California Postmiles

[The Ghostbuster]

MOD NOTE: This post was originally made in replying to this post in the Westside Parkway/CA 58 realignment in Bakersfield thread. I thought it might generate other discussion, so split it out. –Roadfro.


Will California ever ditch the postmile system and implement a system with mileposts placed alongside the highways, like the rest of the country does? Somehow, I doubt it, but since the state first started adding exit numbers statewide in 2002, they should have posted milepost signs as well.

[cl94]

Will California ever ditch the postmile system and implement a system with mileposts placed alongside the highways, like the rest of the country does? Somehow, I doubt it, but since the state first started adding exit numbers statewide in 2002, they should have posted milepost signs as well.

Hahahahahahahaha, fat chance. In the places they have installed MUTCD-standard mileposts, said mileposts use...county mileage.

[cahwyguy]

Will California ever ditch the postmile system and implement a system with mileposts placed alongside the highways, like the rest of the country does? Somehow, I doubt it, but since the state first started adding exit numbers statewide in 2002, they should have posted milepost signs as well.

The simple answer is "no". The postmiles have a number of reasons for being retained: It provides a unique address for EVERYTHING on the highway within their digitized linear reference system; it doesn't require extensive reworking when a road is realigned or extended on either end (unlike posted mileposts). There is a statewide odometer. We go into this in great detail in the interview in our episode on state highway numbering, CARxR 1.07: Highway Numbering: State Highways and Post Miles, https://caroutebyroute.org/2023/01/16/carxr-1-07-highway-numbering-state-highways-and-post-miles/  See also https://postmile.dot.ca.gov/PMQT/documents/CALTRANS%20POSTMILE%20SYSTEM%20061016.pdf

[Max Rockatansky]

The mistake people often make with Postmiles is assuming they intended for use for the average driver like mile markers are.  Like Daniel said, Postmiles provide addresses along State Highways which is intended mostly for use by Caltrans or other agencies.  As an example, I've found that if I given CHP a Postmile address they tend be able to dispatch with far more accuracy. 

That's not say I don't think there shouldn't be mile markers, they just serve different purpose than Postmiles.  Ideally I would like to see both in place.  I do agree with cl94 that having the mile markers based on the County is of limited use. 

[cl94]

That's not say I don't think there shouldn't be mile markers, they just serve different purpose than Postmiles.  Ideally I would like to see both in place.

Which is effectively the system NY has in place with its reference markers along freeways with normal mileposts, and to a lesser extent Nevada and Ohio along freeways with both postmiles and mile markers. Postmiles are for maintenance and emergency services, not the average driver. Though NV has been revising the postmile system to make more sense to your typical driver.

[Rothman]

That's not say I don't think there shouldn't be mile markers, they just serve different purpose than Postmiles.  Ideally I would like to see both in place.

Which is effectively the system NY has in place with its reference markers along freeways with normal mileposts, and to a lesser extent Nevada and Ohio along freeways with both postmiles and mile markers. Postmiles are for maintenance and emergency services, not the average driver. Though NV has been revising the postmile system to make more sense to your typical driver.

Just wait until the transition is complete to GIS milepoints...

[skluth]

That's not say I don't think there shouldn't be mile markers, they just serve different purpose than Postmiles.  Ideally I would like to see both in place.

Which is effectively the system NY has in place with its reference markers along freeways with normal mileposts, and to a lesser extent Nevada and Ohio along freeways with both postmiles and mile markers. Postmiles are for maintenance and emergency services, not the average driver. Though NV has been revising the postmile system to make more sense to your typical driver.

Just wait until the transition is complete to GIS milepoints...

That will be just grand, calling 911 and saying "My car is stuck on the tracks at 34.1968319 North -119.142252 West. Hurry!!!!"

[roadfro]

Will California ever ditch the postmile system and implement a system with mileposts placed alongside the highways, like the rest of the country does? Somehow, I doubt it, but since the state first started adding exit numbers statewide in 2002, they should have posted milepost signs as well.

The whole rest of the country doesn't use just mileposts. Nevada uses the a similar system as California postmiles (just without letter prefixes for realignments, etc.), but NDOT refers to their county-based system as "mileposts". NDOT uses both county and state-wide MUTCD mileposts on Interstate Highways though.

Although I do agree Caltrans should consider traditional mileposts as well, at least on Interstate and US Highways.

NDOT took a different approach, and on state and US highways, now employs enhanced mileposts (similar to enhanced MUTCD mileposts) with shield, that are larger and meant to be seen by the traveling public.

[kphoger]

I do agree with cl94 that having the mile markers based on the County is of limited use. 

Especially in a place like Kentucky, which is approximately twice the size of San Bernardino County (CA) but has 120 counties.

[cl94]

I do agree with cl94 that having the mile markers based on the County is of limited use. 

Especially in a place like Kentucky, which is approximately twice the size of San Bernardino County (CA) but has 120 counties.

Georgia and Ohio also love their county mileposts. Ohio even has county exit numbers on some non-Interstate freeways.

NDOT took a different approach, and on state and US highways, now employs enhanced mileposts (similar to enhanced MUTCD mileposts) with shield, that are larger and meant to be seen by the traveling public.

