Looking at old maps and pictures, I've noticed that there seem to have been a lot more states (and provinces for that matter) using sequential exit numbering systems.
States and Agencies using sequential numbers currently:
New Jersey Turnpike
New York
Connecticut
Rhode Island
Massachuestts
Vermont
New Hampshire
Maine (except Maine Turnpike)
States and Agencies formerly using sequential exit numbers (that I know of):
Ohio Turnpike
Indiana Toll Road
Florida
Georgia
Pennsylvania (which apparently went from mile-based to sequential to mile-based)
I've seen pictures of Iowa, Mississippi, and Colorado with them, and I had a map (which I can't find currently) of either North or South Dakota with them on one interstate. I also have an Indiana map from the mid-1970s that seems to infer that the Kentucky Parkway System (and Kentucky Turnpike) had them as well.
Did other states use them as well?
Don't forget Delaware. And all of Maine is now mile-based (it used to all be sequential).
I think that is changing...if i recfall rightly, i think the Feds are putting heat oin the States to adopt mileage exit numberings....NY i heard is going to start that fairly soon....Connecticut might be a bit more difficult given how tightly packed the exits are, esp on I-95....and it will confuse a lot of drivers to change
I love mileage based exit numbering. Much easier to determine distances along freeways :spin:
unfortunately, the majority of Europe uses sequential X-(
Quote from: Chris on October 26, 2009, 05:33:00 PM
unfortunately, the majority of Europe uses sequential X-(
Austria doesn't, and idk about Switzerland
Quote from: Brandon on October 26, 2009, 05:12:47 PM
States and Agencies formerly using sequential exit numbers (that I know of):
Pennsylvania (which apparently went from mile-based to sequential to mile-based)
I grew up in Pennsylvania and as far back as I can remember (early 1970s) Pennsylvania used sequential exit numbers when it used exit numbers at all until the recent conversion.
I'm not saying it was never was mileage-based in the deep dark past but I need some evidence to support you assertion.
Quote from: Brandon on October 26, 2009, 05:12:47 PM
I also have an Indiana map from the mid-1970s that seems to infer that the Kentucky Parkway System (and Kentucky Turnpike) had them as well.
Did other states use them as well?
From my old Rand-McNally Atlases is does look like the Kentucky Turnpike and, perhaps, the rest of the Parkway system used sequential numbering.
Quote from: ctsignguy on October 26, 2009, 05:32:07 PM
I think that is changing...if i recfall rightly, i think the Feds are putting heat oin the States to adopt mileage exit numberings....NY i heard is going to start that fairly soon....Connecticut might be a bit more difficult given how tightly packed the exits are, esp on I-95....and it will confuse a lot of drivers to change
Hm. This means that my regular exit off the New York State Thruway (Exit 48A) would become Exit 401, or something like that (I don't have the exact mile marker).
Cool.
IMHO milepost numbering is more sensible than sequential numbering in soooo many ways
QuoteHm. This means that my regular exit off the New York State Thruway (Exit 48A) would become Exit 401, or something like that (I don't have the exact mile marker).
A few years ago when FL changed to milepost numbering my regular exits changed from 12 & 13 to 56 & 70.
I remember years ago when AL added metric to all their milepost and exits then later took down all the metric markers, brilliant!!! :pan:
Virginia used sequential numbering on all interstates through 1992. The child routes of I-64 (except I-564, which has no exit numbers) still use it, though. I-264's exits are close enough together in Norfolk and Portsmouth to warrant it, and I-464 is pretty short, but I-664 should probably switch to milepost-based numbering.
Quote from: allniter89 on October 26, 2009, 07:40:54 PM
IMHO milepost numbering is more sensible than sequential numbering in soooo many ways
QuoteHm. This means that my regular exit off the New York State Thruway (Exit 48A) would become Exit 401, or something like that (I don't have the exact mile marker).
A few years ago when FL changed to milepost numbering my regular exits changed from 12 & 13 to 56 & 70.
I remember years ago when AL added metric to all their milepost and exits then later took down all the metric markers, brilliant!!! :pan:
Ha. I remember when I was in 5th grade in 1968 and they were forcing us to learn the metric system because it was a sure thing that we were going to change over before the next decade was up. :hmmm:
Quote from: Brandon on October 26, 2009, 05:12:47 PMPennsylvania (which apparently went from mile-based to sequential to mile-based)
Pennsylvania was always sequential. The exception was I-79 which, for some reason, was sequential in the southern part of the state, and then mileage-based north of I-80.
Quote from: ctsignguy on October 26, 2009, 05:32:07 PM
NY i heard is going to start that fairly soon...
There have been rumors flying around for years about New York going milepost. Incidentally, when I was at my college career fair last week, I asked the guy there from NYSDOT about it. He responded that A) that he had no knowledge of any such plans and B) that he seriously doubted it would ever happen considering it would cost millions to change all the signs.
Although, while we're on this topic, allow me to share this (http://www.mediafire.com/?sharekey=57f390e817768752d6baebe61b361f7ce399ead62ffa2966a4648785df63f216).
It's an Excel file I've had in the works for a few years now, demonstrating what the exit numbers on remaining sequential highways would be if they were switched to milepost.
Two debatable points, though, would be:
1) I follow the mileposts of the numbered route rather than the named highway. This, for instance, means that the New Jersey Turnpike has exits 1, 13, 26, 35, and 44... and then, using I-95 mileposts, drops back to exit 6. The assumption being that in doing this you'd swap out the signage pattern so as to treat through traffic for I-95 as through traffic and going to/from the Turnpike south of there as exiting/entering. Why? Because the numbered route is the more important one, and it always bothers me when exit numbers for an interstate have sudden jumps forward/backward due to joining a toll road. You'll notice that in New York I-87 and I-90 receive the same preferential treatment over the Thruway.
2) I tend to number roads which are continuous with each other continuously. The Hutchinson River Parkway is made to continue off of I-678's exit numbers, for instance. Just seems to make sense.
Also, you may note that it's not quite complete. MA-2, MA-3, and MA-24... I've yet to find milepost data for those highways anywhere.
If NY goes milepost, they might have to reverse the numbers on the Thruway.
How about going from NO exit number to milepost (say California and the Illinois Tollway :P )
Quote from: Master son on October 26, 2009, 09:21:50 PM
If NY goes milepost, they might have to reverse the numbers on the Thruway.
Better yet, renumber the mile markers for one consistent set of mile markers/exit number for I-87 and one consistent set for I-90. It really seems unlikely, though. NYS has no money and the Thruway Authority probably has no motivation to make changes on their stretches of these roads.
Mississippi also used sequential based exit numbers on some stretches of its freeway originally, and mileage based on others. Froggie can tell you when the change to all-mileage based numbers occurred...
Georgia uses sequential-based exit numbers on three freeways that I can think of -- Georgia 400, U.S. 80/J.R. Allen Pkwy. and U.S. 78/Stone Mountain Freeway. The Interstates have been mile-based for at least ten years.
