Milepost signs

[cpzilliacus]

There is a lot of variability regarding these. 

Interstate highways in Virginia  usually have then every 1/10th of a mile.   

As do some freeway-class roads in Pennsylvania (but there are also many of those that do not).  On "free" roads, Maryland does not normally use 1/10th of a mile mileposts, but they  are nearly always used on toll-maintained highways and crossings. 

Turnpikes in Pennsylvania and New Jersey have 1/10th of a mile usually.

I have seen some states (Kansas, I believe) that post a mile marker every  2/10th of a mile.

I think posting them every 1/10th of a mile is good for reporting problems  with the  road, as well as for  getting emergency  responders to the correct locations. 

Your thoughts?

[MNHighwayMan]

Some select Twin Cities freeways in Minnesota have 1/10th mile markers, posted in the median/divider. They look like this. These are in addition to the standard whole-mile markers on the side of the road.

In the Des Moines area, all three Interstates, as well as the freeway sections of US-65 and IA-5, have 1/10th mile markers posted.
They look like this. These are posted on either the side of the road or in the median, depending on location (there doesn't seem to be a discernible pattern for placement, as far as I can tell.) For the ones posted at the side, the whole miles are marked with just standard markers. In the case of median-posted markers, both are usually present. Waterloo has something similar on the freeway portion of US-218, and I imagine that it's possible they exist in Iowa's other urban areas too (can't say for sure because I either don't remember or haven't been there.)

However, outside of those urban areas, both Minnesota and Iowa only use whole-mile markers.

[Techknow]

In California, Caltrans don't have Milepost signs, instead they have postmile markers! I have noticed that the consistency of them varies greatly from district to district. In the Bay Area (District 4), they are relatively rare and what markers are there are old. Interstate 280 has a handful mainly by certain on-ramps. I have noticed when you reach the a county border you might see a few but after that once after a few miles, especially on US-101 south from Santa Clara to San Benito county, and San Benito to Monterey. On the other hand if you're heading to Yosemite via Highway 152 and 140 you'll see them exactly at once a mile for certain distances, but those are in Caltrans District 10.

[US 89]

Utah posts just the simple "MILE xxx"  sign every mile. However, within the past couple of months, in large confusing interchanges they have started posting signs like these every 0.1 of a mile:





Missouri also has the full mileposts with direction and shield every 0.2 of a mile, and I think Colorado also does something similar in urban areas only

[Hurricane Rex]

Oregon posts every mile except for OR 217 and US 26 between Sandy and Rihdadendron (misspelled) which are every half mile due to intersections/interchanges.

[hotdogPi]

Every 0.2 in Massachusetts on freeways and many state routes. Some state routes have them every mile only. In addition, sometimes, there are some VERY tiny diamonds that have mile markers to the tenth (0.1, not 0.2), not meant for the general public.

MA 110's mile markers between 37 and 54 (haven't checked outside this range) are about 2.5 miles above what they should be.

There is an older-style 42.5 mile marker (which is not a multiple of .2) on I-93 northbound that is between 42.2 and 42.4.

[Brandon]

Illinois, of course, is different depending on where you are.

ISTHA, every 1/4 mile: https://goo.gl/maps/4jnEVcUq3pK2
IDOT D1, old style (random to the hundredths of a mile on light posts): https://goo.gl/maps/ciU9hDjFR1s
IDOT D1, new style (every 1/2 mile): https://goo.gl/maps/3LCjjoobiF42
IDOT D8 (every 1/5 mile): https://goo.gl/maps/VYw1Gn18ZTp
Everywhere else uses the regular mileposts at 1 mile intervals.

[1995hoo]

I agree with cpzilliacus about how the tenths are useful for pinpointing incidents, although I have to say I find it really annoying when WTOP's traffic reporters insist on saying, for example, "mile 143 over 6." It's not a fraction!

[MNHighwayMan]

I agree with cpzilliacus about how the tenths are useful for pinpointing incidents, although I have to say I find it really annoying when WTOP's traffic reporters insist on saying, for example, "mile 143 over 6." It's not a fraction!

Well, it is a fraction... just not that fraction.

[1995hoo]

I agree with cpzilliacus about how the tenths are useful for pinpointing incidents, although I have to say I find it really annoying when WTOP's traffic reporters insist on saying, for example, "mile 143 over 6." It's not a fraction!

