I would like to know, could anyone tell me of any highways using unusual milepost schemes? Such highways could include mileposts increasing backwards (north to south or east to west, rather than south to north or west to east), or some other weird scheme.
I know that SR 85 in Arizona has an unusual milepost scheme, with the zero point at Gila Bend where mileposts increase going both north and south from there.
Texas SH 130 sees mileposts in the 400s east of Austin.
Also, on PR-22 in Puerto Rico, the kilometer posts increase east to west. I presume the reason for this is for DTOP won't have to re-post everything if the extension to Aguadilla is ever built.
Quote from: Pink Jazz on October 20, 2014, 09:33:28 PM
I would like to know, could anyone tell me of any highways using unusual milepost schemes? Such highways could include mileposts increasing backwards (north to south or east to west, rather than south to north or west to east), or some other weird scheme.
I know that SR 85 in Arizona has an unusual milepost scheme, with the zero point at Gila Bend where mileposts increase going both north and south from there.
I-795 in North Carolina. Starts at 0 on the north end and increases as you go south.
Alaska is full of milepost weirdness. Many highways have mile zeros on other highways, most notably the Alaska Highway (part of AK 2) whose mile zero is in northern British Columbia, and the highest conventional milemarker is 1421 (plus an elaborate mile 1422 monument at highway's end in Delta Junction). The Parks Highway (AK 3) starts in Palmer AK, but its mile zero is about 35 miles south in downtown Anchorage.
AK 1's mile zero is at the south end of AK 9 in Seward. That applies to both the Seward Highway segment east of Tern Lake Junction, and the Sterling Highway segment west of Tern Lake (Alaska mileposts are keyed to named rather than numbered highways). So travelers on AK 1 see mileposts descending to around 38 as they approach the junction (whether coming on the Sterling Highway from Homer, or the Seward Highway from Anchorage), then the mileposts start increasing again on the other side of the junction.
Keying mileposts to named rather than numbered highways also results in numbered highway mileposts resetting as they switch from one named highway to another. For example, AK 2 is milemarked east to west on its Alaska Highway segment, then the mileposts reset in Delta Junction as AK 2 switches to the Richardson Highway, then they reset again in Fairbanks when AK 2 switches to the Steese Highway, with Steese mileposting continuing in Fox on both AK 2's continuation on the Elliott Highway and AK 6's continuation of the Steese Highway.
The milemarkers on the Richardson Highway (all of AK 4 plus part of AK 2) start at its old south end at the old Valdez townsite, four miles east of the highway's current south end. When Valdez was moved after it got trashed in a 1964 tsunami, the highway was extended, but there are no mileposts on the extension and all the other mileposts were left as is. Since people use mileposts as street addresses, Alaska DOT&PF is especially reluctant to recalibrate mileposts.
IIRC, US 75 in Texas has numbers that start at 200 at the Red River and increase going southward.
I seem to recall reading somewhere that all non-Interstate mile markers in Texas are unconventional in some way, I just don't quite remember the method.
Arizona usually keeps mileposts going on branches, with some rather odd results (most obviously I-17). The 77/79 and 77/177 splits show the general idea well. And SR 85 north of Gila Bend is numbered as former US 80 (unless it's changed recently).
http://www.azdot.gov/docs/business/state-milepost-map.pdf
Texas does the weird thing on all non-Interstates. Someone else can explain it.
Quote from: hbelkins on October 20, 2014, 09:53:31 PM
I-795 in North Carolina. Starts at 0 on the north end and increases as you go south.
That's not unusual. Spur Interstates are supposed to start at the parent.
A portion of VA-294, the Prince William Parkway, has kilometre posts running from east to west. The markers are also erroneous because they incorrectly abbreviate it as "KM" instead of the proper "km."
Canned explanation of Texas non-Interstate milepointing:
* The basis of the Texas uniform reference marker system is two lines. One is east-west and parallels the top edge of the Texas Panhandle ten miles to the north, while the other is north-south and passes through a point ten miles due west of the far western tip of the state near El Paso.
* Each segment of state highway has an origin point whose value is equal to that point's distance in miles from the east-west line (if the route runs north-south) or from the north-south line (if the route runs east-west). All reference markers on the state highway segment count up from this origin point according to miles along the route centerline. East-west routes count up going east and north-south routes count up going south.
Routes like SH 130 that have mileposts as their reference markers are actually fairly rare, and this usually occurs in coordination with exit numbering. The typical reference marker on a Texas state highway is three digits (white on green, Series D, zero fills used as necessary) mounted just below a route marker on the same post.
The ten-mile offset built into the reference marker system ensures that only Interstates can have mileposts below 10 in Texas.
In NJ (Both East to West):
I-76
AC Expressway
Quote from: J N Winkler on October 20, 2014, 10:44:10 PM
Canned explanation of Texas non-Interstate milepointing:
One thing I haven't been able to determine: do these reset at county lines?
Also, it would be possible to have a number less than 10 if a route is extended west or south from its original endpoint, and the extension is rather indirect. Unless they always renumber after extending.
Quote from: NE2 on October 20, 2014, 11:02:57 PM
One thing I haven't been able to determine: do these reset at county lines?
Nope, Texas mileposts are continuous across county lines. Typically you get a reassurance marker along with the milepost every 2 centerline miles.
In Texas, US 75's exit numbering starts with 1A (the exit to Woodall Rodgers/Spur 366) and climbs to 75 (the welcome center just over the river from Oklahoma). I've never paid attention to the markers.
Quote from: NE2 on October 20, 2014, 11:02:57 PMOne thing I haven't been able to determine: do these reset at county lines?
As Lordsutch says--No. The numbering is supposed to be continuous and statewide. However, TxDOT's documentation is unclear on whether a given route can have multiple origin points. I suspect this is the case because it offers a convenient way of handling milepointing for routes that exist in multiple pieces in Texas (e.g. US 54, US 62, US 180), but it does create at least a theoretical possibility that a route of sufficiently circuitous alignment could have duplicate markers measured from different origin points.
