Fastest Speed limit on a local road / Slowest Advisory on State or National Road

[michravera]

California's CVC sections 22348-66 seem to limit the authority for counties and municipalities to post a speed limit above 65MPH. But, many, perhaps most counties and some cities in California do post 65MPH on at least some of their roads. The laws of other states, of course, differ. Do any of the states (especially here in the west), for instance, with 70-85 MPH maximum speed limits have local roads posted as high as 70MPH? Where, how, and why? Do the states give the authority to post local roads at higher speed limits as are safe and orderly?

Also, there are several advisory signs on CASR-1 that simply advise "SLOW". I also believe that there are some turns advised down to 5MPH, but I am fairly sure that I have seen 15 and even 10 on CASR-1. Notwithstanding STOP and "Go BACK" signs and barriers, what is the lowest advised speed on State or Nationally maintained roads.

International answers are welcome! If your country isn't organized into States or Cantons or Departments, you can substitute any authority below national that would seem to fit, but that includes something larger than cities or regions around a city. For instances, for the UK, I would consider England, Scotland, Wales, Northern Ireland, etc to be the equivalents of "States".

[Max Rockatansky]

I've never seen an advisory sign as low as 15 MPH on CA 1.  I have seen them though on US 191 on the Coronado Trail in Arizona.  Caltrans will usually just post a single speed limit and rarely does anything else.  Advisory signs on rural mountain roads are generally very rare to see.  Arizona and ADOT on the other hand loved to post advisory speed limits all over (and post low mountain speed limits)

[TheHighwayMan3561]

There's a 15 MPH switchback on zombie MN 101 in Chanhassen.

https://goo.gl/maps/Zac1ESDjYzt16JzW7

[1995hoo]

It helps that in Virginia the Commonwealth maintains the overwhelming majority of roads, such that secondary highways are state highways. Off the top of my head, a 5-mph advisory sign on the Snickersville Turnpike near Bluemont immediately comes to mind. The hairpin is sharp enough that trucks are not permitted.

[kphoger]

US-550 gets down to 15mph advisories, as does UT-46.

I thought it would be easy to come up with a 10mph one, but I'm struggling to.

[1995hoo]

US-550 gets down to 15mph advisories, as does UT-46.

I thought it would be easy to come up with a 10mph one, but I'm struggling to.

The Moki Dugway has a 10-mph warning sign at the bottom.

[hotdogPi]

I've posted this before, but 5 MPH on MA 28 in North Reading (gone now).

[Big John]

Do school zones count?  Wisconsin uses 15 MPH there.

[CoreySamson]

The loop ramp at the start of US-259 in Nacogdoches at its terminus with US-59 is signed at 10 mph:
https://www.google.com/maps/@31.6815031,-94.6662046,3a,24.1y,66.96h,90.94t/data=!3m6!1e1!3m4!1s2Xxzcji3nBKFGPAULWarlQ!2e0!7i13312!8i6656

Really slow for Texas, plus there's even a "your speed is" trailer to remind you of it.

[jeffandnicole]

What states in the west post 85 mph? I think we all know where the 1 instance of that is posted.

[FrCorySticha]

Really slow for Texas, plus there's even a "your speed is" trailer to remind you of it.

As the GSV car is doing 22 around 10 MPH ramp.

[sprjus4]

Local ordinance in Chesapeake, VA currently permits a speed limit of up to 65 mph on limited access highways. This was added around 2015 when the city intended to increase the speed limit from 55 mph on the VA-168 Chesapeake Expressway toll road, but never went through. So while as high as 65 mph is permitted, the highest posted locally is 55 mph. The city has 60 mph zones on I-64, I-464, and I-664 though these are maintained by VDOT.

Notwithstanding the foregoing, the director of public works or designee may increase the maximum speed limit to 65 miles per hour where indicated by lawfully placed signs, erected subsequent to a traffic engineering study and analysis of available and appropriate accident and law-enforcement data, on: (i) interstate highways, (ii) multilane, divided, limited access highways, and (iii) high-occupancy vehicle lanes if such lanes are physically separated from regular travel lanes.

https://library.municode.com/va/chesapeake/codes/code_of_ordinances?nodeId=PTIICOOR_CH74TRVE_ARTXIIIREDRSP_S74-443MASPLIGE

[WillWeaverRVA]

Henrico County, VA (which maintains all non-primary routes within its borders) has several roads posted at 55 mph. This includes South Laburnum Avenue, which is a 4- to 6-lane divided facility between US 60 and VA 5, but also Darbytown Road, which is a 2-lane rural road.

VA 150 has a couple of exits signed with 15 mph advisory speeds, but they're RIRO interchanges. However, VA 288's northbound exit for SR 720 Lucks Lane is not a RIRO interchange but is posted with a 15 mph advisory speed.

[kphoger]

What states in the west post 85 mph? I think we all know where the 1 instance of that is posted.

Only a single highway in a single state, and it's the one we all know.

[michravera]

What states in the west post 85 mph? I think we all know where the 1 instance of that is posted.

I thought that Nevada law had authorized 85 MPH, but NVDoT hadn't posted it anywhere, but I was wrong. The NRS 484B.600(e) makes 80 MPH the state maximum. A half-dozen or so states have maximum limits of 80 MPH.

[I-55]

What states in the west post 85 mph? I think we all know where the 1 instance of that is posted.

I thought that Nevada law had authorized 85 MPH, but NVDoT hadn't posted it anywhere, but I was wrong. The NRS 484B.600(e) makes 80 MPH the state maximum. A half-dozen or so states have maximum limits of 80 MPH.

And Mississippi would be another if there was a toll road anywhere within the state. Since there aren't any, it'll be stuck at 70 for now. But with the way everyone drives and the lack of actual enforcement, the limit is basically 80.

[GenExpwy]

A 10 MPH advisory on US 20A heading downhill into the village of Warsaw NY.

[stevashe]

Also, there are several advisory signs on CASR-1 that simply advise "SLOW". I also believe that there are some turns advised down to 5MPH, but I am fairly sure that I have seen 15 and even 10 on CASR-1.

I've never seen an advisory sign as low as 15 MPH on CA 1.  I have seen them though on US 191 on the Coronado Trail in Arizona.  Caltrans will usually just post a single speed limit and rarely does anything else.  Advisory signs on rural mountain roads are generally very rare to see.  Arizona and ADOT on the other hand loved to post advisory speed limits all over (and post low mountain speed limits)

Nah the OP is correct, here's a 10mph advisory on CA 1. It's even posted 15 mph in the other direction.

As for Washington, I present the only time I've seen an advisory speed warning for a turn at an intersection: on the ramp to SR 18 from I-90 WB

[vdeane]

US 44/NY 55 has a 5 mph advisory speed.  It doesn't get much slower than that.