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NY - Sequential vs. Mile Based Exits

Started by Buffaboy, January 25, 2018, 02:38:55 AM

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machias

Quote from: empirestate on January 30, 2018, 05:44:45 PM
Quote from: 1 on January 30, 2018, 09:08:44 AM
Quote from: empirestate on January 30, 2018, 09:07:57 AM
Quote from: upstatenyroads on January 25, 2018, 10:08:13 PM
Quote from: Rothman on January 25, 2018, 09:21:51 AM
The funny thing is that when there was an upswell to switch over at NYSDOT some years ago, a rather...singularly intelligent... office director suggested NEW EXIT XX signage, I kid you not.

I remember hearing that and discussing it with some folks I know in NYSDOT. Wasn't that plan to post NEW EXIT XX for like 5 years and then switch them around and post FORMERLY EXIT XX for the next five or something like that?

Heck, why not just name the interchanges instead of numbering them? Seems like it would be a lot easier to keep the designations unique, and it probably matches more closely the way we actually navigate these days.


iPhone

Then we can't estimate how far away the exit is.

Okay, I accept that condition. Names it is! :-D

(Kidding aside, the Thruway already indicates the distance to the next exit, so that problem is easily solved.)


iPhone

No, because when you're off the side of the road in a blinding snowstorm in Upstate New York near milepost 200, you don't really know how close you are to the next exit when they're named or numbered sequentially, whereas if you know Little Falls is Exit 210, you know that you're 10 miles from the next exit.


kalvado

Quote from: upstatenyroads on January 31, 2018, 01:20:14 PM
No, because when you're off the side of the road in a blinding snowstorm in Upstate New York near milepost 200, you don't really know how close you are to the next exit when they're named or numbered sequentially, whereas if you know Little Falls is Exit 210, you know that you're 10 miles from the next exit.
And that information is helpful because... ? AAA will not bill you for excess towing mileage if there closest approved repair shop is further than default tow distance.
BTW, how did you manage to find a milepost in a blinding snowstorm to begin with?


webny99

Quote from: kalvado on January 31, 2018, 01:40:29 PM
BTW, how did you manage to find a milepost in a blinding snowstorm to begin with?

Probably using your eyes, same way you find mileposts in July  :clap:

kalvado

Quote from: webny99 on January 31, 2018, 01:54:08 PM
Quote from: kalvado on January 31, 2018, 01:40:29 PM
BTW, how did you manage to find a milepost in a blinding snowstorm to begin with?

Probably using your eyes, same way you find mileposts in July  :clap:
Well, getting out of a warm car and walking in a blinding snowstorm to the nearest milepost?...OK..
Do you always have a pen and a piece of paper in a car?

webny99

#29
Quote from: kalvado on January 31, 2018, 03:20:42 PM
Do you always have a pen and a piece of paper in a car?

Maybe I'm unique, in that I have the mental capacity to store a three or four digit number within the confines of my brain for as long as necessary :biggrin:

Anyways, this is going nowhere, so I'm out.

kalvado

Quote from: webny99 on January 31, 2018, 03:44:02 PM
Quote from: kalvado on January 31, 2018, 03:20:42 PM
Do you always have a pen and a piece of paper in a car?

Maybe I'm unique, in that I have the mental capacity to store a three or four digit number within the confines of my brain for as long as necessary :biggrin:

Anyways, this is going nowhere, so I'm out.
No, I am thinking about writing a will before venturing from warm car into the blinding blizzard on a remote highway... Or maybe you would like to write a last note to your loved ones? That would be a nice touch... 
Common recommendation is not to walk away from the broken car on a highway, especially in those conditions as getting lost and freezing is quite easy.

vdeane

You don't remember the last milepost you passed when you drive?  I always know within 2-5 miles whenever I'm on a road that had visible mile markers posted.
Please note: All comments here represent my own personal opinion and do not reflect the official position of NYSDOT or its affiliates.

kalvado

Quote from: vdeane on January 31, 2018, 07:12:03 PM
You don't remember the last milepost you passed when you drive?  I always know within 2-5 miles whenever I'm on a road that had visible mile markers posted.
5 miles is a good approximation for duration of trip, but pretty much useless in the situation we're talking about ("car went off road in blinding blizzard") - especially since mileposts often covered with snow in such weather. Walking to nearest exit, especially if exit ramp is not clearly visible, is quite dangerous in a good weather - and almost a suicide in a blizzard.
Talking with 911 dispatcher,  "past Warrensburg exit" or "past exit 19" is probably better than "milepost 65" - and GPS coordinate may be the ultimate option.

