Longest interstate concurrences

[The High Plains Traveler]

What about three digit numbers overlapped with two digits?  I have seen plenty that use the three digit route number exits such as around Knoxville, TN.  I-75 uses I-640's exit numbering.

Then, as mentioned before, I-83 uses I-695's numbers even though no exits during the overlap, it is at the split that I-83 leaves I-695 with an exit number and not I-695 leaving I-83.

I-94/694 in the NW Twin Cities uses the 494/694 exit numbers. Theoretically there could be an exit number duplication along I-94 in Minnesota (30-34 range), but none of the exits in this short stretch duplicate any along  I-94.

[roadman65]

I-64 in Virginia gives up its own exit numbering where duplexed with both I-81 and I-95. 

In both cases the other interstate with the higher number are the straight through routes, and in Richmond it was part of the tolled Richmond- Petersburg Turnpike where it always had its own sequential numbering from 1 to 17.  Even in the past I-95 had to give up its own numbering until the toll road was allowed to use I-95's sequential system.

[Strider]

The 40/85 concurrency in NC is not the longest, but it is a blast to drive. Not much in the way of speed traps and traffic tends to flow very fast there. Very well designed, IMO. 

I agreed completely. I drove on that stretch a lot and LOVED every minute of it. Everybody goes fast on that stretch. It sure feels like the stretch of I-95 between Richmond and Washington, D.C.

[Zzonkmiles]

The 40/85 concurrency in NC is not the longest, but it is a blast to drive. Not much in the way of speed traps and traffic tends to flow very fast there. Very well designed, IMO. 

I agreed completely. I drove on that stretch a lot and LOVED every minute of it. Everybody goes fast on that stretch. It sure feels like the stretch of I-95 between Richmond and Washington, D.C.

The 40/85 concurrency in NC is not the longest, but it is a blast to drive. Not much in the way of speed traps and traffic tends to flow very fast there. Very well designed, IMO. 

I agreed completely. I drove on that stretch a lot and LOVED every minute of it. Everybody goes fast on that stretch. It sure feels like the stretch of I-95 between Richmond and Washington, D.C.

We must be long-lost twins. I LOVE the stretch of I-95 between Richmond and DC. I especially like how so much of the interstate there has the northbound and southbound lanes separated by the trees, so you are basically racing through the pines without the distraction of the oncoming traffic. Another fun section was I-85 in Virginia from Petersburg to the NC state line. It's not a concurrency, but it is still a fun and easy drive through the middle of nowhere.

I'll tell you which concurrency I DON'T like. It's that miserable I-75/85 garbage in Atlanta. Hell no!!!

[signalman]

I'll tell you which concurrency I DON'T like. It's that miserable I-75/85 garbage in Atlanta. Hell no!!!

I've always wanted to drive the Downtown Connector.  I am sure traffic is a bitch through there, but if it's free flowing, it looks fun.  I'd definitely drive it at an off peak time; either late at night or an early Sunday morning.

[MrDisco99]

I love driving on the Atlanta connector when traffic is flowing... REALLY wide with lots of fun curves and underpasses go great with some loud fast music playing in the car.

During the weekday when traffic is a crawl, though, it's the worst drive ever.

BTW exit numbers follow I-75, I've always assumed because the I-75 mileage by that point is way higher than I-85 ever reaches in GA.

[Strider]

Thread resurrection!

I-73/I-74 in NC is multiplexing for 68 miles. (construction unfinished in some areas)

I-40/I-85 for 31 miles in NC

I-90/I-94 in IL and WI (they are the only interstates that met and concurrency twice)

I-20/I-59 in AL and MS

I-40/I-55; I-40/I-65, I-40/I-24, I-40/I-75 in TN

There are more out there.

As far as I know, I-80 and I-90 is the longest concurrence of all.

[Great Lakes Roads]

When I-69 gets done with construction between Martinsville and Indianapolis, I-69 will use I-465's exit numbers on the east side of Indy.
I-70 uses I-65's exit numbers from the South Split to the North Split in downtown Indianapolis.
I-74 uses I-465's mileage from the west side of Indy to the east side.
I-80 uses I-94's exit numbers until the Toll Road, then uses I-90's mileage from Lake Station to the Ohio state line.

[sprjus4]

The small overlap with I-87 and I-440 in Raleigh on its southern end to connect with I-40 utilizes I-440 exit numbers and mileage.