Well, it is a fraction... just not that fraction.

Technically I guess it's a "mixed number" ? (If I'm remembering grammar-school math classes correctly!)

[hotdogPi]

I agree with cpzilliacus about how the tenths are useful for pinpointing incidents, although I have to say I find it really annoying when WTOP's traffic reporters insist on saying, for example, "mile 143 over 6." It's not a fraction!

Well, it is a fraction... just not that fraction.

Technically I guess it's a "mixed number" ? (If I'm remembering grammar-school math classes correctly!)

A mixed number is e.g. 1½.
143/6 is an improper fraction, and 143.6 is a decimal.

[MNHighwayMan]

I agree with cpzilliacus about how the tenths are useful for pinpointing incidents, although I have to say I find it really annoying when WTOP's traffic reporters insist on saying, for example, "mile 143 over 6." It's not a fraction!

Well, it is a fraction... just not that fraction.

Technically I guess it's a "mixed number" ? (If I'm remembering grammar-school math classes correctly!)

A mixed number is e.g. 1½.
143/6 is an improper fraction, and 143.6 is a decimal.

And if we really wanna get into it, 143.6 can be written, in simplified fractional form, as 718/5.

[Eth]

Georgia:

Interstates in/near Atlanta (maybe other large cities too, not sure): every 0.2 miles (like the I-80 Utah example above)
Interstates away from Atlanta: generally every 1 mile, though I-985 has them every 0.5 miles (same)
Non-Interstates: "classic" style, every 1 mile. US routes don't have their own independent mileposts; they're based on the underlying state route, and they almost always reset at county lines (only exception I know of is GA 400).

[vdeane]

Most full miles in NY use either the classic design, enhanced markers, or a "NYSDOT classic" design.  Tenths are all over the place:
-Region 1 Classic (new installs use standard MUTCD; tenths only in Albany, Rensselaer, Saratoga, and Schenectady Counties excluding I-88 and NY 85)
-Region 2: None
-Region 3: enhanced tenths along NY 481, I-/NY 690, NY 5, and NY 695; standard tenths recently installed along I-81 south of Syracuse
-Region 4
-Region 5 Buffalo/Niagara Falls (enhanced tenths used on I-86)
-Regions 6 and 7: full miles only
-Region 8 (sometimes but not usually in all green similar to a standard marker)
-Region 9: enhanced tenths near Binghamton on I-81 and NY 17
-Regions 10 and 11: None
-Thruway

[MNHighwayMan]

Most full miles in NY use either the classic design, enhanced markers, or a "NYSDOT classic" design.  Tenths are all over the place:

Wow. Seems so strange to me that there's so much variance on something like this within a single state.

[1995hoo]

I agree with cpzilliacus about how the tenths are useful for pinpointing incidents, although I have to say I find it really annoying when WTOP's traffic reporters insist on saying, for example, "mile 143 over 6." It's not a fraction!

Well, it is a fraction... just not that fraction.

Technically I guess it's a "mixed number" ? (If I'm remembering grammar-school math classes correctly!)

A mixed number is e.g. 1½.
143/6 is an improper fraction, and 143.6 is a decimal.

Yeah, I meant 143-6/10 is a mixed number.

[cpzilliacus]

Yeah, I meant 143-6/10 is a mixed number.

If you work with computers and program in FORTRAN, that would be a real number. 

[bzakharin]

NJDOT recently switched to large mile markers with shields facing both directions every 0.2 miles on freeways, though I don't think everything is converted yet. For state and US routes that are not freeways it's large mile markers without shields every 0.5 miles. That's still definitely in the process of being implemented.

The Atlantic City Expressway has relatively small mile markers every 0.1 miles with shields on the full mile. However, some mile markers are much larger. Not sure why or which ones.

[wxfree]

I think frequent markers is a good idea.  I like most of what Texas does with roads, but location marking is very deficient.  I can understand not wanting to install frequent markers on such a vast system, but most of the markers we have don't even make sense.  Interstates get a marker every mile, which is good.  Non-Interstates get a very small "reference marker" under a highway shield (on both sides of the sign post) every two miles on alternating sides of the road, so that one side of the road has one every four miles.  The numbers increase by two from one to the next, using even numbers. The markers are too small to see at night unless you go by slowly, and are easy to miss.  Most people don't even know they exist.  They don't reflect the distance from the beginning of the road and don't always accurately reflect the distance between them.  Some are less than a half-mile from the last one and still show the next even number.  So few people know about them that they're nearly useless.