Be well,
Bryant
Quote from: Jim on October 26, 2009, 09:56:00 PM
Quote from: Master son on October 26, 2009, 09:21:50 PM
If NY goes milepost, they might have to reverse the numbers on the Thruway.
Better yet, renumber the mile markers for one consistent set of mile markers/exit number for I-87 and one consistent set for I-90. It really seems unlikely, though. NYS has no money and the Thruway Authority probably has no motivation to make changes on their stretches of these roads.
It looks like in Pennsylvania that they did number the Northeast Extension (I-476) and the "minor" turnpikes (PA 60/Future I-376, PA 43, etc.) to fit the exit numbering of the overall route. However, the mainline turnpike follows this from the Ohio line to Valley Forge where I-76 and turnpike mileage coincide. However, I-276 & Future I-95 east of that point continue the numbering from the Ohio line.
Not a big fan of sequential exit markers, really deceives the real difference between exits or the freeway itself.
Quote from: allniter89 on October 26, 2009, 07:40:54 PMI remember years ago when AL added metric to all their milepost and exits then later took down all the metric markers, brilliant!!! :pan:
Alabama?!
...
Wow, that's nearly the last place I'd expect to voluntarily use metric.
Quote from: Chrisunfortunately, the majority of Europe uses sequential
Portugal is decidedly sequential; Spain is a mix-and-match, often on the same numbered route. It's especially bad on the A/AP7, with two zero origins (Cadiz -- neverminding A7 begins at km post 103 in Algeciras; and France) and several resets and overlaps.
[Fixed quoting. -S.]
A-7 and AP-7 are two different roads. In the end situation, you'll have a tolled AP-7 and a toll-free A-7 running next to eachother along the east coast of Spain. AP roads use sequential, A roads use kmposts.
Other countries that use kmposts are Slovakia, Czech Republic and Poland.
Colorado is another state which used to have sequential exit numbering (in the 1970's at least). I am not sure when the changeover occurred, but exit numbering is now mileage-based. On some older button-copy signs the "ghosts" of the old sequential exit numbers are visible.
QuoteMississippi also used sequential based exit numbers on some stretches of its freeway originally, and mileage based on others. Froggie can tell you when the change to all-mileage based numbers occurred...
Sometime in the 1980s.
QuoteGeorgia uses sequential-based exit numbers on three freeways that I can think of -- Georgia 400, U.S. 80/J.R. Allen Pkwy. and U.S. 78/Stone Mountain Freeway. The Interstates have been mile-based for at least ten years.
IIRC, the Georgia Interstate changeover was more recent than that...
Quote from: froggie on October 27, 2009, 08:11:08 AM
QuoteMississippi also used sequential based exit numbers on some stretches of its freeway originally, and mileage based on others. Froggie can tell you when the change to all-mileage based numbers occurred...
Sometime in the 1980s.
QuoteGeorgia uses sequential-based exit numbers on three freeways that I can think of -- Georgia 400, U.S. 80/J.R. Allen Pkwy. and U.S. 78/Stone Mountain Freeway. The Interstates have been mile-based for at least ten years.
IIRC, the Georgia Interstate changeover was more recent than that...
The Georgia changeover occurred in 1999.
Alabama used KM posts on its freeways in 1996. They were turned sideways later and then removed. I saw a remaining KM post on the I-10 Bayway as recently as late last year...
I'd much rather prefer milepost numbering than sequential numbering. I especially love it traveling south or west, since the numbers count down.
Quote from: Master son on October 26, 2009, 09:21:50 PM
If NY goes milepost, they might have to reverse the numbers on the Thruway.
How about going from NO exit number to milepost (say California and the Illinois Tollway :P )
California is (slowly) installing them, but seems to lack the typical interstate mileposts. The ISTHA has standard interstate type mileposts, but is looking into installing some sort of exit numbering system (discussed over in the Tollway Milemarker thread in the Midwest section). They could easily add numbers to the exits.
Quote from: AARoads on October 27, 2009, 08:55:29 AM
Quote from: froggie on October 27, 2009, 08:11:08 AM
QuoteMississippi also used sequential based exit numbers on some stretches of its freeway originally, and mileage based on others. Froggie can tell you when the change to all-mileage based numbers occurred...
Sometime in the 1980s.
QuoteGeorgia uses sequential-based exit numbers on three freeways that I can think of -- Georgia 400, U.S. 80/J.R. Allen Pkwy. and U.S. 78/Stone Mountain Freeway. The Interstates have been mile-based for at least ten years.
IIRC, the Georgia Interstate changeover was more recent than that...
The Georgia changeover occurred in 1999.
Alabama used KM posts on its freeways in 1996. They were turned sideways later and then removed. I saw a remaining KM post on the I-10 Bayway as recently as late last year...
I remember that. The KM posts were done for the Olympics. There are still a few around in Birmingham that I know of.
Quote from: Brandon on October 27, 2009, 11:01:35 AM
Quote from: Master son on October 26, 2009, 09:21:50 PM
If NY goes milepost, they might have to reverse the numbers on the Thruway.
How about going from NO exit number to milepost (say California and the Illinois Tollway :P )
California is (slowly) installing them, but seems to lack the typical interstate mileposts. The ISTHA has standard interstate type mileposts, but is looking into installing some sort of exit numbering system (discussed over in the Tollway Milemarker thread in the Midwest section). They could easily add numbers to the exits.
Yeah, slowly is an understatement. The project to add exit numbers was launched in 2002 and should have been completed by now but because of a lack of funding completion has been delayed until who-knows-when.
Regarding mileposts, California uses "postmiles" which measure the route's length within a county. Since all maintenance records and project documents make use of postmiles, there is very little incentive for Caltrans to spend money installing standard mileposts. Once again, this being Caltrans, there is one exception. Mileposts were installed on the CA-58 Mojave Bypass when it opened for traffic a few years ago and have since been extended west over the Tehachapi mountains almost to Bakersfield and east to Boron.
Here's a StreetView image of a CA-58 milepost...
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=mojave,+ca&sll=29.728887,-95.440378&sspn=0.002148,0.003449&ie=UTF8&hq=&hnear=Mojave,+Kern,+California&ll=35.043714,-118.110825&spn=0.001012,0.001725&z=19&layer=c&cbll=35.04382,-118.110875&panoid=y-EE7dAiMZex20oUzgXAVQ&cbp=12,35.06,,1,11.58 (http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=mojave,+ca&sll=29.728887,-95.440378&sspn=0.002148,0.003449&ie=UTF8&hq=&hnear=Mojave,+Kern,+California&ll=35.043714,-118.110825&spn=0.001012,0.001725&z=19&layer=c&cbll=35.04382,-118.110875&panoid=y-EE7dAiMZex20oUzgXAVQ&cbp=12,35.06,,1,11.58)
Unlike most people in this thread, I like sequential numbering and hate distance-based numbering. I find it too difficult to figure out the distance between exits in my head. The only time I do like distance-based numbering is when I'm going through an entire state heading west or south. It tells me the remaining distance on the road in that state.