There's a standards document to determine what gets an enhanced milepost and what doesn't. Basically, rural gets them and urban does not. Sample size for unsigned routes is too small right now to say if they'll be crazy enough to put an EMM on SR 705 et al, but they have been crazy enough to put them on SR 877 and, indeed, that's one of the few places they exist near Reno. Other NDOT districts seem to be a little faster with the uptake.

I am very interested to see what happens with the upcoming US 395 project north of I-80 and any other non-I freeways that get built, such as the 395-445 connector and 395 upgrade/bypass south of Carson. Will those get the white "enhanced postmiles" or will they get the green "enhanced reference panels" Interstates get? I'm never on 395 north of 80, but I want to say that lacks anything more than standard mileposts.

[roadfro]

NDOT took a different approach, and on state and US highways, now employs enhanced mileposts (similar to enhanced MUTCD mileposts) with shield, that are larger and meant to be seen by the traveling public.

There's a standards document to determine what gets an enhanced milepost and what doesn't. Basically, rural gets them and urban does not. Sample size for unsigned routes is too small right now to say if they'll be crazy enough to put an EMM on SR 705 et al, but they have been crazy enough to put them on SR 877 and, indeed, that's one of the few places they exist near Reno. Other NDOT districts seem to be a little faster with the uptake.

I am very interested to see what happens with the upcoming US 395 project north of I-80 and any other non-I freeways that get built, such as the 395-445 connector and 395 upgrade/bypass south of Carson. Will those get the white "enhanced postmiles" or will they get the green "enhanced reference panels" Interstates get? I'm never on 395 north of 80, but I want to say that lacks anything more than standard mileposts.

That policy document is fairly new–circa 2014, given the date of this thread. As a result, the enhanced milepost and enhanced reference panels are not deployed at all locations. Most have been installed concurrent with other construction projects–lately, if an NDOT road gets resurfaced (especially rural highways), it's getting new mileposts installed in conformance with this policy document.

There is currently nothing more than regular mileposts on US 395 north of I-80. However, I believe some of these between I-80 and the Bus 395/Panther Valley were curiously labeled as "IR 580" years before I-580 was posted, even though that stretch has never been part of I-580–this corresponds with many of the old panels that had been along Virginia St/SR 430 being labeled as "US 395", likely from the pre-freeway days and never remeasured. (Urban mileposts are often neglected by NDOT, so not sure how many of these are still kicking.)

With the upcoming 395 project, there will likely be brand new standard mileposts installed, but not enhanced markers–based purely on the policy. But I'm curious what the posted county mileage will be along 395, given routing changes (freeway through Reno and Washoe Valley), old US 395/SR 430 is mostly out of NDOT control now (and much of it that is not has been re-branded as US 395A in south Reno), and the now-signed I-580/US 395 overlap.

[cl94]

There are a shocking amount of US 395 mileposts remaining on South Virginia Street, despite several of these locations not carrying US 395 for over 30 years. As well as a single US 395 shield just south of Patriot, though that may be erroneous. While NDOT often redoes mileage when a reroute occurs, they don't strip downloaded roads.

[Max Rockatansky]

There are a shocking amount of US 395 mileposts remaining on South Virginia Street, despite several of these locations not carrying US 395 for over 30 years. As well as a single US 395 shield just south of Patriot, though that may be erroneous. While NDOT often redoes mileage when a reroute occurs, they don't strip downloaded roads.

Caltrans is inconsistent removing Postmile paddles.  I know of a bunch of for Route 180 on Kings Canyon Road in Fresno.  Compare that to the likes of D7 and former Route 187 where you won't find any leftovers.

[oscar]

Caltrans is inconsistent removing Postmile paddles.  I know of a bunch of for Route 180 on Kings Canyon Road in Fresno.  Compare that to the likes of D7 and former Route 187 where you won't find any leftovers.

If there were any pre-relinquishment. Postmiles aren't that common in urban areas in California.

[roadfro]

There are a shocking amount of US 395 mileposts remaining on South Virginia Street, despite several of these locations not carrying US 395 for over 30 years. As well as a single US 395 shield just south of Patriot, though that may be erroneous. While NDOT often redoes mileage when a reroute occurs, they don't strip downloaded roads.

In some spots as Virginia Street (old US 395/SR 430) was being relinquished, they put blank white adhesive over the road type & number, but otherwise left the mileposts adhered to traffic signal poles in place. Example at Plumb Lane.

Sometimes, mileposts do get removed. Sometimes, they just yank the shields (assuming route shields were posted to begin with).

[Max Rockatansky]

Caltrans is inconsistent removing Postmile paddles.  I know of a bunch of for Route 180 on Kings Canyon Road in Fresno.  Compare that to the likes of D7 and former Route 187 where you won't find any leftovers.

If there were any pre-relinquishment. Postmiles aren't that common in urban areas in California.

Could be a D6 phenomenon I'm seeing.  I've generally found a decent amount of urban Postmile paddles on D6 maintained urban state highways.

[brad2971]

NDOT took a different approach, and on state and US highways, now employs enhanced mileposts (similar to enhanced MUTCD mileposts) with shield, that are larger and meant to be seen by the traveling public.