QuoteAlso, it would be possible to have a number less than 10 if a route is extended west or south from its original endpoint, and the extension is rather indirect. Unless they always renumber after extending.
This is a nitpick, but in the case of north-south routes, the situation you describe would need a northward extension to arise.
I don't know how TxDOT handles such awkward extensions in its scheme. I do know, however, that reference marker values less than 10 are explicitly forbidden. In principle they could handle an extension by defining a new origin point specifically for it, but this could easily result in duplicate marker values and I don't know how those are handled. For that matter, I don't know how they deal with alignment changes that affect mile progression. The documentation just talks about programming in new reference markers, but says nothing about ahead/back mile equations (a very common technique for other state DOTs) or postmile prefixes (the Caltrans solution).
It has been reported in MTR that zero reference markers exist and can be found deep in the interior of Texas. This is clearly impossible with the current system. However, the former system was based on control sections (milepointing reset at each control section terminus), and the current one was devised in 1990 by remapping the control-section mileposts then existing for each route onto the route length across the entire state. Since I don't think route-based control sections straddle county lines, presumably it would have been normal to see zero markers at county lines. Stragglers that somehow survived in the field after the 1990 conversion may have been the basis of the MTR report.
Interstate 19 has its markers in kilometers
Quote from: KG909 on October 21, 2014, 12:21:50 AM
Interstate 19 has its markers in kilometers
It has mileposts installed as well.
Doesn't Delaware SR 1 use km based exits? I believe it uses standard mile posts though. I guess that can be considered unusual.
Quote from: SignGeek101 on October 21, 2014, 12:28:45 AM
Quote from: KG909 on October 21, 2014, 12:21:50 AM
Interstate 19 has its markers in kilometers
It has mileposts installed as well.
Doesn't Delaware SR 1 use km based exits? I believe it uses standard mile posts though. I guess that can be considered unusual.
Oh I haven't been on it since like 2007, before mileposts. Also I'm not sure about Delaware route 1, I still don't know that much about other roads.
Quote from: KG909 on October 21, 2014, 12:38:40 AM
Quote from: SignGeek101 on October 21, 2014, 12:28:45 AM
Quote from: KG909 on October 21, 2014, 12:21:50 AM
Interstate 19 has its markers in kilometers
It has mileposts installed as well.
Doesn't Delaware SR 1 use km based exits? I believe it uses standard mile posts though. I guess that can be considered unusual.
Oh I haven't been on it since like 2007, before mileposts. Also I'm not sure about Delaware route 1, I still don't know that much about other roads.
Yes, exit numbers along the SR 1 Turnpike are in kilometers. Nothing else remains metric along the turnpike, though it was fully signed with those units when the Dover to Smyrna portion opened to traffic in December 1993.
The mileposts and exit numbers on the I-90 part of the NY State Thruway increase to the west instead of to the east, due to their continuing from the I-87 part that starts in Yonkers, north of NYC.
When the earlier portions of DE 1 first opened, the exit numbers were originally mile-marker based but then changed to kM-based exit numbers shortly thereafter. IIRC, the highest exit number (near or at I-95) used to be just over 100; then it jumped to the 160s.
What is the rationale for Texas banning mileage below 10 on non-interstates?
Quote from: Henry on October 21, 2014, 12:13:08 PM
The mileposts and exit numbers on the I-90 part of the NY State Thruway increase to the west instead of to the east, due to their continuing from the I-87 part that starts in Yonkers, north of NYC.
Technically that's just the Thruway mileage, so another example of mileposts following a named road rather than the interstate number. They're all over.
More interesting: the Garden State Parkway's mileposts in NY are backwards because it's considered part of the Thruway.
Quote from: NE2 on October 20, 2014, 11:02:57 PM
Quote from: J N Winkler on October 20, 2014, 10:44:10 PM
Canned explanation of Texas non-Interstate milepointing:
One thing I haven't been able to determine: do these reset at county lines?
In the direction of increasing numbers (east or south) the next even number will be posted at a county line, regardless of the distance from the previous marker. They make exceptions when the normal placement of a marker is close to the county line (I've seen them a few hundred feet off, but don't know what the limit is). These county line reference markers are on the right side of the road when viewed traveling in the direction of increasing numbers. From there, they alternate between left and right, except on some divided roads that have markers on both sides every two miles. This means that sometimes there are two consecutive markers on the south or west side of the road, and that the numbers add up faster than mileage does. I can't find the procedure for placing markers on county lines in the manual, but they clearly do. You can see marker placement on this map http://www.txdot.gov/apps/statewide_mapping/StatewidePlanningMap.html (http://www.txdot.gov/apps/statewide_mapping/StatewidePlanningMap.html)
QuoteAlso, it would be possible to have a number less than 10 if a route is extended west or south from its original endpoint, and the extension is rather indirect. Unless they always renumber after extending.
If you open the map and see the first marker on US 83, it's 10 on the Oklahoma state line. In order for the number to be below 10, the highway would have to be "extended" into Oklahoma. In the west, the map shows a mile 10 on Loop 375 east of the state line. I don't know what they'd do if that highway were extended westward. One of the rules is that markers are generally not to be moved, even if route changes make their numbers inaccurate in terms of mileage. They're "reference markers," not "mile markers" (they're routinely inaccurate across county lines, anyway). Having read the manual, my guess is that they'd either make an exception and change the 10 to 10A and move it to the west end and have a more than two mile gap between 10A and 12, or they'd move mile 10 to the new west end and change the existing 10 to 11 (odd numbers are used to fill gaps in some situations).