Fortunately for me, New York has sequential numbering! :partyhat:
Kentucky did not use exit numbers at all for years, until the mid-1970s or so, except for the KY 418, US 60, US 27/68 and KY 922 exits on I-75 near Lexington, which were sequentially-numbered. In the mid-1970s Kentucky installed mile-based exit signs on the Mountain Parkway and it was during that time that mile-based markers were added to the exit signs for interstates.
Quote from: mightyace on October 26, 2009, 11:47:15 PMIt looks like in Pennsylvania that they did number the Northeast Extension (I-476) and the "minor" turnpikes (PA 60/Future I-376, PA 43, etc.) to fit the exit numbering of the overall route.
PA 43/PA Turnpike 43, 66, and 576 following the numbering conventions of north-south and east-west routes. PA Turnpike 60 is the odd man out because it sits in the middle of PA 60 and PennDOT didn't do mileage-based exit numbers on their US and PA designated expressways.
Quote from: Chris on October 27, 2009, 03:46:21 AM
A-7 and AP-7 are two different roads. In the end situation, you'll have a tolled AP-7 and a toll-free A-7 running next to eachother along the east coast of Spain. AP roads use sequential, A roads use kmposts.
While they are two different roads, both A and AP 7 fall in the situation I described in my last post.
Other noted routes: AP 4 between Cadiz and Seville uses km; AP 6 northwest of Madrid retains the distance-based exits that A 6 uses; A 8 switches from distance to sequential as it becomes a toll, non-AP route as it approaches France and AP 66 follows the same pattern that A 6 uses.
I haven't checked the other routes yet.
Quote from: myosh_tino on October 27, 2009, 01:49:14 PM
Yeah, slowly is an understatement. The project to add exit numbers was launched in 2002 and should have been completed by now but because of a lack of funding completion has been delayed until who-knows-when.
The Sacramento area is full of numbered exits nowadays, with US 50 receiving them east of Route 99 last year, and west of Route 99 in the last few months. The only freeway that is sorely lacking in numbers now is probably Business 80 north of the 99/50 junction...
I think the Bay Area is also finally starting to catch up as well.
Quote from: Michael on October 27, 2009, 02:37:32 PM
Unlike most people in this thread, I like sequential numbering and hate distance-based numbering. I find it too difficult to figure out the distance between exits in my head. The only time I do like distance-based numbering is when I'm going through an entire state heading west or south. It tells me the remaining distance on the road in that state.
Fortunately for me, New York has sequential numbering! :partyhat:
You don't like distance-based exit numbering, because it's difficult to do mileage estimations in your head. So you prefer sequential exit numbering, which gives you absolutely no distance information... :confused: :hmm: :confused:
Quote from: PAHighways on October 27, 2009, 03:34:55 PM
Quote from: mightyace on October 26, 2009, 11:47:15 PMIt looks like in Pennsylvania that they did number the Northeast Extension (I-476) and the "minor" turnpikes (PA 60/Future I-376, PA 43, etc.) to fit the exit numbering of the overall route.
PA 43/PA Turnpike 43, 66, and 576 following the numbering conventions of north-south and east-west routes. PA Turnpike 60 is the odd man out because it sits in the middle of PA 60 and PennDOT didn't do mileage-based exit numbers on their US and PA designated expressways.
Thanks for the clarification.
And, the PA 60 problem will go away soon once it becomes I-376! :pan:
Quote from: roadfro on October 27, 2009, 09:13:12 PM
Quote from: Michael on October 27, 2009, 02:37:32 PM
Unlike most people in this thread, I like sequential numbering and hate distance-based numbering. I find it too difficult to figure out the distance between exits in my head. The only time I do like distance-based numbering is when I'm going through an entire state heading west or south. It tells me the remaining distance on the road in that state.
Fortunately for me, New York has sequential numbering! :partyhat:
You don't like distance-based exit numbering, because it's difficult to do mileage estimations in your head. So you prefer sequential exit numbering, which gives you absolutely no distance information... :confused: :hmm: :confused:
I can do the math in my head and I still like sequential numbering. As for distance, that's what the Atlas is for. And, I have a hard time remembering mileage-based exit numbers so if I have to open up an atlas it is only slightly easier to use the mile markers than add it up.
But, mainly, having grown up in PA, that's what I was used to. I can recite from memory nearly every road that is at each exit on I-80 and the PA Turnpike Mainline and Northeast Extension under the sequential system, but I can't remember what their mileage numbers are.
For example, I know the main Clarion exit on 80 was #9, Clearfield was #19, Milesburg was #23, US 15 was #30, I-180/PA 147 was #31, my parents' house was at exit #36S, the Northeast Extension was exit #42 and Pocono Raceway was at Exit #43. Exit #43 was appropriate for Pocono Raceway as Richard Petty drove the #43 for most of his career. The only one of those that I remember off the top of my head in the new scheme is that my parents' house is at Exit 241A. (Though half the time I want to call it Exit 240!)
Quote from: mightyace on October 27, 2009, 10:36:30 PM
I can do the math in my head and I still like sequential numbering. As for distance, that's what the Atlas is for. And, I have a hard time remembering mileage-based exit numbers so if I have to open up an atlas it is only slightly easier to use the mile markers than add it up.
But, mainly, having grown up in PA, that's what I was used to. I can recite from memory nearly every road that is at each exit on I-80 and the PA Turnpike Mainline and Northeast Extension under the sequential system, but I can't remember what their mileage numbers are.
Of course, that's just personal preference. I would much rather have the distance handy out the window than have to try and glance at the atlas while driving and estimate the distance based on that. Jake is very good at estimating distances from an atlas; I am not! I also find looking for a milepost and subtracting the distances to be a very satisfying way to spend the time on the road while on a long trip.
Regarding the numbers, it can be just as easy to memorize mileage-based exits. Oklahoma has always had them; I-35 exits in OK: Exit 1, US-77 and WinStar Casino, Exit 3: OK-153 for Thackerville, Exit 72: OK-19, Pauls Valley/Maysville, Exit 92: Purcell south, Exit 95: Purcell north, Exit 104: OK-74, Goldsby/Washington, Exit 109: OK-9, Chickasha and Riverwind Casino, Exit 174: OK-51, Stillwater/Hennessey, and so forth. And Exit 127 in KS is where I-35 splits off from the Kansas Turnpike.
Quote from: Scott5114 on October 27, 2009, 10:47:53 PM
Regarding the numbers, it can be just as easy to memorize mileage-based exits. Oklahoma has always had them; I-35 exits in OK: Exit 1, US-77 and WinStar Casino, Exit 3: OK-153 for Thackerville, Exit 72: OK-19, Pauls Valley/Maysville, Exit 92: Purcell south, Exit 95: Purcell north, Exit 104: OK-74, Goldsby/Washington, Exit 109: OK-9, Chickasha and Riverwind Casino, Exit 174: OK-51, Stillwater/Hennessey, and so forth. And Exit 127 in KS is where I-35 splits off from the Kansas Turnpike.