What happened here basically, is that "it is a safety issue!" card was pulled. OK, fine, it is a good argument - IF safety aspect can be proven. If not, we have a boy who cried "wolf".

vdeane

Well, you'd be able to say "10 miles from exit XX" just "before exit XX", so that would be more specific.  Also, it was never specified if the car spun out or was just pulled off on the shoulder due to poor conditions.

On another note, it does surprise me how few dispatchers know mileposts.  You'd think AAA/911 would be fluent in mileposts and reference markers.  I'm usually able to give my location in more precise terms than the dispatchers can understand.
Please note: All comments here represent my own personal opinion and do not reflect the official position of NYSDOT or its affiliates.

Duke87

I was taught it's a good idea to report your location via a mile marker if you're in distress in a rural area. This identifies your location very specifically, and is legitimately helpful - if they know you're at MM 227 and they get on going west at Exit 234, they know they can floor it for six miles before they need to slow down and start looking for you. Or they might even realize it's easier to get on going east at exit 225 and then U-turn to get to you. If all they know is "I'm heading westbound and somewhere past exit 234", they have to expend more time and effort finding you since they only have a vaguer idea of your whereabouts.

Meanwhile the benefit of this is reduced if the exit numbers don't match the mile markers. In a sequential system it's a lot more difficult for the dispatcher to determine that MM 227 is 2 miles east of exit 53 and 7 miles west of exit 54.

If you always take the same road, you will never see anything new.

Buffaboy

I wish there was an option in Google Maps that turns mike markers on, to the tenth. Ironically, I have more experience counting the milepost stones along the CSX mainline from a train window than accurately following along with mileposts on state and US highways.
What's not to like about highways and bridges, intersections and interchanges, rails and planes?

My Wikipedia county SVG maps: https://commons.wikimedia.org/wiki/User:Buffaboy

SignBridge

Mileage based and sequential exit numbering each have their pros and cons. While mileage based numbering is useful for the reasons already described, in a way it defeats the purpose of sequential exit numbering where you know that Exit-10 is the next after after Exit-9, etc. Sequential numbering seems more logical to me because skipping numbers destroys the whole concept of numbering the exits in the first place.

But again, it's pros and cons and whichever concept you feel is more useful. 

webny99

Quote from: SignBridge on January 31, 2018, 09:49:45 PM
While mileage based numbering is useful for the reasons already described, in a way it defeats the purpose of sequential exit numbering where you know that Exit-10 is the next after after Exit-9, etc.

If you're a roadgeek, you should also know that Exit 117 is next after Exit 106, etc.  :)

It also depends on your reasoning for why exits are numbered in the first place. Number order tends to be more valuable in urban areas, mileage based in rural areas.

Rothman

#38
Quote from: SignBridge on January 31, 2018, 09:49:45 PM
Mileage based and sequential exit numbering each have their pros and cons. While mileage based numbering is useful for the reasons already described, in a way it defeats the purpose of sequential exit numbering where you know that Exit-10 is the next after after Exit-9, etc. Sequential numbering seems more logical to me because skipping numbers destroys the whole concept of numbering the exits in the first place.

But again, it's pros and cons and whichever concept you feel is more useful.
I find useful information in mileage-based exit numbers, whereas sequential exit numbering is just dogmatic.
Please note: All comments here represent my own personal opinion and do not reflect the official position(s) of NYSDOT.

Alps

Quote from: SignBridge on January 31, 2018, 09:49:45 PM
Mileage based and sequential exit numbering each have their pros and cons. While mileage based numbering is useful for the reasons already described, in a way it defeats the purpose of sequential exit numbering where you know that Exit-10 is the next after after Exit-9, etc. Sequential numbering seems more logical to me because skipping numbers destroys the whole concept of numbering the exits in the first place.