A useful map showing how the strange grid system works is here http://onlinemanuals.txdot.gov/txdotmanuals/trm/reference_markers_coordinates.htm (http://onlinemanuals.txdot.gov/txdotmanuals/trm/reference_markers_coordinates.htm)
This all leads to the question of "why?". I have no idea where the idea for the grid system comes from, but the ritualistic placement seems to be based on a wish never to move the markers after they're placed (presumably for purposes of consistency in identifying any particular point on a road). That intent is evident multiple times, such as when two routes are combined and the markers along the cancelled designation are left in place regardless of inaccurate mileage and renumbered according to the new designation. http://onlinemanuals.txdot.gov/txdotmanuals/trm/reference_marker_installation_procedures.htm#i1009720 (http://onlinemanuals.txdot.gov/txdotmanuals/trm/reference_marker_installation_procedures.htm#i1009720)
Quote from: vdeane on October 21, 2014, 01:01:16 PMWhat is the rationale for Texas banning mileage below 10 on non-interstates?
The documentation doesn't explain, but since reference marker values are posted vertically with zero fills, I suspect the motivation is to build in a reality check in the event someone reads a reference marker from bottom to top instead of top to bottom. If marker values in the zero-to-ten range were permitted, you could have marker values in the northwestern corner of the Panhandle where "002" was intended (which is plausible for a north-south route) but "200" was read instead (which is plausible for an east-west route).
Bit of trivia: in its documentation, TxDOT uses US 82 across Texas as an example of the reference marker system in operation. Lowest marker value is 220 at the Yoakum County line (western edge of the Texas Panhandle) and highest marker value is 798 in Texarkana. This is a difference of 578 miles. However, Google Maps gives the length of US 82 across Texas as 565 miles. Where did the extra 13 miles go?
(Edit--Wxfree's post, which came through as I was composing this one, offers a possible explanation for the 13-mile discrepancy.)
Quote from: wxfree on October 21, 2014, 01:19:27 PMQuoteAlso, it would be possible to have a number less than 10 if a route is extended west or south from its original endpoint, and the extension is rather indirect. Unless they always renumber after extending.
If you open the map and see the first marker on US 83, it's 10 on the Oklahoma state line. In order for the number to be below 10, the highway would have to be "extended" into Oklahoma.
The difficulty NE2 describes would never arise in the case of a route that starts at the state line. Rather, it would arise in the case of a route that starts X distance from the state line at a point where the latter is fairly near one of the axes of the marker system--say, the western tip near El Paso, or the northern edge of the Panhandle. If the length of the extension is greater than X, then you have a situation where a marker value less than 10 (which is not permissible) must be used if marker values on the extension are generated by counting back from the origin point.
It is quite easy to produce an extension with this characteristic. All you have to do is to follow a circuitous path back to the state line, e.g. by winding back and forth across multiple switchbacks, or going straight back to within a mile or two of the state line and then turning at a right angle to follow it for an extended distance.
QuoteThis all leads to the question of "why?". I have no idea where the idea for the grid system comes from, but the ritualistic placement seems to be based on a wish never to move the markers after they're placed (presumably for purposes of consistency in identifying any particular point on a road). That intent is evident multiple times, such as when two routes are combined and the markers along the cancelled designation are left in place regardless of inaccurate mileage and renumbered according to the new designation. http://onlinemanuals.txdot.gov/txdotmanuals/trm/reference_marker_installation_procedures.htm#i1009720 (http://onlinemanuals.txdot.gov/txdotmanuals/trm/reference_marker_installation_procedures.htm#i1009720)
Yes, the purpose of the marker system is to allow feature descriptions and highway performance data (such as crash reports) to be bound to a route, marker value, and offset from marker. Where a route is renumbered but no alignment change (due to relocation, etc.) is involved, it is convenient for the only transformation applied to a marker to be change of the route and marker value (i.e., no translation along route centerline), as this allows feature and performance data pre-dating the renumbering to be directly compared to that following the renumbering.
Relocations typically involve not just changes in alignment but also upgrades to features that affect the safety performance of the road, so before/after performance data cannot be compared on the same basis. In such cases there is provision for resurveying the markers and communicating their new locations to TxDOT TPP for inclusion on the statewide marker map.
Quote from: PHLBOS on October 21, 2014, 12:22:34 PM
When the earlier portions of DE 1 first opened, the exit numbers were originally mile-marker based but then changed to kM-based exit numbers shortly thereafter. IIRC, the highest exit number (near or at I-95) used to be just over 100; then it jumped to the 160s.
Hm. I didn't know that. But why would they change it to kilometers?
Quote from: adventurernumber1 on October 21, 2014, 04:01:41 PM
Quote from: PHLBOS on October 21, 2014, 12:22:34 PM
When the earlier portions of DE 1 first opened, the exit numbers were originally mile-marker based but then changed to kM-based exit numbers shortly thereafter. IIRC, the highest exit number (near or at I-95) used to be just over 100; then it jumped to the 160s.
Hm. I didn't know that. But why would they change it to kilometers?
There was a short-lived push in 1993-1994 nationwide to revive & implement the Metric System. DelDOT probably thought changing the exit numbers on a new road before it was fully-completed was a cost-effective way to implement such. When the push to Metric all but died in 1995; so did efforts to further implementing such on existing highways.
Florida's Turnpike used to have exit numbers in multiples of four, with the zero point at I-95 near Miami. This left room for the addition of new interchanges, but it switched to a mileage-based system around 1989.
On the Homestead Extension, they used mileage-based exit numbers. My guess is that they standardized the mileage...but there's a four-mile spur from I-95 to the Extension between the two segments that's out of sequence, so they have weird mile markers.
Quote from: formulanone on October 21, 2014, 07:19:01 PM
Florida's Turnpike used to have exit numbers in multiples of four, with the zero point at I-95 near Miami. This left room for the addition of new interchanges, but it switched to a mileage-based system around 1989.
And multiples of 5 north of exit 60 (SR 60). http://en.wikipedia.org/wiki/Florida%27s_Turnpike#Exit_list has them listed.
But even earlier it used 1-12 without skipping, then skipped 2 or 3 per interchange to the end.