True, I do have a bit of easier time if there's never been a cutover. Of course, I've had 30 plus year to memorize PA's sequential numbers while mileage based there has been around less than 10 IIRC
Having lived in GA for a few years as a co-op student in the 90's, I never got used to the sequential numbering. To get the distance to your exit in a sequential state, you have to know the mile numbers at each exit then do the subtraction.
All I have to know in NC/SC are the exit numbers and I'm there. Plus, you don't have these Exit xxxA exits in the middle because no one thought they'd build an exit there.
I remember in PA one time I saw a sign on the side of the road that said "NO EXIT 7 WE DON'T WANT IT". This was before their conversion to the distance numbering.
I also remember seeing a Holiday Inn sign south of Chambersburg that referenced Exit 80E in Winchester, VA (instead of 313A--US 50E/US 17S/US 522S).
Quote from: PAHighways on October 27, 2009, 03:34:55 PM
PennDOT didn't do mileage-based exit numbers on their US and PA designated expressways.
I'll chalk that up to some PennDOT idiocy. (Or, more likely, cheapness?)
Most of the non-interstate expressways in PA don't seem to have exit numbers, but to not change the ones that do (I'm mostly thinking of PA-28, since it's the example I use the most) while changing the interstate exit numbers is (was) a dumb move. They should track down a dictionary and look up "consistency". Either all your exit numbers should be based on mileage, or not.
Quote from: Mr_Northside on October 28, 2009, 10:25:01 AMMost of the non-interstate expressways in PA don't seem to have exit numbers, but to not change the ones that do (I'm mostly thinking of PA-28, since it's the example I use the most) while changing the interstate exit numbers is (was) a dumb move. They should track down a dictionary and look up "consistency". Either all your exit numbers should be based on mileage, or not.
Putting exit numbers on non-Interstate expressways is something only District 4 and District 11 have done, and doesn't appear to be a mandate from Harrisburg.
Quote from: AlpsROADS on October 26, 2009, 05:22:07 PM
And all of Maine is now mile-based (it used to all be sequential).
Not quite.
All of I-95 (which includes all of the Maine Turnpike) is mile-based.
I-295 is mile-based from exit 11 north. South of there, they were left as is, as exit 10 neatly lines up to milepost 10ish, with 11 right smack after it at MP 11ish. I guess they decided going all alphabet-soup south of MP 8 would be too much public confusion for only marginal benefit. Close enough!
Off the top of my head, for a little perspective on distance: MP 5 is 2/3 of the way from exit 5 to exit 6, MP 6 is within the exit 7 interchange, and MP 8 is N of exit 9.
Interstates 195 & 395 kept their exit numbers:
I-195 only had exits 1 and 2. Exit 2 is at MP 1.55; 1 at <1. Round up; it works out nicely.
I-395 is 5 mi long, ending at exit 6. Exit 1 for I-95 is @~ MP 0. Close enough. Round up. Fudge it a la 295 if necessary.
Quote from: yakra on October 28, 2009, 11:41:28 PM
All of I-95 (which includes all of the Maine Turnpike) is mile-based.
Not quite! I forgot exit 3 stayed the same! A quick look at google maps puts it just a touch south of MP 2. Given the layout of this interchange, IMO it's a good candidate for being part of a 2A/B or 2A/B/C setup.
Quote from: ctsignguy on October 26, 2009, 05:32:07 PM
I think that is changing...if i recfall rightly, i think the Feds are putting heat oin the States to adopt mileage exit numberings....NY i heard is going to start that fairly soon....Connecticut might be a bit more difficult given how tightly packed the exits are, esp on I-95....and it will confuse a lot of drivers to change
CT might also be difficult because it's tough to get them to change anything.... ever... period. :-D
CT might have too many exits for distance based to work well. Like how NYSDOT rejected distance based exits in the 70s because of NYC.
Quote from: wytout on October 31, 2009, 07:40:50 AM
CT might also be difficult because it's tough to get them to change anything.... ever... period. :-D
When i talked to Jeff this past week, he told me that while it makes sense for a lot of States to do mileage=based number sequences, in Connecticut, it would be a nightmare to sort it all out on I-95 from the state line to East Haven, and I-84/91 around Hartford...the only route it would make sense would be for I-395....except it carries the old Turnpike exit numbers and as with I-95, people are loathe to change what they have been comfy with for a half-century...
Afterall, trying to get around downtown Cincinnati with their countless Exit 1s on both I-71 and I-75 can be a nightmare for those NOT familiar with the area, so i can certainly see his viewpoint!!
Quote from: wytout on October 31, 2009, 07:40:50 AM
Quote from: ctsignguy on October 26, 2009, 05:32:07 PM
I think that is changing...if i recfall rightly, i think the Feds are putting heat oin the States to adopt mileage exit numberings....NY i heard is going to start that fairly soon....Connecticut might be a bit more difficult given how tightly packed the exits are, esp on I-95....and it will confuse a lot of drivers to change
CT might also be difficult because it's tough to get them to change anything.... ever... period. :-D
I could agree with that...CT still doesn't like to use operational lanes at expressway interchanges, although that is beginning to chage with several projects, also CT doesn't like to use 2-way laft-turn lanes. Also, with their recent I-84 widening project, they kept a left exit in there! Exit 29 on I-84 WB is still a left! Although they say $$ was the issue. If that was AL, it STILL would've been removed!
Quote from: deanej on October 31, 2009, 11:48:53 AM
CT might have too many exits for distance based to work well. Like how NYSDOT rejected distance based exits in the 70s because of NYC.
Letter suffixes seem to work OK in Cincinnati, and also in Kansas City.
Quote from: hbelkins on October 31, 2009, 08:12:09 PM
Letter suffixes seem to work OK in Cincinnati, and also in Kansas City.
They work fine in NYC, too.
I-95 has exits 1A, 1B, 1C, 2A, 2B, 3, 4A, 4B, 5A, 5B, 6A, 6B, 7A, 7B, 7C, 8A, 8B, and 8C. So what? It's then after that when it switches to sequential and you have exits 9 and 10 practically on top of each other that it seems odd.
As for sorting it out... it's not difficult. Take the mileage and round it off. There's your exit number. Letter suffix in order if necessary. Hell,
Wikipedia can give you the necessary information.
NYSDOT actually launched a project to convert I-95 to fully sequential exit numbering. As far as I know, exits 1A-C got partially converted to 1, 2, and 3, and then the whole thing just stalled out and hasn't changed since. The testing they did in the 70s was just I-95 and I-890 (the latter of which has the same numbers regardless of sequential or distance based numbering, with the exception of exit 4C; even with the addition of NY 890, it remains entirely distance based).