But again, it's pros and cons and whichever concept you feel is more useful. 
What is the use of knowing that 10 comes after 9 if you don't know where it is? What if there's a 9A? There is truly no use and that's why it has been eliminated by the MUTCD.

empirestate

Quote from: upstatenyroads on January 31, 2018, 01:20:14 PM
Quote from: empirestate on January 30, 2018, 05:44:45 PM
Quote from: 1 on January 30, 2018, 09:08:44 AM
Quote from: empirestate on January 30, 2018, 09:07:57 AM
Quote from: upstatenyroads on January 25, 2018, 10:08:13 PM
Quote from: Rothman on January 25, 2018, 09:21:51 AM
The funny thing is that when there was an upswell to switch over at NYSDOT some years ago, a rather...singularly intelligent... office director suggested NEW EXIT XX signage, I kid you not.

I remember hearing that and discussing it with some folks I know in NYSDOT. Wasn't that plan to post NEW EXIT XX for like 5 years and then switch them around and post FORMERLY EXIT XX for the next five or something like that?

Heck, why not just name the interchanges instead of numbering them? Seems like it would be a lot easier to keep the designations unique, and it probably matches more closely the way we actually navigate these days.


iPhone

Then we can't estimate how far away the exit is.

Okay, I accept that condition. Names it is! :-D

(Kidding aside, the Thruway already indicates the distance to the next exit, so that problem is easily solved.)


iPhone

No, because when you're off the side of the road in a blinding snowstorm in Upstate New York near milepost 200, you don't really know how close you are to the next exit when they're named or numbered sequentially, whereas if you know Little Falls is Exit 210, you know that you're 10 miles from the next exit.

Well, even so, I'll willingly accept that trade-off, if naming interchanges proves to be a better means of identifying them.

Quote from: webny99 on January 31, 2018, 09:58:19 PM
It also depends on your reasoning for why exits are numbered in the first place. Number order tends to be more valuable in urban areas, mileage based in rural areas.

Exactly. I guess the part I don't get is, who says that indicating distance has to be a characteristic of the system that identifies interchanges? We already have mile markers for that.

Rothman



Quote from: empirestate on January 31, 2018, 10:16:48 PM

Quote from: webny99 on January 31, 2018, 09:58:19 PM
It also depends on your reasoning for why exits are numbered in the first place. Number order tends to be more valuable in urban areas, mileage based in rural areas.

Exactly. I guess the part I don't get is, who says that indicating distance has to be a characteristic of the system that identifies interchanges? We already have mile markers for that.

FHWA in the MUTCD.

Most people use route number/street name or exit number to indicate where to get on and off a highway.  Using mileage-based exit numbering adds another level of information to the exit number.  Sequential doesn't do that, naming interchanges is a step removed even from that.

FHWA should have branded mileage-based exit numbers as smart numbering. :D
Please note: All comments here represent my own personal opinion and do not reflect the official position(s) of NYSDOT.

webny99

Quote from: empirestate on January 31, 2018, 10:16:48 PM
Quote from: webny99 on January 31, 2018, 09:58:19 PM
It also depends on your reasoning for why exits are numbered in the first place. Number order tends to be more valuable in urban areas, mileage based in rural areas.

Exactly. I guess the part I don't get is, who says that indicating distance has to be a characteristic of the system that identifies interchanges? We already have mile markers for that.

To answer literally, the MUTCD says so  :-P

Of course, based on the assumption that the only objective of a numbering system is to identify interchanges, then the specifics of that system hardly matter to the average motorist. We might as well use random letters for each exit, or names as you suggested upthread, or different colors for each exit tab  ;-)

However, this assumption overlooks the secondary objective(s) of exit numbering - to aid the motorist in calculating the distance to their destination, to signify the location of an exit, the location of an exit within a state, the distance until the next turn or major junction, and so on.

In the eyes of many (if not most) roadgeeks, the system used should be the one that provides the best combination of valuable information, simplicity, and message clarity. Given the options, mileage-based provides by far the most external information to the motorist in the most non-intrusive way possible. As such, it is the way forward :thumbsup:

Buffaboy

Quote from: Alps on January 31, 2018, 10:02:57 PM
Quote from: SignBridge on January 31, 2018, 09:49:45 PM
Mileage based and sequential exit numbering each have their pros and cons. While mileage based numbering is useful for the reasons already described, in a way it defeats the purpose of sequential exit numbering where you know that Exit-10 is the next after after Exit-9, etc. Sequential numbering seems more logical to me because skipping numbers destroys the whole concept of numbering the exits in the first place.

