Enhanced Mile Markers

[SkyPesos]

I don't think I agree with showing both/all routes of an overlap especially since the mileage usually is only correct for one of them. (The I-71/75 in Ohio is a rare case that they do match) Georgia only includes the shield for the dominant route (example https://goo.gl/maps/S2JSGKddquAL41TW8 ).

Although this gives me the idea that there could be enhanced MM for both routes of an overlap, by having most of the MM be for the dominant route but when the lesser route reaches a whole number mile, remove the corresponding dominant MM and install a MM for the lesser route instead.

For example, route A is dominant, routes A & B have a multiplex that begins at mile 20.0 on A, mile 10.6 on B. So the mile markers could be "North A 20", "North A 20.2", "North B 11" (instead of A 20.4), "North A 20.6", etc

I agree with only showing one route on mile markers in a multiplex.

But if you had to post both, removing A when B reaches an integer mile point would be a bit weird. I'd suggest posting the A miles normally, with a small all-text placard beneath showing the equivalent B mileage at that point–this keeps the dominant mileage prominent and provides the secondary mile info.

So something like this? (I used random numbers in this sketch as it's not important to the main point.)

[roadfro]

I agree with only showing one route on mile markers in a multiplex.

But if you had to post both, removing A when B reaches an integer mile point would be a bit weird. I'd suggest posting the A miles normally, with a small all-text placard beneath showing the equivalent B mileage at that point–this keeps the dominant mileage prominent and provides the secondary mile info.

So something like this? (I used random numbers in this sketch as it's not important to the main point.)

Yeah, something like that, with the plaque being noticeably smaller.

[Scott5114]

I don't think I agree with showing both/all routes of an overlap especially since the mileage usually is only correct for one of them. (The I-71/75 in Ohio is a rare case that they do match) Georgia only includes the shield for the dominant route (example https://goo.gl/maps/S2JSGKddquAL41TW8 ).

Although this gives me the idea that there could be enhanced MM for both routes of an overlap, by having most of the MM be for the dominant route but when the lesser route reaches a whole number mile, remove the corresponding dominant MM and install a MM for the lesser route instead.

For example, route A is dominant, routes A & B have a multiplex that begins at mile 20.0 on A, mile 10.6 on B. So the mile markers could be "North A 20", "North A 20.2", "North B 11" (instead of A 20.4), "North A 20.6", etc

I agree with only showing one route on mile markers in a multiplex.

But if you had to post both, removing A when B reaches an integer mile point would be a bit weird. I'd suggest posting the A miles normally, with a small all-text placard beneath showing the equivalent B mileage at that point–this keeps the dominant mileage prominent and provides the secondary mile info.

Why not just post both full enhanced milemarkers next to each other at the integer mileage points according to the dominant route, with the recessive route showing a non-round milemarker?



While this is likely not appropriate on concurrencies that exist mostly to connect two disparate and unrelated sections of a minor highway, anyone who has a destination along the recessive route and is actually interested in following the recessive route through the concurrency is likely to find its mileposts more useful to them than the dominant route's.

[ran4sh]

The reason I didn't suggest posting both routes' mile markers at the same point is for message loading and/or sign spreading concerns. Two mile markers at the same point can be confusing in certain situations, for example, when reporting the location of an incident (i.e. if a 911 dispatcher asks a motorist where they are, do they read the content of both mile markers?)

[Scott5114]

The reason I didn't suggest posting both routes' mile markers at the same point is for message loading and/or sign spreading concerns. Two mile markers at the same point can be confusing in certain situations, for example, when reporting the location of an incident (i.e. if a 911 dispatcher asks a motorist where they are, do they read the content of both mile markers?)

Presumably they could read either marker and it should suffice. The only issue would be if someone read the shield for one marker and the mileage for another, but I don't know why anyone would think that was a desirable thing to do.

I'm not sure that message loading or sign spreading would be a concern in this situation, since it's not a problem when displaying two adjacent shields for concurrent highways. so I'm not sure why two adjacent milemarkers would be a concern, especially since people could focus on whichever one they're interested in.

[SkyPesos]

Found some 2021 GSV images on various Tennessee interstates, and along with my drive on I-40 east of Knoxville a few months ago, seems like the state replaced a lot of their old enhanced mile markers with new, slightly larger and more detailed, ones, similar to what Ohio has been slowly doing for years now:

[hbelkins]

I don't think I agree with showing both/all routes of an overlap especially since the mileage usually is only correct for one of them. (The I-71/75 in Ohio is a rare case that they do match) Georgia only includes the shield for the dominant route (example https://goo.gl/maps/S2JSGKddquAL41TW8 ).