1964 map (http://richesmi.cah.ucf.edu/omeka2/items/show/1383) (10 not yet built)
1967 map (http://richesmi.cah.ucf.edu/omeka2/items/show/1382) (10 filled in and 23 I-4 added)
Quote from: formulanone on October 21, 2014, 07:19:01 PM
I'm not sure what exit numbers were used on the Homestead Extension, but my guess is that it standardized mileage (somewhat) between the two segments.
I don't think it had any until the change.
Quote from: PHLBOS on October 21, 2014, 05:09:42 PM
Quote from: adventurernumber1 on October 21, 2014, 04:01:41 PM
Quote from: PHLBOS on October 21, 2014, 12:22:34 PM
When the earlier portions of DE 1 first opened, the exit numbers were originally mile-marker based but then changed to kM-based exit numbers shortly thereafter. IIRC, the highest exit number (near or at I-95) used to be just over 100; then it jumped to the 160s.
Hm. I didn't know that. But why would they change it to kilometers?
There was a short-lived push in 1993-1994 nationwide to revive & implement the Metric System. DelDOT probably thought changing the exit numbers on a new road before it was fully-completed was a cost-effective way to implement such. When the push to Metric all but died in 1995; so did efforts to further implementing such on existing highways.
This would also explain the kilometer posts present for a few years on US 431 in Alabama back in the mid-90s, especially since significant portions south of Phenix City had just been moved onto a new four-lane alignment anyway.
QuoteThis would also explain the kilometer posts present for a few years on US 431 in Alabama back in the mid-90s, especially since significant portions south of Phenix City had just been moved onto a new four-lane alignment anyway.
As I recall, I-20/59 west of Birmingham had kilometer posts that survived into the early 2000s.
Regarding the topic, US 65 in Minnesota begins at Milepost 300 at the IA/MN line. This is due to MN 65 (whose mileposts begin at zero).
The MN 62 in/near Minneapolis begins near MP 104. This is for two reasons: first, to avoid milepost duplication with the MN 62 near Windom, and secondly, the mileposts reflect mileage from Hennepin County's original plan (back when it was a county state-aid route) to loop 62 west and north to today's MN 7/CSAH 101 intersection in Minnetonka.
US 75's mileage in Iowa is still based on it beginning in Council Bluffs, which it hasn't done since 1982.
No one here did mention that the Garden State Parkway in attempts to eliminate alphabet soup is one off on exit number to mileposts. For example the 136 mile post is at Exit 135, the 124 milepost is at the Cheesquake Service Area south of Exit 123, and the 140 milepost is even two off as it is situated at Exit 138.
Quote from: roadman65 on October 22, 2014, 07:43:26 AM
No one here did mention that the Garden State Parkway in attempts to eliminate alphabet soup is one off on exit number to mileposts. For example the 136 mile post is at Exit 135, the 124 milepost is at the Cheesquake Service Area south of Exit 123, and the 140 milepost is even two off as it is situated at Exit 138.
One reason for nobody mentioning the GSP would be that those listed oddities are too subtle to be noticed.
Truth be told, with the exception of your listed-Exit 138 at MM 140; your other two-listed examples of having a numeric difference of
1 between the nearest mile marker and the interchange is not unique to the GSP. It's been done on other highways in other states as well.
Quote from: roadman65 on October 22, 2014, 07:43:26 AM
No one here did mention that the Garden State Parkway in attempts to eliminate alphabet soup is one off on exit number to mileposts. For example the 136 mile post is at Exit 135, the 124 milepost is at the Cheesquake Service Area south of Exit 123, and the 140 milepost is even two off as it is situated at Exit 138.
That's hardly unusual.
There's many exits in NJ that don't line up perfectly with their milepost #.
In Maryland, I-95's Exit 100 is located at approximately MP 99.6.
Exit 1 in many states is located below MP 1.
Besides, these aren't milepost scheme issues.
Quote from: PHLBOS on October 22, 2014, 01:03:36 PM
Quote from: roadman65 on October 22, 2014, 07:43:26 AM
No one here did mention that the Garden State Parkway in attempts to eliminate alphabet soup is one off on exit number to mileposts. For example the 136 mile post is at Exit 135, the 124 milepost is at the Cheesquake Service Area south of Exit 123, and the 140 milepost is even two off as it is situated at Exit 138.
One reason for nobody mentioning the GSP would be that those listed oddities are too subtle to be noticed.
Truth be told, with the exception of your listed-Exit 138 at MM 140; your other two-listed examples of having a numeric difference of 1 between the nearest mile marker and the interchange is not unique to the GSP. It's been done on other highways in other states as well.
Not if you are going the other way. For example the Milepost 124 is located south of Exit 123 and not north of it. The mile 99.6 for I-95 in MD is correct as its one half mile to the actual 100 milepost. It normally goes to the nearest whole mile marker and usually in progression of how the numbers go. Yes different states use different methods I will admit, but the GSP Parkway is most unique in this fashion.
In addition the GSP has in many places (look at the ACE cloverleaf) with Exit 38 and Exit 38A instead of Exit 38A & B like everybody else. Then Exit 143 A and B with A being north of B. Letters too go from South to North like numbers do, and the same with Exit 4A being for NJ 47 North in Lower Township and Exit 4B being for NJ 47 South with the former being the first SB exit and the latter for the second. Again they should be (and are not) reveresed.
Part of Mass. 2A is in smoots.
Quote from: Eth on October 21, 2014, 07:50:05 PM
Quote from: PHLBOS on October 21, 2014, 05:09:42 PM
Quote from: adventurernumber1 on October 21, 2014, 04:01:41 PM
Quote from: PHLBOS on October 21, 2014, 12:22:34 PM
When the earlier portions of DE 1 first opened, the exit numbers were originally mile-marker based but then changed to kM-based exit numbers shortly thereafter. IIRC, the highest exit number (near or at I-95) used to be just over 100; then it jumped to the 160s.
Hm. I didn't know that. But why would they change it to kilometers?