There's a standards document to determine what gets an enhanced milepost and what doesn't. Basically, rural gets them and urban does not. Sample size for unsigned routes is too small right now to say if they'll be crazy enough to put an EMM on SR 705 et al, but they have been crazy enough to put them on SR 877 and, indeed, that's one of the few places they exist near Reno. Other NDOT districts seem to be a little faster with the uptake.

I am very interested to see what happens with the upcoming US 395 project north of I-80 and any other non-I freeways that get built, such as the 395-445 connector and 395 upgrade/bypass south of Carson. Will those get the white "enhanced postmiles" or will they get the green "enhanced reference panels" Interstates get? I'm never on 395 north of 80, but I want to say that lacks anything more than standard mileposts.

That policy document is fairly new–circa 2014, given the date of this thread. As a result, the enhanced milepost and enhanced reference panels are not deployed at all locations. Most have been installed concurrent with other construction projects–lately, if an NDOT road gets resurfaced (especially rural highways), it's getting new mileposts installed in conformance with this policy document.

There is currently nothing more than regular mileposts on US 395 north of I-80. However, I believe some of these between I-80 and the Bus 395/Panther Valley were curiously labeled as "IR 580" years before I-580 was posted, even though that stretch has never been part of I-580–this corresponds with many of the old panels that had been along Virginia St/SR 430 being labeled as "US 395", likely from the pre-freeway days and never remeasured. (Urban mileposts are often neglected by NDOT, so not sure how many of these are still kicking.)

With the upcoming 395 project, there will likely be brand new standard mileposts installed, but not enhanced markers–based purely on the policy. But I'm curious what the posted county mileage will be along 395, given routing changes (freeway through Reno and Washoe Valley), old US 395/SR 430 is mostly out of NDOT control now (and much of it that is not has been re-branded as US 395A in south Reno), and the now-signed I-580/US 395 overlap.

I appreciate the explanation on Nevada DOT's county mileposts. But you'd have to agree that following that policy to the letter has some fairly absurd results. Such as this one in Fernley: https://www.google.com/maps/@39.6057928,-119.2510554,3a,15y,14.92h,89.51t/data=!3m6!1e1!3m4!1sN840QDovp0pdWpX-6aqcvQ!2e0!7i16384!8i8192

Not to mention the fact that NDOT mileposts the US 6-95 combination northwest of Tonopah as US 6, even though the design of the road clearly indicates that it should be mileposted as US 95.

[jdbx]

The mistake people often make with Postmiles is assuming they intended for use for the average driver like mile markers are.  Like Daniel said, Postmiles provide addresses along State Highways which is intended mostly for use by Caltrans or other agencies.  As an example, I've found that if I given CHP a Postmile address they tend be able to dispatch with far more accuracy. 

That's not say I don't think there shouldn't be mile markers, they just serve different purpose than Postmiles.  Ideally I would like to see both in place.  I do agree with cl94 that having the mile markers based on the County is of limited use. 

I had a similar experience once when I was driving in rural Napa County on CA-128. I came around a bend and saw a motorcycle laying in the ditch, so I pulled over to investigate and saw a rider down the ravine calling for help. I shouted that I was going to call for rescue, and luckily there was a postmile a few yards up the road that I could reference.

[pderocco]

Just wait until the transition is complete to GIS milepoints...

That will be just grand, calling 911 and saying "My car is stuck on the tracks at 34.1968319 North -119.142252 West. Hurry!!!!"

Supposedly, cell phones are supposed to report your location when you call 911. The only time I ever called 911, I asked, and they had no idea where I was.

[kphoger]

Supposedly, cell phones are supposed to report your location when you call 911. The only time I ever called 911, I asked, and they had no idea where I was.

If your cell phone carrier is unable to determine your phone's exact location during the call, then they will be unable to supply that information when requested by 911 dispatch.  But, even if they are able to determine it to some degree of accuracy, that doesn't mean the info is sent to 911 dispatch in a split-second:  sometimes the process takes a while.

[roadfro]

I appreciate the explanation on Nevada DOT's county mileposts. But you'd have to agree that following that policy to the letter has some fairly absurd results. Such as this one in Fernley: https://www.google.com/maps/@39.6057928,-119.2510554,3a,15y,14.92h,89.51t/data=!3m6!1e1!3m4!1sN840QDovp0pdWpX-6aqcvQ!2e0!7i16384!8i8192

Not to mention the fact that NDOT mileposts the US 6-95 combination northwest of Tonopah as US 6, even though the design of the road clearly indicates that it should be mileposted as US 95.

The only thing absurd in that link is that NDOT erroneously used "US 50A" and "US 95A" shields instead of properly marking "ALT US 50" and "ALT US 95"


While not explicitly stated in that previously-linked document, NDOT follows a policy that the lowest numbered route gets mileposting preference where US routes overlap. That's consistent with how routes are inventoried in their State Maintained Highways book as well as with MUTCD policy on reference panel/exit number continuity.

That appears to be the situation in both cases you bring up–the road is mileposted under the less commonly known/traveled number of the multiplex.