But again, it's pros and cons and whichever concept you feel is more useful. 
What is the use of knowing that 10 comes after 9 if you don't know where it is? What if there's a 9A? There is truly no use and that's why it has been eliminated by the MUTCD.

Good point. Exit 57 and Exit 57a are 8 miles apart, while Exit 50 and Exit 50a are a stone's throw apart.
What's not to like about highways and bridges, intersections and interchanges, rails and planes?

My Wikipedia county SVG maps: https://commons.wikimedia.org/wiki/User:Buffaboy

empirestate

Quote from: Rothman on January 31, 2018, 10:50:21 PM


Quote from: empirestate on January 31, 2018, 10:16:48 PM

Quote from: webny99 on January 31, 2018, 09:58:19 PM
It also depends on your reasoning for why exits are numbered in the first place. Number order tends to be more valuable in urban areas, mileage based in rural areas.

Exactly. I guess the part I don't get is, who says that indicating distance has to be a characteristic of the system that identifies interchanges? We already have mile markers for that.

FHWA in the MUTCD.

Good. And why, in their view, does the distance itself have to be the identifying mark, rather than being an additional piece of information?

QuoteMost people use route number/street name or exit number to indicate where to get on and off a highway.  Using mileage-based exit numbering adds another level of information to the exit number.  Sequential doesn't do that, naming interchanges is a step removed even from that.

But why just the one? Because neither option solves the specific problem we're looking at here, where different interchanges aren't identified uniquely using numbers alone, because we have overlapping and contradictory jurisdictions and nomenclatures. Why give only the interchange's distance on signs? Why not identify it using its name, and give its location by indicating which milepost it's at?

Quote from: webny99 on January 31, 2018, 11:17:39 PM
In the eyes of many (if not most) roadgeeks, the system used should be the one that provides the best combination of valuable information, simplicity, and message clarity. Given the options, mileage-based provides by far the most external information to the motorist in the most non-intrusive way possible. As such, it is the way forward :thumbsup:

But again, remember that we're addressing the specific problem of overlapping systems (I-90, I-87, Thruway, Northway, etc.).

Also, if the most information is the best choice, why leave some out? Why not say "The Circleville Interchange, which is at milepost 226" rather than "Exit 226, which is at milepost 226"? It seems that the first way gives the most information, not the second, and thus is actually "the way forward".

webny99

Quote from: empirestate on February 01, 2018, 08:10:25 AM
And why, in their view, does the distance itself have to be the identifying mark, rather than being an additional piece of information?

Because, as I said upthread, using a distance-based system gives the motorist the most possible information in the most non-intrusive way possible. It seems you're assuming that identification is the only purpose to a numbering system, which is far from the case.


QuoteWhy not identify it using its name, and give its location by indicating which milepost it's at?

Because, how is the average joe-bloe traveler going to know what milepost their exit is at? They aren't, and as such, they won't be able to figure out as specifically how far away it is.

Quote
Also, if the most information is the best choice, why leave some out? Why not say "The Circleville Interchange, which is at milepost 226" rather than "Exit 226, which is at milepost 226"? It seems that the first way gives the most information, not the second, and thus is actually "the way forward".

Because again, the motorist will have no way of knowing the milepost of a given interchange. If you happen to already know that, then that's all well and fine, but long-distance or out-of-state travelers are highly unlikely to learn/memorize all that.

At least in my opinion, naming would add another level of confusion; as it is certainly information, I fail to see where it is information that will actually help the motorist in reaching their destination, calculating remaining distances, etc. And, as it's not strictly necessary information, it might be on the border of information overload for the average motorist.

J N Winkler

Quote from: empirestate on February 01, 2018, 08:10:25 AMExactly. I guess the part I don't get is, who says that indicating distance has to be a characteristic of the system that identifies interchanges? We already have mile markers for that.

Numbering the exits by milepost (or, to maintain generality, distance-based reference post) improves relatability between exit numbers and mileposts.  This is a positive benefit.