In NY, exit suffixes denote two ramps that are related somehow (typically by going to the same road in the same interchange), though they are also used when exits are added between two existing exits. I can see why NYSDOT would want to avoid having too many suffixes (not that I necessarily agree with it); it is worth noting that NYC has dictated NY politics since time immoral.
Quote from: Michael on October 27, 2009, 02:37:32 PM
Unlike most people in this thread, I like sequential numbering and hate distance-based numbering. I find it too difficult to figure out the distance between exits in my head. The only time I do like distance-based numbering is when I'm going through an entire state heading west or south. It tells me the remaining distance on the road in that state.
Fortunately for me, New York has sequential numbering! :partyhat:
I agree, I like sequential exit numbering as well....most motorists don't notice mileage in my opinion. But, they do expect exit 2 to be before exit 3. I don't understand what is wrong with sequential numbering...it seems like common sense to me.
Quote from: doofy103 on November 01, 2009, 03:20:23 PM
Quote from: Michael on October 27, 2009, 02:37:32 PM
Unlike most people in this thread, I like sequential numbering and hate distance-based numbering. I find it too difficult to figure out the distance between exits in my head. The only time I do like distance-based numbering is when I'm going through an entire state heading west or south. It tells me the remaining distance on the road in that state.
Fortunately for me, New York has sequential numbering! :partyhat:
I agree, I like sequential exit numbering as well....most motorists don't notice mileage in my opinion. But, they do expect exit 2 to be before exit 3. I don't understand what is wrong with sequential numbering...it seems like common sense to me.
Well what's wrong with it is the fact that if you add in an exit between 2 and 3, what do you number it? 2A makes it seem related to exit 2, especially if 2 already has an A and B so it's given C. Thus if you didn't want to deal with this issue, you would end up having to renumber all the exits after it on the freeway, which would be very costly.
And distance-based also has the added benefit of making it easier to determine how far away your exit is. For instance, you are getting off at exit 267, and see that you are at milepost 193. Thus you have about 74 miles left until your exit.
Quote from: doofy103 on November 01, 2009, 03:20:23 PM
I agree, I like sequential exit numbering as well....most motorists don't notice mileage in my opinion. But, they do expect exit 2 to be before exit 3. I don't understand what is wrong with sequential numbering...it seems like common sense to me.
Motorists do expect exit 2 to be before exit 3...unless they're going the other direction :-D
Where sequential exit numbering seems to make less sense is when exits are greatly spaced. It seems like it might be weird to have an exit 10 be twenty miles from exit 11. And then, what do you do when a new exit is added in between? Adding a new interchange is where mileage-based numbering wins out, because you may only have to add letters to existing signs to accommodate a new ramp, whereas sequential numbering may require renumbering a significant stretch of the highway (unless multiple letters are used or interchanges can be numbered/lettered out of sequence).
There are some points where sequential numbering makes a bit more sense. While Nevada uses milepost-based exit numbers, this principle is slightly disregarded in the Reno-Sparks area on I-80. All exits from US 395 (exit 15) east to Vista Blvd (exit 21) do not fall in their actual milepost zone, due to many interchanges being spaced closer than one mile apart. The seven exits in this range are actually numbered sequentially, in an apparent effort to avoid using lettered exits for unrelated interchanges. The result is that exit 21 ends up being about three miles from exit 22 (which is outside the Reno-Sparks urban area).
QuoteI agree, I like sequential exit numbering as well....most motorists don't notice mileage in my opinion.
For commuter-style travel, typically not. But for distance travel, yes they do notice.
If you live in a state with milepost exit numbering, you can be the life of the party for a few brief moments by explaining "the trick" to exit numbers to people that don't know it. "Hey, did you know that you can find out how far away from..."
Girls may or may not think it's pretty nifty. In any event you could formulate some ludicrous pick-up lines from it!
Quote from: doofy103 on November 01, 2009, 03:20:23 PM
I agree, I like sequential exit numbering as well....most motorists don't notice mileage in my opinion. But, they do expect exit 2 to be before exit 3. I don't understand what is wrong with sequential numbering...it seems like common sense to me.
Oh, I notice mileage. If I know the milepost where I am at and the exit number I'll be using to leave the freeway/interstate/expressway, I can do the math in my head and figure out how long it'll take, if I need to stop for gas before my exit, etc.
Quote from: deathtopumpkins on November 01, 2009, 05:12:43 PM
Quote from: doofy103 on November 01, 2009, 03:20:23 PM
Quote from: Michael on October 27, 2009, 02:37:32 PM
Unlike most people in this thread, I like sequential numbering and hate distance-based numbering. I find it too difficult to figure out the distance between exits in my head. The only time I do like distance-based numbering is when I'm going through an entire state heading west or south. It tells me the remaining distance on the road in that state.
Fortunately for me, New York has sequential numbering! :partyhat:
I agree, I like sequential exit numbering as well....most motorists don't notice mileage in my opinion. But, they do expect exit 2 to be before exit 3. I don't understand what is wrong with sequential numbering...it seems like common sense to me.
Well what's wrong with it is the fact that if you add in an exit between 2 and 3, what do you number it? 2A makes it seem related to exit 2, especially if 2 already has an A and B so it's given C. Thus if you didn't want to deal with this issue, you would end up having to renumber all the exits after it on the freeway, which would be very costly.
And distance-based also has the added benefit of making it easier to determine how far away your exit is. For instance, you are getting off at exit 267, and see that you are at milepost 193. Thus you have about 74 miles left until your exit.
In Central New York, we letter related exits "N/S" or "E/W" (cardinal directions, duh!). A suffixed "A", "B", etc. is an exit added after the initial numbering. I'm not sure if the rest of the state does the same.
Quote from: roadfro on November 01, 2009, 06:16:24 PMWhere sequential exit numbering seems to make less sense is when exits are greatly spaced. It seems like it might be weird to have an exit 10 be twenty miles from exit 11. And then, what do you do when a new exit is added in between?
you call the new exit 10a? Personally I think mileage-based exits fall down when distances between exits are bigger (eg France, UK rural motorways and very rural US ones) - I can imagine it being more confusing to have the junctions go 49, 56, 61 or whatever than 7, 8, 9. After all, you've just passed exit 23 - how many exits is it to your one, 38? The nice sign tells you that you are 17 miles from your destination, but you're going to have to read signs for that junction number, rather than glance at them and count upwards so you know it's the right junction. Sequential over big stretches would be frustrating rather than confusing "come on, where's this exit, it must be soon" kind-of-thing.
QuoteAdding a new interchange is where mileage-based numbering wins out, because you may only have to add letters to existing signs to accommodate a new ramp, whereas sequential numbering may require renumbering a significant stretch of the highway (unless multiple letters are used or interchanges can be numbered/lettered out of sequence).