Although this gives me the idea that there could be enhanced MM for both routes of an overlap, by having most of the MM be for the dominant route but when the lesser route reaches a whole number mile, remove the corresponding dominant MM and install a MM for the lesser route instead.

For example, route A is dominant, routes A & B have a multiplex that begins at mile 20.0 on A, mile 10.6 on B. So the mile markers could be "North A 20", "North A 20.2", "North B 11" (instead of A 20.4), "North A 20.6", etc

I agree with only showing one route on mile markers in a multiplex.

But if you had to post both, removing A when B reaches an integer mile point would be a bit weird. I'd suggest posting the A miles normally, with a small all-text placard beneath showing the equivalent B mileage at that point–this keeps the dominant mileage prominent and provides the secondary mile info.

Why not just post both full enhanced milemarkers next to each other at the integer mileage points according to the dominant route, with the recessive route showing a non-round milemarker?



While this is likely not appropriate on concurrencies that exist mostly to connect two disparate and unrelated sections of a minor highway, anyone who has a destination along the recessive route and is actually interested in following the recessive route through the concurrency is likely to find its mileposts more useful to them than the dominant route's.

Mile markers are posted for both US 13 and US 50 on the Salisbury, Md. bypass.

And I read over the weekend that mile markers for I-395 are being placed as a supplement to the mile markers for I-290 in Massachusetts.

Meanwhile, these have been posted along I-24 in the Paducah area. (Photo from KYTC District 1's Facebook page.)

[Bickendan]

Green 24?
Is there a business loop I'm not aware of?

[SkyPesos]

Green 24?
Is there a business loop I'm not aware of?

That is one of my two thoughts.
The other is "why is this one green when KY uses blue in the rest of the state?"

[hbelkins]

Green 24?
Is there a business loop I'm not aware of?

That is one of my two thoughts.
The other is "why is this one green when KY uses blue in the rest of the state?"

There is a signed Business Loop 24 in Paducah (formerly signed as Downtown Loop 24) but this is on the mainline interstate. Why they're green, I have no idea.

[ErmineNotyours]

Washington has sort-of adopted fractional mile markers on the northbound I-5 approach to Downtown Seattle.  The green mile makers with tenth of a mile divisions are used to identify variable speed limit sign gantries.  Example.

[Bickendan]

I like how it goes Mile 162 then Mile 162.0 

[adventurernumber1]

My first vivid memory of enhanced mile markers was that of the blue ones on Interstate 75 in Chattanooga, Tennessee when I was real young. From the get-go I had always associated these more with urban areas since I was used to the non-enhanced green markers on I-75 in Georgia closer to home.

I like the blue enhanced mile markers, but I might just slightly prefer the green ones, since the color is more consistent with mile markers across the board, and thus I inherently associate mile markers with the color green (despite having seen the blue enhanced ones in Chattanooga myriad times).

I'm not at all into that mile marker either...it indeed looks far too much like a business shield, they definitely should have used a regular red-and-blue-colored shield instead.     

[NoGoodNamesAvailable]

I was driving on Route 4 in NJ recently and called 911 to report a large car bumper sitting in the travel lanes that people were swerving around. NJ is pretty consistent about posting EMMs, so when I called I gave the route, direction, and mile marker. The operator replied that this information was "useless to her"  and asked me to give the town and a cross street. I'm not from Bergen county so I don't usually make note of which one of the 500 tiny municipalities I'm in at a given moment. I was able to give a cross street by retracing my location on google maps satellite view, but someone not as geographically minded or tech-savvy probably wouldn't be able to do that. If EMMs are really "useless"  to 911 operators when reporting an emergency, I don't know why NJ wastes their money installing them.

[SkyPesos]

I was driving on Route 4 in NJ recently and called 911 to report a large car bumper sitting in the travel lanes that people were swerving around. NJ is pretty consistent about posting EMMs, so when I called I gave the route, direction, and mile marker. The operator replied that this information was “useless to her” and asked me to give the town and a cross street. I’m not from Bergen county so I don’t usually make note of which one of the 500 tiny municipalities I’m in at a given moment. I was able to give a cross street by retracing my location on google maps satellite view, but someone not as geographically minded or tech-savvy probably wouldn’t be able to do that. If EMMs are really “useless” to 911 operators when reporting an emergency, I don’t know why NJ wastes their money installing them.

