Non-isolated state routes that do not intersect any other state maintained route

[empirestate]

NY 171 crosses NY 5S on an overpass, but here is no interchange, and that's the only place it has any contact with another state route.  NY 878 has two sections that don't connect, and one of them does not intersect any other state routes.  There's also the formerly unsigned NY 25C, which is now signed again due to a contractor error, so if you count that, then that's another one.

That part of NY 878 intersects Seagirt Blvd., which is a state reference route, discretely (and discreetly) numbered 901C. So I guess that doesn't count, since from the OP's example we are definitely including unsigned routes. Thus, of course, "NY 25C" would indeed count as well, as would quite a few other reference routes around the state.

[national highway 1]

US 160 cuts across the NW corner of New Mexico, and is the only road that connects to NM 597, the road to the Four Corners monument.

NM 597 would not count, because US 160 is a state (maintained) route.

Both of them do not connect with any other highways in New Mexico.

[CNGL-Leudimin]

Since almost every damn numbered road classed as a state road and above is effectively a state (maintained) road, the winner is I-15 in Arizona .

[hotdogPi]

Since almost every damn numbered road classed as a state road and above is effectively a state (maintained) road, the winner is I-15 in Arizona .

Wrong. It touches I-15 in Nevada and I-15 in Utah.

(Still, it's one single route, not split up by state.)

[NWI_Irish96]

None as of now in Indiana, but with all the decommissioning/truncating they are doing, there might eventually be one.

[Mapmikey]

Maryland used to have a bunch of floating routes like this but not so many now.

MD 125 comes to mind immediately as one still in place...

Mike

[hbelkins]

"Floating routes." That's a good way to describe them.

[roadfro]

Two come to mind for Nevada:

SR 705 - Clear Creek Road near Carson City. The whole road used to be part of the Lincoln Highway south branch heading up to Lake Tahoe, and later became US 50 (since moved to the current alignment). The portions of the road that lie within Carson City have been turned over to the city for maintenance. However, a 1-mile section of the road dips into Douglas County–this section is still maintained as SR 705 (unsigned), and is thus isolated from the rest of the state highway system.

SR 781 - Palisades Bridge. This one is out in the middle of nowhere in Eureka County. It consists solely of a 0.039-mile bridge over the Humboldt River near the townsite of Palisades. It is only a state highway because NDOT maintains the bridge–I'm not sure if the connecting road was ever a state highway or not.

[TheOneKEA]

Maryland used to have a bunch of floating routes like this but not so many now.

MD 125 comes to mind immediately as one still in place...

Mike

MD 125 is the only main sequence route I can think of that is still a floating route, there are lots of secondary routes like MD 854 that are also floating routes.

[odditude]

Based on some wiki research:
NJ 13, 64, and 162 are floaters, being state-maintained portions of 600-series county roads containing bridges.
Also, NJ 152 and NJ 161 both terminate on 600-series roads and seem to be little more than historical oddities.

[empirestate]

NJ 13, 64, and 162 are floaters, being state-maintained portions of 600-series county roads containing bridges.

Oodles of those along PA's quadrant routes as well. Far too many to list.


iPhone

[Duke87]

In New Jersey, NJ 13, NJ 64, and NY 152 come to mind, although the first of these is unsigned.  In Connecticut, I'm pretty sure that there aren't any.

NJ 161 is also Orphaned. And NJ 64 is supposed to be unsigned, it only appears on a single street sign blade because someone goofed.

As for Connecticut, there are no signed orphans. There historically were a few unsigned orphans, I'm not sure if any remain.

[SteveG1988]

NJ 324, unsigned but it connects to no state routes.

[jwolfer]

The eastern part of Florida SR 2 in Baker and Columbia Counties is completely isolated from the rest of the Florida state highway system. It connects 2 sections of Georgia SR 94. It intersects with Baker CR 125

[hotdogPi]

The eastern part of Florida SR 2 in Baker and Columbia Counties is completely isolated from the rest of the Florida state highway system. It connects 2 sections of Georgia SR 94. It intersects with Baker CR 125

It touches Georgia SR 94, which is a state route. Therefore, it doesn't count.

[hbelkins]

Come to think of it, there are a number of these on Kentucky's system. Just about every county road bridge over an interstate or parkway has a hidden inventory number. They aren't signed, but they're marked on official county maps.

[cl94]

The aforementioned NY 171 is the only such signed case in New York.

If we're including reference routes:
*NY 920T in Canajoharie. Short section of a village street.
*NY 921F in Marcy. This one is a dead-end road that does little more than serve a parking lot along the Mohawk River. Might win the award for stupidest NY route.
*NY 900W in Southhampton (short segment of Montauk Highway)

I'm not including reference routes not maintained by NYSDOT, such as NY 900J (Cross Bay Veterans Memorial Bridge), as these maintain a number solely for inventory purposes.

[Rover_0]

Many of the (oft unsigned) Utah state routes serving state parks and institutions qualify.

UT-303: Serves Goblin Valley SP, county roads connect it to UT-24

UT-304: The shortest Utah state route at .086 miles (454 ft) at Hyrum SP. It is the Hyrum Reservoir access road and ends at the 300 South/400 West intersection in Hyrum.

UT-309: Millsite SP. It begins at Ferron Canyon Rd and runs north for about .357 mi (about 1885 ft)

UT-312: Willard Bay SP. It begins at 2000 W in southern Box Elder County and serves the south marina.

There are a number of former routes (305 at Big Sandy Reservoir, 308 at Kodachrome SP) that also don't intersect any other state routes.

[cpzilliacus]

North Carolina State Route 128 ---- I was just on this road yesterday!!!  Goes to the top of Mount Mitchell, only road it intersects with is the Blue Ridge Parkway, which I don't think is part of the NC State Highway System (I think???)

Not sure if it is technically considered part of the NCDOT network or not, but it is owned and maintained by the National Park Service.

[jwolfer]

The eastern part of Florida SR 2 in Baker and Columbia Counties is completely isolated from the rest of the Florida state highway system. It connects 2 sections of Georgia SR 94. It intersects with Baker CR 125

It touches Georgia SR 94, which is a state route. Therefore, it doesn't count.

It is isolated from the Florida SR system.   Your original posting is unclear that other states SR intersections would disqualify. So sorry for my misunderstanding

[jwolfer]

The eastern part of Florida SR 2 in Baker and Columbia Counties is completely isolated from the rest of the Florida state highway system. It connects 2 sections of Georgia SR 94. It intersects with Baker CR 125

It touches Georgia SR 94, which is a state route. Therefore, it doesn't count.

I did state that in my post. The original post was not clear that touching other state's SR was a disqualifier.  So sorry for my misunderstanding interpretation

[hbelkins]

Touching another state's route would not be a disqualifier (states the OP in this thread). Otherwise, WV 102 would count because it connects only to VA 102. I don't think there are any WV county routes (technically state-maintained) that connect WV 102 to US 52.

[Bitmapped]

Touching another state's route would not be a disqualifier (states the OP in this thread). Otherwise, WV 102 would count because it connects only to VA 102. I don't think there are any WV county routes (technically state-maintained) that connect WV 102 to US 52.

CR 52/6 intersects both WV 102 and US 52.