I think you'd find it's the multiple letters (nothing higher than b in the UK - and that only a handful of times - 3 times on motorways and 4 times on A roads). In Glasgow, Scotland, the M74 is being extended to the M8. Which is fine, except it starts at junction 1 and will have three junctions before that. I don't think kmposts are changing (though junction 1 is km 0, so I have no idea what they are doing for them - I'd guess they'd just consider the M74 as slips off the M8 until the current j1) - a mileage/kmage based system would have to renumber the whole road (itself not a bad thing). However what they are going to do is have 1, 1a, 2, 2a (currently 1), 3 (currently 2), 3a (currently 3) and 4 (currently 4) - just 3 renumbered junctions, rather than 13.
Also in Glasgow, the M8 has a few junctions in close succession, but rather than having 24, 24a, 24b, 24c (no idea on actual exit numbers under a mileage-based system) there's no letter suffixes, but unique numbers. You touch on sequential's benefit here, where junctions are close with your Reno example.
There's pluses and minuses with both systems and I'm on the fence over what one is better.
roadfro: I've always been of the mind that it really depends on what type of road - the New Jersey Turnpike really goes well with sequential numbering IMO, for instance, but I think in most instances mile-based is more practical.
Quote from: english si on November 02, 2009, 01:13:33 PMPersonally I think mileage-based exits fall down when distances between exits are bigger (eg France, UK rural motorways and very rural US ones) - I can imagine it being more confusing to have the junctions go 49, 56, 61 or whatever than 7, 8, 9. After all, you've just passed exit 23 - how many exits is it to your one, 38? The nice sign tells you that you are 17 miles from your destination, but you're going to have to read signs for that junction number, rather than glance at them and count upwards so you know it's the right junction. Sequential over big stretches would be frustrating rather than confusing "come on, where's this exit, it must be soon" kind-of-thing.
It is true that with mileage-based systems, you lose the benefit of having an easy-to-remember sequential number which you can count up or down from your entry point. But as a generalization, even in rural stretches with widely spaced interchanges, I would expect the majority of drivers to find it more useful to be able to estimate the
time until they reach their exit, using a system of exit numbering which is easily related to the distance indications on mileposts.
I can't speak for British drivers who have grown up with sequential junction numbering, but as an American growing up with mileage-based numbering, I can say that I never bother to count the exits between my current location and the exit I need to take. Americans tend to assume that wherever a major road (generally a paved road in thinly populated rural areas) crosses the freeway, an exit will be provided. Mileage-based numbering allows them to ignore the particularities of intersecting road development on the intervening length of freeway, which often includes new exits put in on a fairly regular basis to cater for outlet malls and suchlike commercial development. (Britain has much less of this sort of development in general, and very little of it results in new interchanges even on grade-separated all-purpose roads, because the planning system is highly restrictive and leads to land development costs which are up to ten times those encountered in the US.)
Another factor which affects counting is that in Britain sign designers have the option of showing the junction number on an entry slip, while Americans rarely if ever show exit numbers on entry ramps. In Britain you are sometimes told you are entering at Junction 5; in the US you are never told you are entering at Exit 445A.
QuoteQuoteAdding a new interchange is where mileage-based numbering wins out, because you may only have to add letters to existing signs to accommodate a new ramp, whereas sequential numbering may require renumbering a significant stretch of the highway (unless multiple letters are used or interchanges can be numbered/lettered out of sequence).
I think you'd find it's the multiple letters (nothing higher than b in the UK - and that only a handful of times - 3 times on motorways and 4 times on A roads). In Glasgow, Scotland, the M74 is being extended to the M8. Which is fine, except it starts at junction 1 and will have three junctions before that. I don't think kmposts are changing (though junction 1 is km 0, so I have no idea what they are doing for them - I'd guess they'd just consider the M74 as slips off the M8 until the current j1) - a mileage/kmage based system would have to renumber the whole road (itself not a bad thing). However what they are going to do is have 1, 1a, 2, 2a (currently 1), 3 (currently 2), 3a (currently 3) and 4 (currently 4) - just 3 renumbered junctions, rather than 13.
There is not much difference between sequential and distance-based numbering systems from this standpoint. A certain amount of massaging is possible (and indeed routinely done) with both. California has freeways where the exit numbering is based on non-traversable routings between a projected ultimate terminus and the start of the actual length of traffickable road. Before Utah DOT resurveyed I-15 on a consistent baseline and changed exit numbers accordingly a few years ago, differences in length between the projected and actual alignments of I-15 were dealt with by stretching or compressing (as required) the distances between numbered exits in relation to the actual mileages.
Although one of the touted advantages of mileage-based exits is a transparent indication of distance to exit, this is inevitably approximative, as is mileposting in general unless mileage equations are explicitly indicated. Mileage-based exit numbering, when used with mileposts, is generally good enough to let you know within, say, five minutes how far it is to your desired exit, but it is not good enough to check your speedometer. This is why states with mileage-based exit numbering and mileposts still have surveyed speedometer check sections, and also why I confine my own speedometer check exercises to lengths of the Kansas Turnpike which have not been touched since 1956.
QuoteAlso in Glasgow, the M8 has a few junctions in close succession, but rather than having 24, 24a, 24b, 24c (no idea on actual exit numbers under a mileage-based system) there's no letter suffixes, but unique numbers. You touch on sequential's benefit here, where junctions are close with your Reno example.
To be fair, in the absence of explicit mileposting in California (county-based mileposting is still all there is right now), there is little to choose between sequential and distance-based systems in that state. There are urban freeways with closely spaced exits (think downtown LA freeway ring) where sequential numbering inevitably has an advantage. Plus, in the absence of explicit mileposts referred to the same starting point as the exit numbers, and without knowing how long the freeway is in each county through which it passes, it is not possible to know the distance to the desired exit until you pass an intermediate exit. This can take a very long time in the California desert--think I-10 in eastern Riverside County.
QuoteThere's pluses and minuses with both systems and I'm on the fence over what one is better.
I'm mileage-based all the way!
Quote from: Michael on November 02, 2009, 10:05:16 AM
In Central New York, we letter related exits "N/S" or "E/W" (cardinal directions, duh!). A suffixed "A", "B", etc. is an exit added after the initial numbering. I'm not sure if the rest of the state does the same.
I believe the rest of the state uses A/B (except Northern NY and the Southern Tier). Since about a year or two ago, central NY has actually been in error in doing that, ever since the adeoption of the federal MUTCD.
Quote from: deanej on November 02, 2009, 02:42:37 PM
Quote from: Michael on November 02, 2009, 10:05:16 AM
In Central New York, we letter related exits "N/S" or "E/W" (cardinal directions, duh!). A suffixed "A", "B", etc. is an exit added after the initial numbering. I'm not sure if the rest of the state does the same.
I believe the rest of the state uses A/B (except Northern NY and the Southern Tier). Since about a year or two ago, central NY has actually been in error in doing that, ever since the adeoption of the federal MUTCD.
Southern NY is generally directional as well, although there are exceptions. I-95 has exits 18A-B for Mamaroneck Avenue. The Henry Hudson Parkway has 23A-B for Broadway/US 9.