As to why exit numbers are exclusively mileage-based, part of the reason is message loading.  Back in the late 1960's/early 1970's, when exit numbering in general was still relatively novel, FHWA promoted a dual system where exits would have both sequential numbers (indicated by tabs with the word "Exit") and mileage-based numbers (indicated by tabs with the word "Mile").  The two tabs were stacked on top of each other for each sign, which is a cumbersome arrangement with two added units of message load per sign.  I know from studying old as-builts that Colorado went for this system in the early 1970's, and I believe Roadman has mentioned elsewhere on this forum that it was popular in some of the New England states, but I am not aware it was widely adopted.

As a very broad generalization, the jurisdictions that have been most resistant to distance-based exit numbering or to exit numbering in general have had issues that claw back some of the benefits typically associated with such systems.  California, for example, resisted exit numbering for over 30 years because MUTCD mileposts are not used at all--instead, even Interstates have postmiles that reset by county.  Kansas resisted exit numbering until about 1980, at which approximate time it also converted from a county-based reference post system to MUTCD mileposts on Interstates.  Britain sticks to sequential junction numbering on motorways and has reference posts that are km-based (despite distances on motorway signs being given in miles or fractions thereof) and use small letters and digits in a cryptic format not intended to be deciphered at speed or without training (similar to NYSDOT reference plates).

The northeastern states in the US are actually fairly unusual in blending mileage-based reference posts (for purposes of MUTCD compliance) with sequential exit numbers.  Changing to mileage-based exit numbers unlocks an additional layer of benefit, at least in rural areas.

Quote from: empirestate on February 01, 2018, 08:10:25 AMGood. And why, in their view, does the distance itself have to be the identifying mark, rather than being an additional piece of information?

In the past, a variety of state DOTs have tried confirmation and interchange sequence signs that include exit numbers as well as the cross streets/destinations at the next few exits and the mileages to each.  There are a few scattered examples still standing around the country.  The main issue is message loading--including exit numbers adds at least one unit per line.
"It is necessary to spend a hundred lire now to save a thousand lire later."--Piero Puricelli, explaining the need for a first-class road system to Benito Mussolini

empirestate

Quote from: webny99 on February 01, 2018, 08:35:11 AM
Quote from: empirestate on February 01, 2018, 08:10:25 AM
And why, in their view, does the distance itself have to be the identifying mark, rather than being an additional piece of information?

Because, as I said upthread, using a distance-based system gives the motorist the most possible information in the most non-intrusive way possible.

But, as I added less far upthread, that's not so–using a naming system and a distance-based system gives even more information.

QuoteIt seems you're assuming that identification is the only purpose to a numbering system, which is far from the case.

No, but that's the specific problem before us: how to identify interchanges. Naming them does that more uniquely than numbering them.

Quote
QuoteWhy not identify it using its name, and give its location by indicating which milepost it's at?

Because, how is the average joe-bloe traveler going to know what milepost their exit is at? They aren't, and as such, they won't be able to figure out as specifically how far away it is.

Why aren't they? The milepost can be shown on signs and maps, just as exit numbers are. So they would know what milepost their exit is at by the same method they currently know what number it has.

Quote
Also, if the most information is the best choice, why leave some out? Why not say "The Circleville Interchange, which is at milepost 226" rather than "Exit 226, which is at milepost 226"? It seems that the first way gives the most information, not the second, and thus is actually "the way forward".

Because again, the motorist will have no way of knowing the milepost of a given interchange. If you happen to already know that, then that's all well and fine, but long-distance or out-of-state travelers are highly unlikely to learn/memorize all that.[/quote]

Again; why can't they know the milepost?

QuoteAt least in my opinion, naming would add another level of confusion; as it is certainly information, I fail to see where it is information that will actually help the motorist in reaching their destination, calculating remaining distances, etc. And, as it's not strictly necessary information, it might be on the border of information overload for the average motorist.

But the problem to be solved isn't calculating remaining distances, etc.–it's unambiguously identifying the interchanges. So, you would need to show how mileage-based numbering is better at identifying an interchange and distinguishing it from other interchanges.

Quote from: J N Winkler on February 01, 2018, 10:23:07 AM
Numbering the exits by milepost (or, to maintain generality, distance-based reference post) improves relatability between exit numbers and mileposts.  This is a positive benefit.

But what if the exits don't have numbers? Then there's no need to relate anything–the exit's milepost is its milepost, one and the same.

