Most intersections between the same two routes?

[hbelkins]

Which two routes intersect the most number of times? In total, and within each state/province/equivalent?

For purposes of this discussion, a state route only applies in its individual state. For instance, MSR 16 (NC/VA/WV) intersects US 19 in both Tazewell, Va., and multiple times in West Virginia, but the Virginia intersection does not count in the total.

Discontinuous routes are separate routes. I-76 CO/NE is not the same as I-76 OH/PA/NJ.

The routes must intersect directly. For instance, Exit 28 on I-64 in West Virginia is signed for US 60, but the route actually intersected is not US 60, but a county route. It does not count in the total.

The beginning and end of a concurrency only counts for one intersection, not two. For instance, Exits 97 and 99 on I-75 in Kentucky only count as one intersection of I-75 and US 25, not two, since the routes are concurrent between the two exits.

I-64 and US 60 intersect in Kentucky seven times. That's more than US 25 and I-75, or US 31W and I-65.

If I had to guess the national winner, it would be I-95/US 1.

[TheOneKEA]

In Maryland:

I-70 and US 40 intersect four times.
MD 7 and US 40 intersect eight times, but it might not count because MD 7 is discontinuous.

[mrcmc888]

In Virginia, US 11 crosses I-81 sixteen times and forms a concurrency with it once.

[Bitmapped]

By the listed rules, I-70 and US 40 have nine intersections in Ohio. Ten if you include the interchange on the Indiana border where some ramps enter Ohio.

[bassoon1986]

Louisiana has 5 interchanges between US 80 and I-20. Twice more where 80 crosses with no interchange.

There are 4 between US 90 and I-10.

Nationally there are:
11 Between 80/20
24 Between 90/10


iPhone

[Max Rockatansky]

I'm sure on the exact amount of times but CA 1 intersecting US 101 in California is the most common instance here. 

[CtrlAltDel]

I didn't check to see if all of the criteria were met, but a preliminary count indicates that I-75 meets US-41 14 times. Once in Florida, twice in Tennessee, and eleven times in Georgia.

[sparker]

I'm sure on the exact amount of times but CA 1 intersecting US 101 in California is the most common instance here. 

If you count a (consistently) signed concurrency as a single intersecting point, the US 101/CA 1 combination has 7 intersections.  Within CA, the only other combination that comes remotely close is I-5 and CA 33 with 4 intersecting points. 

[TheHighwayMan3561]

One factor not addressed in the OP: do the routes have to exchange directly or do grade-separated crossings with no access count?

[Eth]

I didn't check to see if all of the criteria were met, but a preliminary count indicates that I-75 meets US-41 14 times. Once in Florida, twice in Tennessee, and eleven times in Georgia.

My own count gives 12 times in Georgia, and that's not counting Exit 255 (where the northbound ramps go directly to US 41 but the southbound ramps don't, and the routes don't actually cross) or one other crossing without an interchange (and counting the overlap from Exit 22 to Exit 29 only once).

At any rate, surely nothing else in Georgia comes close to that.

[Rothman]

I-91 and US 5 usually is brought up in this discussion.

[wanderer2575]

I-96 (Michigan) has eight interchanges with former US-16 (Cascade Road and Grand River Avenue).

[jeffandnicole]

If I had to guess the national winner, it would be I-95/US 1.

In regards to I-95, I wouldn't be surprised it intersected with US 301 more than US 1.

[roadman65]

US 9W and NY 32 meet i think 4 times.

[roadman65]

If I had to guess the national winner, it would be I-95/US 1.

In regards to I-95, I wouldn't be surprised it intersected with US 301 more than US 1.

11 times including the southbound 301 crossing over and back over I-95 at Richmond.

23 i counted for US 1 not including its southern terminus in Miami and including 15E on the NJ Turnpike.

[Bickendan]

I-5 and OR 99 have 12, 14 if counting the old Wolf Creek turn off.

I-84 and US 30 have 20.

[sprjus4]

If I had to guess the national winner, it would be I-95/US 1.

From Florida to Maine, 37 total times where the routes intersect with at least one connection, an additional 3 times where they intersect with a grade-separation and no connection.

In regards to I-95, I wouldn't be surprised it intersected with US 301 more than US 1.

Only 19 total times where the routes intersect with at least one connection, all in South Carolina, North Carolina, and Virginia.

[froggie]

I-91 and US 5 usually is brought up in this discussion.

8 direct interchanges in Vermont alone.  Regarding HighwayMan394's question, there are 11 additional grade separations between 91 and 5 in Vermont.  And 2 additional "possibles" where the routes don't cross but there are direct ramps between the two.

[michravera]

I'm sure on the exact amount of times but CA 1 intersecting US 101 in California is the most common instance here.

.... including several times each in several counties!

[pianocello]

One of the Midwest's leaders is likely I-74 and US 150. They cross each other 10 times, 7 of which are interchanges. That doesn't count the double-trumpet interchange in Peoria between the two where they don't cross.

I-80 and US 6 have 12 crossings/overlaps, 8 of which are interchanges.

[hbelkins]

One factor not addressed in the OP: do the routes have to exchange directly or do grade-separated crossings with no access count?

There must be an intersection, where you can move from one road to the other. Grade-separated crossings with no access do not count.

[thspfc]

On a national scale, I-80/US-6 has to be up there.

In WI, I-94 and US-12 cross seven times, though one of those crossings does not have an interchange.

[TheHighwayMan3561]

MN doesn't have anything thrilling for this. Thinking it's I-35/MN 23 with a measly 3:
duplex from Exits 180-191
Exit 195
Exit 251B

[US 89]

First one I thought of was the aforementioned I-75/US 41 combination.

Utah doesn't have anything too exciting in this department. The best I can come up with is I-15 and US 89: coming from the south, US 89 crosses I-15 without an interchange just north of exit 279, then concurs with I-15 from exit 282 to 291. There's a weird bump at exit 312 that I'd say counts as an intersection, and then there's another concurrency from exit 317 to 324, which adds to a total of 6.

[NWI_Irish96]

The best Indiana can do is I-65 and US 31, which have 6 interchanges.
I-65 has 4 interchanges with US 231.