After Maine converted to mileage-based exits, I thought for sure that NH and VT would follow suit. I emailed VTrans and they said (back in 2005) that they had no plans to convert to mile-based exits. Figures... it would be the easiest state to do it in, as not a single interstate exit has been added since the interstate system was constructed, and 95% of the exits are more than 2 miles apart, with some being 10-15 miles apart.
Converting in CT would be confusing to some, since especially on I-95 between New York and New Haven, there are 50 exits in 50 miles, so you may have exits only changed by 1 or so. I would number them so that you wouldn't have A and B exits, whenever possible. If a couple exits are a mile or so off, no big deal. I-84 through Hartford would be more challenging, but that could be solved by closing/consolidating some exits. I-395 would benefit the most as its exits start at "77", though if it was up to me, a mile-based system would continue I-95's exits on I-395, harking back to the turnpike days.
Any changes to the New Jersey Turnpike exits should have the lowest exit at the south end and the highest exit at the GWB, and not convert to I-95 mileage halfway up. The Thruway would be a bit more challenging, but I'd still have Exit 1 be where the Thruway begins, and have I-90 remain "backwards numbered".
It's good to have a UK perspective upon this, as they have an entire freeway network with sequential junctions, and so can provide insight we might not be able to have based on its limited application in the U.S.
Can anyone inform me upon whether the UK uses milemarker/kmarker signs posted along the motorways? This is one of the major niceties that aids mileage-based systems the most. Even if there is no Exit 223, there will still be a marker informing you that you are at Mile 223, and if you're planning on getting off at 243, you still have 20 miles to go, and will be reminded of where you are at one-mile intervals. Missouri even goes through the extra effort of putting markers every fifth of a mile, complete with small reassurance markers, so you will be reminded you are on I-44 East at 72.0, 72.2, 72.4, 72.6, 72.8, as well as at 73.0 (and so on).
I used to reduce my cruise control by three MPH–setting it at exactly 72 MPH–upon entering Missouri, so that I would be at my exit in Springfield in exactly one hour!
Quote from: Scott5114 on November 03, 2009, 10:58:15 PMCan anyone inform me upon whether the UK uses milemarker/kmarker signs posted along the motorways?
Britain (not sure about NI) has km-posting of sorts. The signs in question are called "driver location signs" and are similar in function to the enhanced location reference markers you see on freeways in a number of US cities. But they are not well-formatted for navigational purposes. The standard design (used both on motorways and all-purpose roads) has blue background, yellow (!) legend, and white border, and formats the information like this:
M6
A
193.7
where "M6" is the road number, "A" is a carriageway designator (A = going away from London, B = going towards London, and there are other designators as well, designed e.g. for use with slip roads within interchanges), and "193.7" is the distance in km from a designated datum point which may be, but often is not, the start of the route.
Further information can be found in the Highways Agency's Interim Advice Note on driver location signs:
http://www.standardsforhighways.co.uk/ians/pdfs/ian93.pdf (http://www.standardsforhighways.co.uk/ians/pdfs/ian93.pdf)
Before driver location signs were introduced, motorways and certain important A-roads had flexible roadside posts giving the distance in km and tenths from a given datum point, as well as an arrow pointing to the nearest emergency telephone. But the legend on these posts was much smaller than on the current driver location signs.
Evidence that I am an utter egghead, file #37601:
So, yesterday, when I was bored, I came up with a formula for calculating the relative benefit of switching to milepost numbering on a highway by highway basis.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fimg193.imageshack.us%2Fimg193%2F5333%2Fmilepostbf.png&hash=1d99a94cdcea9c697395f067bd8a3134d4b4e235)
Some calculated values of FB with this formula....
I-84, NY: 7.01
I-84, CT: 3.01
I-84, MA: 0.31
I-87, NY: 169.19
I-90, NY: 739.14
I-90, MA: 22.96
I-91, CT: 1.72
I-91. MA: 1.60
I-91, VT: 18.92
I-95, NY: 0.38 (0.015L=0.35)
I-95, CT: 3.78
I-95, RI: 2.16
I-95, MA: 2.94
I-95, NH: 1.29
The very large values for I-87 and I-90 in New York are, of course, due to the Thruway making the numbers start over and run backwards. Were they sequentially numbered properly FB would be considerably lower.
No highway I've looked at so far in Connecticut or Rhode Island produces a value of FB>5. In Massachusetts, only I-90 and I-495 do (Well, MA-2 probably would as well if I had milepost data for it...). In New Hampshire, only I-93 and NH-101 do. Meanwhile, in Vermont, Both I-89 and I-91 do; and in New York, every primary interstate except for I-95 does.
So there you go. Take all that for whatever subjective worth you wish...
I think I like mileposts for consistency, and suffix letters in densely packed areas are fine by me. Hell, look at Kansas City, with its Exit 2 complex. The numbering (lettering) of the exits is the least of their problems.
Quote from: Duke87 on November 04, 2009, 07:36:07 PM
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fimg193.imageshack.us%2Fimg193%2F5333%2Fmilepostbf.png&hash=1d99a94cdcea9c697395f067bd8a3134d4b4e235)
The [mu] and [m] variables are the same thing, is one of them supposed to be median? :confused:
Quote from: Duke87 on November 04, 2009, 07:36:07 PM
Evidence that I am an utter egghead, file #37601:
So, yesterday, when I was bored, I came up with a formula for calculating the relative benefit of switching to milepost numbering on a highway by highway basis.
[some large image] ....
a real egghead would use LaTeX to write up those formulae!
Quote from: agentsteel53 on November 04, 2009, 09:17:31 PM
Quote from: Duke87 on November 04, 2009, 07:36:07 PM
Evidence that I am an utter egghead, file #37601:
So, yesterday, when I was bored, I came up with a formula for calculating the relative benefit of switching to milepost numbering on a highway by highway basis.
[some large image] ....
a real egghead would use LaTeX to write up those formulae!
An even bigger egghead would then refer to it as L
AT
EX!
Quote from: J N Winkler on November 02, 2009, 02:36:35 PM
To be fair, in the absence of explicit mileposting in California (county-based mileposting is still all there is right now), there is little to choose between sequential and distance-based systems in that state. There are urban freeways with closely spaced exits (think downtown LA freeway ring) where sequential numbering inevitably has an advantage. Plus, in the absence of explicit mileposts referred to the same starting point as the exit numbers, and without knowing how long the freeway is in each county through which it passes, it is not possible to know the distance to the desired exit until you pass an intermediate exit. This can take a very long time in the California desert--think I-10 in eastern Riverside County.
It's true that California doesn't use statewide mileposts. However, according to the Cal-NExUS site, their exit numbers are posted based on statewide mileage. Thus, one *can* generally use exit numbers to estimate mileage on California Freeways. In California's case, estimating distance by exit number is far more convenient than relying on a postmile panel.