NTTA roads have frequent markers, but not tenth-miles.  They have a marker every 500 feet (whose idea was that?) and they don't start at zero.  They're 2, 3, and 4 digit numbers ending in 0 and 5.  If you multiply the number by 100 and subtract the number at the beginning of the road, you'll have your distance from that point, in feet.  They're installed on the left barrier.  If the road has a median and the barrier is at the edge of the road on the other side of the median, then you can't see the markers.  They seem to be installed primarily for the benefit of road crews.

[Roadwarriors79]

Is California the only state that lacks standard milepost signs? I would hope that one day they would consider adding them to their interstate highways. As far as some of the other states go, it would be nice to have mile markers on some of the non-interstate highways.

[US 89]

Is California the only state that lacks standard milepost signs? I would hope that one day they would consider adding them to their interstate highways. As far as some of the other states go, it would be nice to have mile markers on some of the non-interstate highways.

Nevada uses white mileposts that reset at county lines, similar to California. On interstates, the standard green mileposts with statewide mileage (which NDOT calls "reference panels" ) are used in addition to the white mileposts.

[myosh_tino]

Is California the only state that lacks standard milepost signs? I would hope that one day they would consider adding them to their interstate highways. As far as some of the other states go, it would be nice to have mile markers on some of the non-interstate highways.

Yes primarily because exit numbering only became a thing in California around the year 2000.  Green milepost sign were installed on a portion of CA-58 between Bakersfield and Boron and on US 6 about 10 or so years ago but were removed because they caused confusion with emergency responders.

We had a discussion about the removal of the green mileposts in California in the Pacific Southwest board at https://www.aaroads.com/forum/index.php?topic=18780.msg2173449#msg2173449

[vdeane]

Seriously, it shouldn't have been hard for them to make a database matching the milepost with the corresponding postmile.  Just another example of CalTrans incompetence. 

If I had my way, it would be a "shall" requirement in the federal MUTCD for all freeways longer than a mile to have mileposts.  Tenths would be a "should" requirement within urbanized areas and "may" everywhere else.

EDIT: I'd also require that all distance measurements and exit number be based on the same units.  Roads with everything in miles but km-based exit numbers drive me crazy (I'm looking at you, DE 1).

[roadfro]

Seriously, it shouldn't have been hard for them to make a database matching the milepost with the corresponding postmile.  Just another example of CalTrans incompetence. 

If I had my way, it would be a "shall" requirement in the federal MUTCD for all freeways longer than a mile to have mileposts.  Tenths would be a "should" requirement within urbanized areas and "may" everywhere else.

Well, I'm pretty sure the database itself exists, since CalTrans had to calculate the mileage-based exit numbers when implementing the Cal-NExUS exit numbering plan. But the implementation of that plan did not involve installing standard mileposts with statewide cumulative mileage. They were only installing minimal exit numbers (exit gore sign + the advance exit sign) on interstates at first, and only really got moving on the plan through gradual sign replacement contracts or via major construction projects. (I think FHWA pressured CalTrans on the exit numbering issue, but gave them a pass on mileposts since just implementing numbering was a massive undertaking.)

I think mileposts serve a more important purpose as a locating tool rather than a navigational aid. So from that perspective, CalTrans' county-based postmile system works (assuming the panels are actually posted and are readable in the field). Where it breaks down is when you run into postmile equations and sections where the postmiles have letter prefixes due to realignments–the majority of the traveling public doesn't know how to interpret that.

From that perspective, I like what Nevada DOT is doing with their county-based mileposts on non-Interstates. As rural roads get rehabilitated/resurfaced/reconstructed or receive signing upgrades, NDOT is installing enhanced mileposts at every mile that are highly visible to the motoring public (more than twice the size of standard and posted higher off the ground) while still using the normal versions at county lines, junctions and structures. (Where NDOT can still improve though is mileposting in urban areas and along interstates...)

EDIT: Previous discussion of NDOT's new mileposts on the Pacific Southwest board a few years ago: https://www.aaroads.com/forum/index.php?topic=13429

[cpzilliacus]

I think mileposts serve a more important purpose as a locating tool rather than a navigational aid.

I agree. Especially for reporting emergencies and other incidents (property damage crashes and disabled vehicles) to the appropriate authority.