There was a short-lived push in 1993-1994 nationwide to revive & implement the Metric System. DelDOT probably thought changing the exit numbers on a new road before it was fully-completed was a cost-effective way to implement such. When the push to Metric all but died in 1995; so did efforts to further implementing such on existing highways.
This would also explain the kilometer posts present for a few years on US 431 in Alabama back in the mid-90s, especially since significant portions south of Phenix City had just been moved onto a new four-lane alignment anyway.
I've seen a few scattered kilometer posts in Alabama, one on US 29 northeast of Troy and another along AL 17 somewhere south of I-20. They seemed to be placed quite far off to the extreme ROW limits, as if on purpose.
Quote from: jeffandnicole on October 22, 2014, 02:03:08 PM
Quote from: roadman65 on October 22, 2014, 07:43:26 AM
No one here did mention that the Garden State Parkway in attempts to eliminate alphabet soup is one off on exit number to mileposts. For example the 136 mile post is at Exit 135, the 124 milepost is at the Cheesquake Service Area south of Exit 123, and the 140 milepost is even two off as it is situated at Exit 138.
That's hardly unusual.
There's many exits in NJ that don't line up perfectly with their milepost #.
In Maryland, I-95's Exit 100 is located at approximately MP 99.6.
Exit 1 in many states is located below MP 1.
Besides, these aren't milepost scheme issues.
No, that's just a fear of the number zero.
Zerophobia?
Quote from: formulanone on October 22, 2014, 04:53:08 PM
I've seen a few scattered kilometer posts in Alabama, one on US 29 northeast of Troy and another along AL 17 somewhere south of I-20. They seemed to be placed quite far off to the extreme ROW limits, as if on purpose.
Alabama was one of the few states to actually make some progress on metrication; the guide signs on the original US 78/I-22 Jasper bypass section (from current AL 118 to AL 269) were originally signed using metric distances and exit numbers, but have since been patched over or replaced. See e.g. http://www.lordsutch.com/roads/us78/newer/6.html
MA 128 has a "secret" set of mileposts between Canton and Peabody where it runs concurrent with I-95 - the posted mileposts reflect the I-95 mileage. This is why, when 128 separates from I-95, the first milepost you see reads 37.2 instead of 0.2.
FL 429 to avoid the zero factor has Exit 1 for its southern terminus, but Exit 1A at th7e first exit close to actual MM 1.
Some places like NJ and IL uses the other interstate's numbering scheme to avoid this hence Exit 60 on I-195 and NJ 29 at their zero ends. Also I-24 western terminus uses I-57's mileage for both the I-57 exit to I-24 and from I-24 to both ramps to I-57.
Aren't there some funky mile markers on I-40 just inside the Tennessee state line in Memphis?
I seem to remember the exits were...a bit off the last I was there. Probably something to do with the rerouting of I-40 around Memphis' north side. As I recall, the I-40 exit with I-240 and Sam Cooper were marked Exit 12, and then the exit to the east of I-240 along I-40 was also Exit 12. I don't remember the mile markers around there but this is odd. Again, I'm sure the reason is for the rerouting.
Quote from: roadman on October 22, 2014, 07:54:36 PM
MA 128 has a "secret" set of mileposts between Canton and Peabody where it runs concurrent with I-95 - the posted mileposts reflect the I-95 mileage. This is why, when 128 separates from I-95, the first milepost you see reads 37.2 instead of 0.2.
For a few years during the 80s, when the DPW posted mile-marker placards on overpass/underpass structures that showed to the second decimal place (100ths) it was based on Mile 0 along 128 being located near/at the Exit 44B (old 30B) ramp for US 1 North and increasing north/eastward. Some of which still remain to this day. I'm not sure if the stand-alone mile markers along that stretch of 128 ever reflected such.
Overpass mile marker 3.71 along MA 128 southbound at the MA 114 interchange (Exits 25A-B) (https://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Peabody,+MA&aq=0&oq=peabod&sll=40.002498,-75.118033&sspn=0.376076,0.602188&vpsrc=6&t=h&ie=UTF8&hq=&hnear=Peabody,+Essex+County,+Massachusetts&ll=42.540196,-70.937852&spn=0.000016,0.009409&z=17&layer=c&cbll=42.540118,-70.937949&panoid=8Rbp9Tw67e6h0lMJoxsxXg&cbp=12,259,,0,5.75) vs. MM 39.8 located just northeast of the MA 114 overpass (https://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Peabody,+MA&aq=0&oq=peabod&sll=40.002498,-75.118033&sspn=0.376076,0.602188&vpsrc=6&t=h&ie=UTF8&hq=&hnear=Peabody,+Essex+County,+Massachusetts&ll=42.540394,-70.937583&spn=0.000016,0.009409&z=17&layer=c&cbll=42.540431,-70.937531&panoid=Dl3YDGJwuN-_gpvrEFqzQg&cbp=12,236.09,,0,8.11)
I'm even more surprised that those (the structure MM placards) weren't reset when the I-95 North interchange was finally completed a few short years later or weren't set up that way (0 at the then-theoretic I-95 North break-off) when I-95 was re-routed onto most of 128. The interchange and ramp layout were on paper
years before ground was actually broken to build it.
Had MM 0 for 128 been reset at where I-95 breaks off/merges; then the fore-mentioned MM 39.8 near MA 114 would be MM 2.7-2.8* (the overpass placard would be MM 2.6 or 2.7*-something).
*IMHO, the current 128 MM 37.2 would actually be unsigned MM 0.1 if MM 0 were set at the fore-mentioned location.
One could recite what the mile-marker-based 128 interchanges from Peabody to Gloucester would/should be; but that's another topic for another thread.
Quote from: roadman65 on October 22, 2014, 08:45:32 PM
FL 429 to avoid the zero factor has Exit 1 for its southern terminus, but Exit 1A at th7e first exit close to actual MM 1.