Nevada DOT follows a milepost/exit number policy similar to that of Caltrans. This is particularly evident in the case of US 395. All exits on freeway portions of US 395 in Reno and Carson City are based on the statewide mileage, despite the fact that the county mileage is smaller. This is also done on I-80 (although in this case, the interstate uses MUTCD-style mileposts with statewide mileage in addition to the Nevada-style mileposts indicating county mileage at bridges/interchanges).
Quote from: roadfro on November 05, 2009, 01:24:21 AMIt's true that California doesn't use statewide mileposts. However, according to the Cal-NExUS site, their exit numbers are posted based on statewide mileage. Thus, one *can* generally use exit numbers to estimate mileage on California Freeways. In California's case, estimating distance by exit number is far more convenient than relying on a postmile panel.
This is true. The point I was actually trying to make is that in order to orient yourself in relation to the exit you want, you must
first pass a numbered exit. In the desert, where exits are widely spaced (something like 10-20 miles), that can entail a significant amount of driving time.
To give an example, suppose I enter I-10 at Ford Dry Lake Rd. (Exit 217) going west. I won't know how far I am from, say, the I-405 stack interchange until I pass the next exit (Exit 201), 16 miles and about 14 minutes later. In contradistinction, if mileposts were provided in addition to (or instead of) the postmiles, I would know the distance in less than a minute.
add to that that Ford Dry Lake Road is about a half-mile long and leads to Chuckwalla Valley Road, which is the road most people intend to take, but is not labeled on any sign. Yep, I've missed that exit because I had no idea that "exit 219" on the map was that unlabeled exit in the field, which is oh-so-informatively located about 117 miles from the Riverside County line.
And then I had to drive 17 miles east to the next exit (the other end of Chuckwalla Valley Road).
California postmiles - dumb as Hell.
The very first time I drove in California, I crossed the Colorado River on I-10 in December 1998, bound for Los Angeles. My thought process was as follows:
* Why did that exit not have a number?
* Why are there no mileposts?
* What do those little white things at the side of the road mean?
* Why does every little white thing have "RIV" at the top?
Eventually, around RIV-10-110.3, I figured out that these "little white things" were mile markers of some description. Like many people who had never actually visited LA, let alone driven in its basin, I had a sort of mental map where Riverside County ended, umm, about five blocks east of the Pacific Ocean.
* Ah! (RIV-10-100.5) I am about 100 miles from LA.
yeah, I wonder who decided to use county-based postmiles in the 1920s when they were first put up. Other states had mileposts that were zeroed at the state line or route terminus, why not CA? A lot of things CA did were brilliant (red stop signs, etc) but this idea was asinine.
Quote from: agentsteel53 on November 05, 2009, 10:51:06 AM
yeah, I wonder who decided to use county-based postmiles in the 1920s when they were first put up. Other states had mileposts that were zeroed at the state line or route terminus, why not CA? A lot of things CA did were brilliant (red stop signs, etc) but this idea was asinine.
It's not unusual on non-interstates. Illinois uses a county based mileposting system for state and US routes. It's a green cricle with the following inside:
{route number - black on white}
{county - white on green bar}
{mileage - black on white}
Thus:
83
DUPAGE
8
I can't seem to find a photo of one online.
At the time they were originally introduced, California "postmiles" were actually station markers rather than mileposts per se. I suspect, but cannot definitely prove, that a county-based system was adopted for computational convenience. For Mexico-to-Oregon routes like US 101, 99, etc. and other very long multi-county routes, the maximum values that have to be dealt with are much lower in a county-based system than in a statewide system.
To be fair to Caltrans, I don't think it was ever the intention that the postmiles be used for motorist navigation. Caltrans considered the milepointing issue in a major retrospective of guide signing issues in the early 1960's and it is clear that any system introduced for motorist navigation would be distinct from the postmile system (Caltrans considered "paddle" mileposts at this time). My recollection is also that the final report on the exit numbering study in 1972 recommended not just that exit numbers be installed, but also that consideration be given to provision of mileposts in rural areas, milepointed on a statewide rather than county basis to maintain relatability with the exit numbers. But the Caltrans brass spiked that study, probably for cost and presentational reasons. (The copy of it I found in the Caltrans library was stapled to a green-ink letter from a member of the public who was angry that exit numbers, mileposts, etc. were even being considered as opposed to, say, spending the money on new schools.)
Clued-in motorists depend on the postmiles by default because statewide mileposting is just not a service Caltrans provides at present, except (according to Wikipedia) on a pilot basis on certain freeways. But, as Jake and I have both found, the postmiles are unhelpful where they are not outright misleading.
the only value I get out of CA postmile paddles is that they have the letter R if it is a post-1963 realignment, which means that if I am clever, I can find the old alignment nearby. Oh and sometimes they have an older route number - there's a 395 postmile in Escondido, some 7s left on the 710 freeway, and some 11s on the 110.
IMO, JN Winkler is correct in that the white postmiles that are found on California's highways were not meant to be used by the motoring public. Instead, they are reference markers that are used by CalTrans and local governments for maintenance and route logging purposes. I never used postmiles to calculate distances because they are hard to read and are not posted at regular intervals.
Like I said in a previous post, the only highway that has standard green mileposts is Hwy 58 between Bakersfield and Barstow. They first appeared on the Mojave Bypass freeway and have since been extended over the Tehachapi mountains. I'm driving to Las Vegas next week so it'll be interesting to see if the use of mileposts has expanded.
Quote from: Brandon on November 05, 2009, 11:26:21 AM
It's not unusual on non-interstates. Illinois uses a county based mileposting system for state and US routes. It's a green cricle with the following inside:
{route number - black on white}
{county - white on green bar}
{mileage - black on white}
Thus:
83
DUPAGE
8
I can't seem to find a photo of one online.
I have a few of them on millenniumhwy.net
Quote from: hbelkins on November 05, 2009, 03:41:46 PM
I have a few of them on millenniumhwy.net
Thanks, HB, just found this one, third photo down on the page. :cool:
http://www.millenniumhwy.net/signs%26sights/il/gallatin/index.html (http://www.millenniumhwy.net/signs%26sights/il/gallatin/index.html)
Quote from: mightyace on November 04, 2009, 07:48:46 PM
The [mu] and [m] variables are the same thing, is one of them supposed to be median? :confused:
Whoops, documentation error. Yeah, µ is the mean, m is the median.
I have another example of the mileposts used on non-Interstate Illinois highways:
(https://www.aaroads.com/midwest/illinois006/us-006_wb_app_27th_st_02.jpg) (https://www.aaroads.com/midwest/illinois006/us-006_wb_app_27th_st_02.jpg)
Ontario used to post sequential exit numbers until May 1, 1982 when they were changed over to our current system which is posting them by the nearest km post according to thekingshighway.ca
I thought they used sequential, switched to mile-based, and then switched to km-based shortly thereafter?
Quote from: deanej on January 07, 2010, 10:35:03 AM
I thought they used sequential, switched to mile-based, and then switched to km-based shortly thereafter?
IIRC, that's what Quebec did.
And to think I remeber reading somewhere that that's how 401's numbers went. Can't find it now, though.