autoroute 15 up onto the Pont Champlain are quite elongated–the loop ramp northbound traffic takes to access the bridge is about 1 km long:

http://binged.it/11bOQaJ

[Ian]

If you want to count it as one interchange, the I-84/I-291/I-384/US 6/US 44 interchange in Manchester, CT is rather long.

The ramps between I-95 and US 4/Spaulding Turnpike/NH 16 in Portsmouth, NH are fairly long.

[kphoger]

In the C/D category (subcategory quasi-C/D) is this one near Norman, OK, that always makes me wonder.  There is no physical barrier between lanes–just 0.4 miles of turn-only/exit-only lane bounded by a dotted line, followed by 0.6 miles of quasi-C/D lane bounded by a tiny flush median.  In an urban setting, this might not seem all that extraordinary, but this is on the edge of farmland.  Do we really need a full 0.6 miles of double solid white lines?