Highways with unusual milepost schemes

[froggie]

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.

[US71]

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.

[vdeane]

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).

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.

[dfwmapper]

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.

[swbrotha100]

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.

[SD Mapman]

Two pointless short spurs in SD have mileage that starts from 93 and 53. I have no idea why.

[english si]

I 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 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' 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.

[hbelkins]

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]

[jrouse]

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.

[roadfro]

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.

I 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.

[dfwmapper]

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?).

[roadfro]

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...)

[1995hoo]

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.

[bzakharin]

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.

[jwolfer]

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

[mapman1071]

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)

[dfwmapper]

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.

[swbrotha100]

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.

[SectorZ]

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.