QuoteAs to why exit numbers are exclusively mileage-based, part of the reason is message loading.  Back in the late 1960's/early 1970's, when exit numbering in general was still relatively novel, FHWA promoted a dual system where exits would have both sequential numbers (indicated by tabs with the word "Exit") and mileage-based numbers (indicated by tabs with the word "Mile").  The two tabs were stacked on top of each other for each sign, which is a cumbersome arrangement with two added units of message load per sign.  I know from studying old as-builts that Colorado went for this system in the early 1970's, and I believe Roadman has mentioned elsewhere on this forum that it was popular in some of the New England states, but I am not aware it was widely adopted.

OK. Using names would eliminate the dual-line numbering problem there; you'd know the interchange's name, and what mile it's at. It's still more information, but it's not two piece of information as likely to be confused with each other. It would be easier for the motorist to select the bit he needs–does he need to know which interchange it is? Use the name. Does he need to know how far away it is? Use its mile.

QuoteThe northeastern states in the US are actually fairly unusual in blending mileage-based reference posts (for purposes of MUTCD compliance) with sequential exit numbers.  Changing to mileage-based exit numbers unlocks an additional layer of benefit, at least in rural areas.

Agreed. So, now we come to the question of whether that additional layer of benefit is worth the cost of implementing the change. I haven't yet been persuaded that it is.

Quote
Quote from: empirestate on February 01, 2018, 08:10:25 AMGood. And why, in their view, does the distance itself have to be the identifying mark, rather than being an additional piece of information?

In the past, a variety of state DOTs have tried confirmation and interchange sequence signs that include exit numbers as well as the cross streets/destinations at the next few exits and the mileages to each.  There are a few scattered examples still standing around the country.  The main issue is message loading--including exit numbers adds at least one unit per line.

OK; so, if the mere fact of being an additional piece of information is undesirable, then that suggests that adding names to numbers isn't the answer. That bring us back to the status quo in New York, which is numbers only, and for the most part sequential ones. And since the benefit of mileage-based numbering doesn't offset the implementation of it, then it seems that the best choice is the "no-build" option–keep things as they are. We can use existing destination legends and intersecting routes as the way to identify the interchanges, and ordinary navigation skills along with typical maps for estimating distances. (Or, you know...just Google it.)

So that's pretty much where my mind ends up on this; it's okay as is. Any other considerations I may have missed?

webny99

Quote from: empirestate on February 01, 2018, 11:32:45 AM
Quote from: webny99 on February 01, 2018, 08:35:11 AM
As I said upthread, using a distance-based system gives the motorist the most possible information in the most non-intrusive way possible.
But, as I added less far upthread, that's not so–using a naming system and a distance-based system gives even more information.
You must have missed it, but I said "non-intrusive" :-D Motorists don't need to know the name of an interchange; they do need to know where it's located. It's the relevance, and extrapolate-ability (homemade word), of the information that matters, much more so than the sheer volume of information.

Quote
QuoteIt seems you're assuming that identification is the only purpose to a numbering system, which is far from the case.
No, but that's the specific problem before us: how to identify interchanges. Naming them does that more uniquely than numbering them.
The problem is how to identify interchanges,in the way most helpful to motorists. With that said, it doesn't matter how unique the identification is, it matters how easy it is to relate that identification to other important information, such as what turn they need to take, how far away it is, etc. "Circleville Interchange" tells me nothing about the location of the interchange, and location is indeed the aspect that the motorist needs to know most about.

QuoteThe milepost can be shown on signs and maps, just as exit numbers are.
That presents some practical challenges. Do you think every map maker on the planet would jump on board immediately?
Most maps already have enough, if not too much, information packed in a small area . :pan:

Quote
But the problem to be solved isn't calculating remaining distances, etc.–it's unambiguously identifying the interchanges. So, you would need to show how mileage-based numbering is better at identifying an interchange and distinguishing it from other interchanges.
Mileage-based isn't necessarily better when it comes to distinguishing. But I think you're overstating the importance of that aspect. Anyone who can tell the difference between "circleville" and "jane byrne" can also tell the difference between "101" and "110". That's somewhat irrelevant here; as in many cases, the problem is calculating remaining distances, etc. It doesn't matter if it takes the motorist 2 seconds or 5 seconds to distinguish between interchanges, it matters how they can use, extrapolate, and act upon, that information.

