How each state handles extremely minor highways

[kphoger]

I lived in Illinois for 19 years (1975-94), all in the Chicago metro area.  I don't remember seeing any sign that looked like that.  Are those something more recent, as in post-1994?  More downstate than in metro Chicago?  The county roads were marked with the standard pentagon County Road sign, but that was it.

1.  The larger numbers aren't used as much as they used to be.  I believe the whole FAP/FAS numbering system is now technically obsolete in Illinois, but the numbers are still shown on maps and many mile markers still remain.  On other secondaries that used to have these mile markers, though, I've seen them disappearing.

2.  The mile markers aren't posted every mile, but rather at bridges and on other sign posts and such.

3.  They are comparatively rare in Chicagoland.  Looking at the Will County map, for example, it's hard to find any that don't also carry a signed county highway or primary state highway number.

4.  However, the mile markers themselves are also used for primary state and US routes—not just secondaries.

As for secondaries, I'm more familiar with ones in southern Illinois, such as...
Herrin Road (Secondary state route 908)
Old Route 13 (Secondary state route 910)
Kinlou Road (Secondary state route 8799)
Old Highway 51 (Secondary state route 919)

[kphoger]

I lived in Illinois for 19 years (1975-94), all in the Chicago metro area.  I don't remember seeing any sign that looked like that.  Are those something more recent, as in post-1994?  More downstate than in metro Chicago?  The county roads were marked with the standard pentagon County Road sign, but that was it.

As for primaries in Chicagoland...
mile marker 9, IL-47, Kane County

[WillWeaverRVA]

Virginia also has the school routes, which are part of the secondary route system, but use one set of numbers statewide (9XXX) whereas other secondary route numbers usually repeat from county to county.

[formulanone]

Not sure if this helps, but ALDOT has a GIS layer which shows functional classification. I'm still playing around but I'm sure if this is what you're looking for. Nothing is jumping out at me as a trove of hidden routes, so make what you will. You can find whether some little bit of road is on a State System or not:

AL# (10 digits); the first six are the State Route number with zeros in front.
The seventh digit is "0" for the eastbound/northbound side, or "1" for westbound/southbound side.
Then "000" tagged onto the end.

IN# (10 digits) for interstates, basically just the same series as the state routes. The last four digits seem to follow the same patterns as above.

IV# for roads not in the state system (example, 0004520083). The IV numbers' first six digits seem to be county road numbers (or whatever), then "0" or "1" for lane of travel, and a three-digit code on the end which seems to represent the county.

Ramps are marked RP# (10 digits). Many of them seem to have 000###, then 00, and that 2-digit county code. As an example, the southbound exit side ramps are even, the southbound entrance ramp is odd. The northbound exit is even-numbered, then the following entrance ramp is odd. Sometimes they are sequential, but some ramps which opened at different times are not.

Unbuilt portions NC# (10 digits); for example, the stub of I-22 to US 31 which doesn't physically exist. The last four digits seem to follow the same patterns as RPs and IVs.

I can't figure out the "city/county" code; it's not the name numbers as the ALDOT milepost maps, and they don't correspond to the license plate county codes, either.

[ElishaGOtis]

Not sure if this helps, but ALDOT has a GIS layer which shows functional classification. So you can find whether some little bit of road is on a State System or not, and either gets an AL# (10 digits, first six is the SR#, trying to figure out the last four) or an IV# (example, 0004520083 where the last four seem to a county or city code).

I'm still playing around but I'm sure if this is what you're looking for. Nothing is jumping out at me as a trove of hidden routes, so make what you will.

I don't even think that's up to date, as it's from 2017. It's not including the new routes down in Foley, for instance...

Was only able to find this... https://aldotgis.dot.state.al.us/milepostmaps/default.htm

[hbelkins]

Actually, Kentucky has three different numbering conventions:

1.) The one-size-fits-all approach, starting with 1 and ending with whatever the number is up to now (probably in the high 3600s or low 3700s)

2.) Frontage roads are numbered 6xxx, but are mostly unsigned. There are a few signed examples in the western part of the state.

3.) The parkways that haven't yet been converted to interstates are numbered in the 9xxx series, but not signed as such.

[TheCatalyst31]

*Illinois?

Illinois has "hidden" highway numbers on state-maintained roads that aren't part of a signed numbered highway. I put hidden in quotes because the highway numbers are still visible on their mile markers, like so:

The numbering convention is a bit odd; there's a clump of numbers in the 900s, a clump in the 8000s, and a few other scattered numbers.

Indiana and Wisconsin both have mileage caps, so I imagine they usually try to foist minor highways on the county or municipality. In Wisconsin at least, there's no real intermediate step between silly minor state highways with normal numbers and stuff the state doesn't maintain, and stuff like tiny connectors don't get their own numbers.

Indiana is not up against their cap. They foist minor highways on counties and municipalities because they want to.

So stuff like the IN 28 rerouting around Tipton wasn't a desperate attempt to shed miles? Someone at INDOT has a sick mind.

[NWI_Irish96]

*Illinois?

Illinois has "hidden" highway numbers on state-maintained roads that aren't part of a signed numbered highway. I put hidden in quotes because the highway numbers are still visible on their mile markers, like so:

The numbering convention is a bit odd; there's a clump of numbers in the 900s, a clump in the 8000s, and a few other scattered numbers.

Indiana and Wisconsin both have mileage caps, so I imagine they usually try to foist minor highways on the county or municipality. In Wisconsin at least, there's no real intermediate step between silly minor state highways with normal numbers and stuff the state doesn't maintain, and stuff like tiny connectors don't get their own numbers.

Indiana is not up against their cap. They foist minor highways on counties and municipalities because they want to.

So stuff like the IN 28 rerouting around Tipton wasn't a desperate attempt to shed miles? Someone at INDOT has a sick mind.

No, and while there have been a lot of weird reroutings/truncations, you may have hit on the weirdest.

[kurumi]

Connecticut does track some numbered routes that are even more minor than the "secret" SRs and SSRs.

Here's an online map: https://maps-ctdot.hub.arcgis.com/datasets/CTDOT::ctdot-state-routes-and-local-roads/explore?layer=0&location=41.719851%2C-72.446953%2C16

If the location is right, you'll be on Connecticut State Park Route 13 in Gay City SP, Hebron.
There are also state forest and state institution, along with I, US, CT, SR, SSR - a total of 8 categories. The SI/SF/SP route numbers can duplicate those in other systems.

These numbers are minor enough that tbh I don't care about chronicling them

[ElishaGOtis]

Connecticut does track some numbered routes that are even more minor than the "secret" SRs and SSRs.

Here's an online map: https://maps-ctdot.hub.arcgis.com/datasets/CTDOT::ctdot-state-routes-and-local-roads/explore?layer=0&location=41.719851%2C-72.446953%2C16

If the location is right, you'll be on Connecticut State Park Route 13 in Gay City SP, Hebron.
There are also state forest and state institution, along with I, US, CT, SR, SSR - a total of 8 categories. The SI/SF/SP route numbers can duplicate those in other systems.

These numbers are minor enough that tbh I don't care about chronicling them

I'm trying to wrap my mind around all the different categories WTFRICC   
"State Special Service Highway" (say that 10 times fast lol)
"State Institution" (a bunch of these are restricted)
"State Park" (EVERY MINUTE DRIVEWAY HOLY MOLY  )
And more

Apparently "Connecticut Route" is different than "State Road" (see SR-514/515 in Thompsonville)