Some places like NJ and IL uses the other interstate's numbering scheme to avoid this hence Exit 60 on I-195 and NJ 29 at their zero ends. Also I-24 western terminus uses I-57's mileage for both the I-57 exit to I-24 and from I-24 to both ramps to I-57.
Not always. I-24's end (https://www.google.com/maps?ll=37.599145,-88.991457&spn=0.0051,0.010568&t=h&z=17&layer=c&cbll=37.59922,-88.991552&panoid=oHvP7s0hYN1YXv97sXSjXg&cbp=12,309.19,,0,-0.09) is an oddity in Illinois. Other interstates and freeways have an Exit 0. I-474 (https://www.google.com/maps?ll=40.733625,-89.671472&spn=0.004878,0.010568&t=h&z=17&layer=c&cbll=40.733704,-89.671433&panoid=Otbdxg0mtFTbpodG4gFeFA&cbp=12,17.15,,0,-0.27)/IL-6 (https://www.google.com/maps?ll=40.748974,-89.669963&spn=0.003448,0.005284&t=h&z=18&layer=c&cbll=40.748974,-89.669963&panoid=pOQG-pmqlNA9Axs_BKrqKA&cbp=12,150.5,,1,-4.93) share an Exit 0, marked as Exits A and B. I-355, I-155 (https://www.google.com/maps?ll=40.183611,-89.414635&spn=0.009836,0.021136&t=h&z=16&layer=c&cbll=40.183348,-89.41871&panoid=Myipmqpa7nF-YOmIfqTNiA&cbp=12,174.6,,2,-4.04), and I-172 (https://www.google.com/maps?ll=39.75838,-91.302557&spn=0.002474,0.005284&t=h&z=18&layer=c&cbll=39.75838,-91.302557&panoid=3_bNcZHFj69U0RNoLoQrTA&cbp=12,127.06,,0,-10.1) have an Exit 0 as well. I-290's (https://www.google.com/maps?ll=42.044992,-88.029866&spn=0.00478,0.010568&t=h&z=17&layer=c&cbll=42.044992,-88.029866&panoid=TSCk0C4p9XV52sVclHuWQg&cbp=12,19.14,,1,-2.74) ends lack exit numbers, as does I-39's (https://www.google.com/maps?ll=40.54751,-89.003077&spn=0.009783,0.021136&t=h&z=16&layer=c&cbll=40.547413,-89.003087&panoid=YWM4AamoT6rI1_CifD3T9A&cbp=12,178.95,,1,-3.34) south end. IL-255 (https://www.google.com/maps?ll=38.76787,-90.043994&spn=0.00251,0.005284&t=h&z=18&layer=c&cbll=38.7678,-90.04399&panoid=-xXBAKQCtLqozzf0yW6Gjg&cbp=12,176.93,,1,-6.08) uses I-255's exit number (30). I-88 (https://www.google.com/maps?ll=41.535575,-90.348086&spn=0.004819,0.010568&t=h&z=17&layer=c&cbll=41.535573,-90.347863&panoid=Oj6iL8G9fyZGBCMK5V-5vA&cbp=12,94.08,,0,-1.19) uses Exit 1. I-180 (https://www.google.com/maps?ll=41.395533,-89.382755&spn=0.002415,0.005284&t=h&z=18&layer=c&cbll=41.395533,-89.382755&panoid=Z15K12LsW6oZGhPzHIdpmw&cbp=12,1.22,,1,-5.62) does not have exit numbers. I-294 uses I-80's exit number westbound (https://www.google.com/maps?ll=41.577892,-87.5417&spn=0.004815,0.010568&t=h&z=17&layer=c&cbll=41.577892,-87.5417&panoid=c6mUqoKAeB0PcWGn0Mcs1g&cbp=12,274.96,,0,-6.49) (160), but it is concurrent with I-80 at that point; but lacks an exit number eastbound (https://www.google.com/maps?ll=41.577708,-87.592524&spn=0.004815,0.010568&t=h&z=17&layer=c&cbll=41.577701,-87.592421&panoid=MlnAGwmppa7qs-qOoVuxEA&cbp=12,96.85,,1,-7.4). That may change when the Tri-State Tollway gets exit numbers. I-190 just merges into I-90 inbound.
I-355 (not on GSV yet):
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi837.photobucket.com%2Falbums%2Fzz298%2Fmidamcrossrds%2F100_3709_zpsded1396d.jpg&hash=2dd2be369b36d2616e9a53cbfbe1e8e900e79021) (http://s837.photobucket.com/user/midamcrossrds/media/100_3709_zpsded1396d.jpg.html)
Quote from: J N Winkler on October 21, 2014, 01:25:50 PM
Bit of trivia: in its documentation, TxDOT uses US 82 across Texas as an example of the reference marker system in operation. Lowest marker value is 220 at the Yoakum County line (western edge of the Texas Panhandle) and highest marker value is 798 in Texarkana. This is a difference of 578 miles. However, Google Maps gives the length of US 82 across Texas as 565 miles. Where did the extra 13 miles go?
(Edit--Wxfree's post, which came through as I was composing this one, offers a possible explanation for the 13-mile discrepancy.)
The usual reason for milepost discrepancies like this is concurrencies having their mileposts measured along the other route, but that would seem to not be the case here, since extra mileage is accrued. Another option could be a realignment. wxfree's idea is also a possibility.
Quote from: hbelkins on October 22, 2014, 09:54:05 PM
Aren't there some funky mile markers on I-40 just inside the Tennessee state line in Memphis?
Found some of my photos:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.millenniumhwy.net%2F2010_DFW_Day_1%2FImages%2F289.jpg&hash=bdc40cac3468cdc3bad224353a5d46d03805b409)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.millenniumhwy.net%2F2010_DFW_Day_1%2FImages%2F290.jpg&hash=48f5b917df36b7f58a01454bf232318a8bd6bcc8)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.millenniumhwy.net%2F2010_DFW_Day_1%2FImages%2F293.jpg&hash=e75a7f4afe7222f64ba8103b9d32c7561e974441)
As someone already mentioned, many numbered highways in Arizona carry over the mileage sequence from when two numbered highways branch off. I-17 inherited its numbering from when AZ 69 used to come into Phoenix.