Quote
So that's pretty much where my mind ends up on this; it's okay as is. Any other considerations I may have missed?
I'm not one to comment on whether it's worth the investment - maybe it isn't, strictly speaking. But considering that a change will someday be implemented, it's still clear that the change should be to mileage-based, as that's the system that, as I've been saying, conveys the most in the most concise manner possible.

J N Winkler

Quote from: empirestate on February 01, 2018, 11:32:45 AMBut what if the exits don't have numbers? Then there's no need to relate anything–the exit's milepost is its milepost, one and the same.

Mileage-based exits still need to be explicitly signed for map relatability, since the vast majority of maps show exit numbers but not mileposts, and mileposts are often hard to find even in online mapping services that offer driver's-eye photography of the physical roadway (like StreetView).

Quote from: empirestate on February 01, 2018, 11:32:45 AMOK. Using names would eliminate the dual-line numbering problem there; you'd know the interchange's name, and what mile it's at. It's still more information, but it's not two piece of information as likely to be confused with each other. It would be easier for the motorist to select the bit he needs–does he need to know which interchange it is? Use the name. Does he need to know how far away it is? Use its mile.

Ultimately you start running into KISS issues.  Let's say I want to find the NY 365/Thruway interchange and that it has been named "Verona" (rather than the arguably equally apt "Rome West") for simplicity.  "Verona" as an interchange name is a lot harder to show on a single-sheet map of New York State than a simple exit number (33 in this case).  And "Verona" + "252," or even "33" + "252," is harder to show (this is after StreetView search for the relevant milepost, BTW--there are many Thruway users who will not even realize that the Thruway has an exit number/milepost cross-reference).  And "Verona" and "33" are themselves layers removed from "252," which corresponds to what a driver would see both on the map and in the field if mileage-based exit numbering is used.  The less cross-referencing is necessary, the less memorization or looking-up the driver needs to do (and of course some drivers will inevitably try to look things up on their phones while behind the wheel), and the more intuitive the guide signing is.

Quote from: empirestate on February 01, 2018, 11:32:45 AMAgreed. So, now we come to the question of whether that additional layer of benefit is worth the cost of implementing the change. I haven't yet been persuaded that it is.

In terms of direct cost of signing, the added cost of going to mileage-based exits is essentially nil because Thruway exits are already signed by number; only the numbers would change.  (I am ignoring for the moment the whole debate about whether milepointing should be revised to match Interstate route designations rather than administrative control.  I agree that any change to existing milepointing would entail significant costs.)  And frankly, the Thruway needs pretty much all of its signs replaced as a result of botched conversions to Clearview and high-performance sheetings--when I drove the Thruway last summer for the first time in 20 years, much of it was at night and on many signs the border was the only element that could be easily recognized.

The main indirect cost of any exit number conversion falls on road-dependent businesses (motels, truck stops, etc.) that advertise themselves by exit number rather than informal interchange name (e.g., "Exit 33" rather than "Verona Exit" or similar).  This is less of an issue with the Thruway because, as a traditional public-authority turnpike rather than a free Interstate, it has less road-oriented adjacent development, since there are fewer exits to begin with.  Moreover, exits are grouped around towns and crossing state highways in a way that allows businesses to advertise their locations by crossroad/city rather than exit number.  (Because free Interstates are more porous in terms of access points, it is often easier for businesses to advertise by mileage-based exit number rather than a highly forgettable county or local road name.)

What would be a showstopper in the case of Arizona I-19, for example, where the effect on roadside businesses is an obstacle to converting from kilometer-based to mile-based exits, would be at most a short-lived inconvenience on the Thruway.

I don't really have a dog in this fight.  The New York transportation authorities will either reach this decision on their own, or be forced into it by FHWA.  I would just observe that while I am aware of many instances of sequential-to-distance-based conversion, I am not aware of any examples of distance-based-to-sequential conversion even in cases where distance-based exit numbers have had to be revised to eliminate differently located zero points (e.g., I-15 in Utah about ten years ago).
"It is necessary to spend a hundred lire now to save a thousand lire later."--Piero Puricelli, explaining the need for a first-class road system to Benito Mussolini



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