3di/3dus

[Duke87]

US202/I-395 in Bangor, ME

There are none in Connecticut.

[TheStranger]

Once I-285 is signed through Winston-Salem, it will run concurrent with a segment of US 311.

[TheStranger]

Someone beat me to I-581 and US 220.

How about former I-181 and US 19W in Tennessee? No one said one of the digits in the 3dus couldn't be a letter.

In THAT case, that makes US 287 and US 377 with I-35W in Fort Worth count, right?   Also included in that distinction: US 25W and I-640 in Knoxville...

[dfilpus]

The entirety of North Carolina's new I-795 is corouted with 3dus routes!  (US 117 for a majority of it, US 264 at the north end)

EDIT: As noted by deathtopumpkins' post above, 117 is now on old US 117A, but that leaves US 264 with I-795 at the north terminus!  Not sure if 117 runs with the 795/264 concurrency now.

US 117 now ends at US 301, so no concurrency with either US 264 or I 795.

[Alps]

Not sure if it counts or not but US 460 ALT is multiplexed with I-264 through the downtown tunnel and across the Berkeley Bridge between Portsmouth and Norfolk, VA, but is not signed on the interstate

EDIT: Oh and a defunct one: I-795 and US 117 in North Carolina. IIRC 117 was recently moved back to it's original alignment.

Last I'd heard, the FHWA didn't want to let them move it back because it would be "downgrading" the road from its improved alignment.  Of course, that defeats the whole purpose of the Interstate system.  Hopefully they saw the error of their ways.

[TheStranger]

Would I-795 be only the third interstate created simply to avoid freeway-specific traffic restrictions?  (The other two being I-88 and I-335)

[agentsteel53]

Would I-795 be only the third interstate created simply to avoid freeway-specific traffic restrictions?  (The other two being I-88 and I-335)

what does this mean? 

[Alps]

Would I-795 be only the third interstate created simply to avoid freeway-specific traffic restrictions?  (The other two being I-88 and I-335)

Please elaborate.  Do you mean speed limit restrictions?

(To elaborate myself: I-678 removed restrictions on the Hutchinson River Parkway north of the Whitestone Bridge to the Bruckner Interchange in NY.  I-278 removed restrictions on the former Gowanus Parkway, now Expressway.)

[rickmastfan67]

Would I-795 be only the third interstate created simply to avoid freeway-specific traffic restrictions?  (The other two being I-88 and I-335)

Please elaborate.  Do you mean speed limit restrictions?

Trucks of a specific length couldn't use I-795 when it was only US-117.  When it became an Interstate, the restrictions were removed.

[Alps]

Would I-795 be only the third interstate created simply to avoid freeway-specific traffic restrictions?  (The other two being I-88 and I-335)

Please elaborate.  Do you mean speed limit restrictions?

Trucks of a specific length couldn't use I-795 when it was only US-117.  When it became an Interstate, the restrictions were removed.

I know in NJ, the 102", double-trailer, and Hazmat networks are assigned based on roadway, not designation.  That seems the more intelligent way to do things.

[agentsteel53]

Trucks of a specific length couldn't use I-795 when it was only US-117.  When it became an Interstate, the restrictions were removed.

wait, what?  because the number was changed, the road magically got better??

[rickmastfan67]

Trucks of a specific length couldn't use I-795 when it was only US-117.  When it became an Interstate, the restrictions were removed.

wait, what?  because the number was changed, the road magically got better??

It was some weird law in NC that effects highways that aren't on the NHS or something like that.

[froggie]

No longer existing, but from 1988 until ca. 1995, there was an I-494/US 169 duplex in Eden Prairie, MN.

Further south, there's a stretch of I-435/US 169 (with US 50 thrown in too) outside Kansas City.

Last I'd heard, the FHWA didn't want to let them move it back because it would be "downgrading" the road from its improved alignment.  Of course, that defeats the whole purpose of the Interstate system.  Hopefully they saw the error of their ways.

Not so much that, but it defeats the purpose of the U.S. highway system, to which AASHTO policy is to place "on the best roads".  Following AASHTO policy on US routes, US 117 should remain on the freeway...and not go back to its old alignment.

[agentsteel53]

It was some weird law in NC that effects highways that aren't on the NHS or something like that.

so by virtue of it being an interstate, it was automatically added to the NHS, but as a US route, it was not - despite being the exact same road?

the NHS, everybody!  your tax dollars at work ...

[froggie]

I found the relevant state statute:  Section 20-115.1

In a nutshell, state law only allows tandem-trailers and semis longer than 53ft along the Interstate system and "those sections of the federal‑aid primary system designated by the United States Secretary of Transportation."  Since FAP/FAS (Federal-Aid Primary/Federal-Aid Secondary) was effectively eliminated by ISTEA almost 20 years ago, it stands to reason that NHS routes (which are designated by FHWA) fit the bill of "federal-aid primary system designated by the US Secretary of Transportation".  Especially since NHS is, above all else, a funding category.

[agentsteel53]

In a nutshell, state law only allows tandem-trailers and semis longer than 53ft along the Interstate system and "those sections of the federal‑aid primary system designated by the United States Secretary of Transportation."  Since FAP/FAS (Federal-Aid Primary/Federal-Aid Secondary) was effectively eliminated by ISTEA almost 20 years ago, it stands to reason that NHS routes (which are designated by FHWA) fit the bill of "federal-aid primary system designated by the US Secretary of Transportation".  Especially since NHS is, above all else, a funding category.

why use funding as a criterion for road quality, though?  whether or not federal dollars were used is quite the imperfect estimate of whether a road can handle a truck longer than 53 feet.

[froggie]

Tell that to the North Carolina General Assembly...

[huskeroadgeek]

.

Further south, there's a stretch of I-435/US 169 (with US 50 thrown in too) outside Kansas City.

I'd thought about this one too, but then I remembered that it doesn't exist anymore because of a recent rerouting of US 169. Instead of turning to go south down Metcalf Av. through Overland Park and then following I-435 west to I-35, US 169 continues down Shawnee Mission Pkwy. with US 56 and US 69 to I-35 and then multiplexes with I-35 past I-435.

[Quillz]

Nevada either has, or will have, a US-395/I-580 concurrency between Carson City and Reno, but the catch is the later is technically unsigned.

[TheStranger]

Nevada either has, or will have, a US-395/I-580 concurrency between Carson City and Reno, but the catch is the later is technically unsigned.

From what I recall reading here, 580 is slated to eventually be signed, once the route from Carson City to Reno is all-freeway.  It's been on the books though for the last 30-35 years!

[mukade]

I-465 and US 421 in Indianapolis...