Currently US 93 starts at zero at the Nevada border, and numbers increase as you go south.
Most of Wyoming's non-Interstates (particularly the US highways) have oddball mileposting, because the mileposts are done relative to maintenance control route numbers, not the signed highway numbers.
Also along those lines (and not mentioned yet): mileposts along US highways in Alabama are based on the underlying (mostly) hidden state route. So, taking US 45 as an example, you have two "Milepost 5" along it...one on the AL 17 stretch (in Prichard), and another on the AL 57 stretch (near Washington CR 20).
Virginia had a policy at one point where controlled-access bypasses built along the arterial system had milemarkers included, with "Milepost 0" being at the start of the bypass segment. This is why there's a MP 0 on US 60 near Fort Story...I recall also seeing them on a couple of the US 23 bypasses and maybe US 19/460 near Tazewell.
Vermont technically has "mileposts" along its non-Interstate routes...in the form of the reference markers, with mileage listed on the bottom line. The catch is that mileage resets at town lines. Class 2 town highways that are also Federal/state aid also have these reference markers/"mileposts".
Also in Vermont, while the Interstates have been switched over to full-size 0.2 mile markers over the past 5 years, they still retain the old, tiny 0.05 mile markers. However, I've noticed that VTrans hasn't been replacing lost or missing milemarkers.
Non-interstates in Arkansas change to 0.00 at county lines or significant intersections (US 412 rolls over at AR 23 near Huntsville).
I've noticed AR 59 is posted North to South, as opposed to South to North as most US Highways are.
NY also uses a reference marker system that resets at county and city lines. The milemarkers on freeways are essentially just for show (except the Thruway since NYSTA doesn't use reference markers).
Quote from: swbrotha100 on October 25, 2014, 09:33:42 PM
Currently US 93 starts at zero at the Nevada border, and numbers increase as you go south.
I was wondering why the exit on the Hoover Dam Bypass was numbered 2.
US 93's in Arizona aren't really that unusual. Arizona's mileposts increase west to east and south to north. US 93 enters the state along the western border.
Quote from: dfwmapper on October 26, 2014, 04:45:48 PM
US 93's in Arizona aren't really that unusual. Arizona's mileposts increase west to east and south to north. US 93 enters the state along the western border.
US 93 between Kingman and the Nevada border (Hoover Dam) was once part of US 466, and original AZ 69:
http://arizonaroads.com/arizona/az69.html
If/when US 93 in Arizona becomes I-11, it will be interesting to see if the mileposts are changed, or if everything virtually carries over like current I-17.
Two pointless short spurs in SD have mileage that starts from 93 and 53. I have no idea why.
Quote from: vdeane on October 26, 2014, 02:08:01 PMI was wondering why the exit on the Hoover Dam Bypass was numbered 2.
Both are - about 3 or 4 miles apart - you'd have thought that they'd have tweaked one to be 1 so you don't get two exit 2s close together.
The A1 in England is odd - at 100km from London, the numbers reset. Then at Blyth, Blyth becomes the datum point through (roughly) Yorkshire, then London once more becomes the datum.
With Driver Location Signs (http://www.cbrd.co.uk/articles/driver-location-signs/) its easier to see. Some roads are marked as if they are sliproads, even if they have their own number and datum point eg "M26 K 5.0". Spurs/routes that branch off either do or don't have their own numbering. The M4 Heathrow Spur has chainage marked as 'ASxx (https://maps.google.com/maps?ll=51.482866,-0.448744&spn=0.008699,0.021136&t=m&z=16&layer=c&cbll=51.482965,-0.452838&panoid=nV8kUNsMZCui5NwVW0Fe_Q&cbp=12,323.81,,2,1.23)' where xx is chainage in hectometres (to save the space of a decimal point) from the north end.
We have a sensible idea where routes that start near the coast and have even the slightest possibility of extension have their datum at the coast, unless they can have it at London.
Quote from: froggie on October 26, 2014, 08:48:02 AM
Virginia had a policy at one point where controlled-access bypasses built along the arterial system had milemarkers included, with "Milepost 0" being at the start of the bypass segment. This is why there's a MP 0 on US 60 near Fort Story...I recall also seeing them on a couple of the US 23 bypasses and maybe US 19/460 near Tazewell.
Don't recall seeing them on either route, but I could be mistaken. US 23 now has a system of mile markers that starts at 0 at the Tennessee state line and runs all the way to just south of Pound. Don't know why they were not installed all the way to the Kentucky line.
Some of of the limited-access bypasses do have sequential exit numbers that reset at each bypass.
I drove a route with unusual mile markers today; that being TN 68 between Ducktown (the US 64/74 interchange) and Madisonville (the US 411 interchange). The route is signed as a north-south route, but the mile markers start at 0 at the northern county line, not the southern one. It's almost as if TN 68 was once signed as an east-west route and the mile markers are still configured that way.[/list]
The exit numbers on I-580 here in California, when used, increase as travel east, as appropriate for an east-west route, However, the postmiles run opposite, increasing as you travel west. This is because I-580 was previously designated as north-south I-5W, and the piece of I-580 between Richmond and San Rafael was formerly designated as north-south CA-17. Northbound 5W and northbound 17 are now westbound 580.
Quote from: swbrotha100 on October 26, 2014, 06:05:53 PM
Quote from: dfwmapper on October 26, 2014, 04:45:48 PM
US 93's in Arizona aren't really that unusual. Arizona's mileposts increase west to east and south to north. US 93 enters the state along the western border.
US 93 between Kingman and the Nevada border (Hoover Dam) was once part of US 466, and original AZ 69
The oddity there is that US 93 is a north-south route but is mile posted north to south. But if US 93 gets its mileposts from old US 466 (which was east-west and could have been mile posted west to east starting at the Nevada state line), that would make some sensible explanation–although I'm surprised it hasn't been changed since US 466 has been decommissioned for some time.
Quote from: english si on October 26, 2014, 07:43:28 PM
Quote from: vdeane on October 26, 2014, 02:08:01 PMI was wondering why the exit on the Hoover Dam Bypass was numbered 2.
Both are - about 3 or 4 miles apart - you'd have thought that they'd have tweaked one to be 1 so you don't get two exit 2s close together.
The exit 2 on the Nevada side falls at the normal mile post location, and would stay there when I-11 comes through. The Arizona one would definitely be renumbered.
Quote from: roadfro on October 28, 2014, 12:26:49 AM
The Arizona one would definitely be renumbered.
Not sure I agree. Numbering it north to south (or west to east) as an Interstate makes a lot of sense when you consider that the north segment (Nevada to I-40) can probably be upgraded and ready for designation as an Interstate a decade or more before anything else is ready. Plus, there's no real consensus as to the routing south of Wickenburg, or where the southern terminus will actually be (I-10 at Buckeye? AZ 30? I-10/I-8 at Casa Grande? I-10 near Vail?).
Quote from: dfwmapper on October 28, 2014, 05:33:52 AM
Quote from: roadfro on October 28, 2014, 12:26:49 AM
The Arizona one would definitely be renumbered.
Not sure I agree. Numbering it north to south (or west to east) as an Interstate makes a lot of sense when you consider that the north segment (Nevada to I-40) can probably be upgraded and ready for designation as an Interstate a decade or more before anything else is ready. Plus, there's no real consensus as to the routing south of Wickenburg, or where the southern terminus will actually be (I-10 at Buckeye? AZ 30? I-10/I-8 at Casa Grande? I-10 near Vail?).
When this section becomes I-11, the exit numbering would be required to go south to north since it will be a north/south Interstate–that's an MUTCD rule they likely won't get around. By the time any major traction starts happening on the I-11 corridor, Arizona should have a rough-enough alignment selected that they can figure out the mileage for an exit number near the Nevada line. (The only wrench in that plan is if an extension south of Phoenix becomes reality...)
The photos hbelkins posted made me think of the mileposts at the Wilson Bridge and on the surrounding roads. I don't have any good pictures of them, but the quad-carriageway design of the Beltway there caused them to use some interesting mileposts denoting the carriageway, which loop (Outer or Inner), and mileage; some of the exit ramps have additional detail.
For example, "OLL [horizontal underscore] MILE 175 [horizontal underscore] .2" may be seen at this Street View link: http://goo.gl/maps/xup4e
Here's a milepost for an on-ramp: http://goo.gl/maps/QRpcy ("NH" denotes "National Harbor," a commercial development just to the south) I note Maryland uses a dash in "IL-L," which I think makes it more legible.
Obviously the intent is to allow for precise location of any incidents when dispatching emergency response to what is a rather complex little area.
NJ 55 starts at mile 20, but that's due to an unbuilt portion, which might get built eventually. I-95 north of the NJ Turnpike's terminus continues Turnpike mileage, but the exit numbers are based on mileage which will never be correct due to unbuilt portions of I-95 and the impending rerouting. I-78 mile numbers reset to zero at the NJ Turnpike. The Palisades Parkway does not reset its mileage at the New York state line.
Quote from: bzakharin on October 30, 2014, 09:37:52 AM
NJ 55 starts at mile 20, but that's due to an unbuilt portion, which might get built eventually. I-95 north of the NJ Turnpike's terminus continues Turnpike mileage, but the exit numbers are based on mileage which will never be correct due to unbuilt portions of I-95 and the impending rerouting. I-78 mile numbers reset to zero at the NJ Turnpike. The Palisades Parkway does not reset its mileage at the New York state line.
NJ 18 starts at exit 6 for the same reason. But the remaining portion. Will never be built
Arizona
AZ Loop 303 Starts at 104 (Junction I-10) (The route is planned to continue South of I-10 103 Miles? to Future I-11)
I-17 Starts at 194 (I-10/I-17 Split)
US 60 Starts At 31 (Junction I-10 Brenda)
As for I-11 Mile Markers will Need to change once the Hoover Dam to Wickenberg (US-93 (old US-466) with I-40 Overlap) and Wickenberg to Tucson (New Construction with possible I-10 & I-8 overlaps) Segments are Complete (Date Unknown)
Quote from: mapman1071 on November 02, 2014, 12:40:53 AM
Arizona
AZ Loop 303 Starts at 104 (Junction I-10) (The route is planned to continue South of I-10 103 Miles? to Future I-11)
I-17 Starts at 194 (I-10/I-17 Split)
US 60 Starts At 31 (Junction I-10 Brenda)
As for I-11 Mile Markers will Need to change once the Hoover Dam to Wickenberg (US-93 (old US-466) with I-40 Overlap) and Wickenberg to Tucson (New Construction with possible I-10 & I-8 overlaps) Segments are Complete (Date Unknown)
I believe 303 is numbered backwards from its eastern terminus at I-17, which would be right around MP 139, and is indeed somewhere between 135 and 140 miles from the California border depending on where it's measured from. We'll just pretend it isn't signed N/S for the entire length. The distance from the Mexican border isn't correct at either end, even with an eventual extension south to I-11.
I-17 inherited its mileposts from AZ 69 which picked them up from its intersection with US 89.
US 60's mileposts date back to the original 1930s routing when it ran all the way to the state line and on to LA.
I-10 basically took over the old US 60 alignment west of Brenda. US 60 is just one example of mileposts carrying over on some highways in Arizona.
Funny thing about Loop 303. The original mileposts started in single digits. I think just before the major upgrade began, 100 was added to the existing mileposts.
NH 101, the freeway east of I-93 out of Manchester, the mile markers start at 100 instead of the 50-something it should be.