I had the complete opposite experience. When my dad driving got into a car crash, they had me call the 911 dispatcher (yes, a 14 year old back then), while they talked with the people in the other car involved. After I told them that the crash was on I-71, and we were parked in the median, I was about to give the two nearest exits, though the dispatcher asked me "do you see a blue mile marker nearby?". I did, and gave them the mile marker number, and that was all they needed (Cincinnati uses 0.1 intervals on enhanced mile markers, unlike most other urban areas I've been to, so that's pretty precise already).

[rower155]

I was driving on Route 4 in NJ recently and called 911 to report a large car bumper sitting in the travel lanes that people were swerving around. NJ is pretty consistent about posting EMMs, so when I called I gave the route, direction, and mile marker. The operator replied that this information was "useless to her"  and asked me to give the town and a cross street. I'm not from Bergen county so I don't usually make note of which one of the 500 tiny municipalities I'm in at a given moment. I was able to give a cross street by retracing my location on google maps satellite view, but someone not as geographically minded or tech-savvy probably wouldn't be able to do that. If EMMs are really "useless"  to 911 operators when reporting an emergency, I don't know why NJ wastes their money installing them.

I had the complete opposite experience. When my dad driving got into a car crash, they had me call the 911 dispatcher (yes, a 14 year old back then), while they talked with the people in the other car involved. After I told them that the crash was on I-71, and we were parked in the median, I was about to give the two nearest exits, though the dispatcher asked me "do you see a blue mile marker nearby?". I did, and gave them the mile marker number, and that was all they needed (Cincinnati uses 0.1 intervals on enhanced mile markers, unlike most other urban areas I've been to, so that's pretty precise already).

It is definitely not the norm if a 911 dispatcher says the milepost doesn't help them.  The Mile-1 app works well for knowing your mile marker, especially if you can't see the nearest one.
https://apps.apple.com/us/app/mile-1/id1562022453

[ethanhopkin14]

I was driving on Route 4 in NJ recently and called 911 to report a large car bumper sitting in the travel lanes that people were swerving around. NJ is pretty consistent about posting EMMs, so when I called I gave the route, direction, and mile marker. The operator replied that this information was "useless to her"  and asked me to give the town and a cross street. I'm not from Bergen county so I don't usually make note of which one of the 500 tiny municipalities I'm in at a given moment. I was able to give a cross street by retracing my location on google maps satellite view, but someone not as geographically minded or tech-savvy probably wouldn't be able to do that. If EMMs are really "useless"  to 911 operators when reporting an emergency, I don't know why NJ wastes their money installing them.

I had the complete opposite experience. When my dad driving got into a car crash, they had me call the 911 dispatcher (yes, a 14 year old back then), while they talked with the people in the other car involved. After I told them that the crash was on I-71, and we were parked in the median, I was about to give the two nearest exits, though the dispatcher asked me "do you see a blue mile marker nearby?". I did, and gave them the mile marker number, and that was all they needed (Cincinnati uses 0.1 intervals on enhanced mile markers, unlike most other urban areas I've been to, so that's pretty precise already).

It is definitely not the norm if a 911 dispatcher says the milepost doesn't help them.  The Mile-1 app works well for knowing your mile marker, especially if you can't see the nearest one.
https://apps.apple.com/us/app/mile-1/id1562022453

I have had a similar situation happen to me more than once, being a 911 operator saying mile markers on specific routes mean nothing to them.  They wanted an address. 

[vdeane]

I can't comment on 911 operators, but AAA roadside assistance almost never takes milemarkers.  They always want an address, even when such is far less precise.

[jeffandnicole]

I was driving on Route 4 in NJ recently and called 911 to report a large car bumper sitting in the travel lanes that people were swerving around. NJ is pretty consistent about posting EMMs, so when I called I gave the route, direction, and mile marker. The operator replied that this information was "useless to her"  and asked me to give the town and a cross street. I'm not from Bergen county so I don't usually make note of which one of the 500 tiny municipalities I'm in at a given moment. I was able to give a cross street by retracing my location on google maps satellite view, but someone not as geographically minded or tech-savvy probably wouldn't be able to do that. If EMMs are really "useless"  to 911 operators when reporting an emergency, I don't know why NJ wastes their money installing them.

One 911 operator doesn't mean that thousands of these signs are suddenly useless.  911 operators are used to drivers being disoriented and not having an idea where they are, so I'm sure they would've figured it out in short order.  Besides, if a crash - especially a fatal crash - resulted from that bumper, and it got out that the issue was called in but the operator told the caller the information was useless, that would probably be the last time that would ever be used as an excuse for not providing assistance.

Even if someone did live in the area, there are so many towns that it's not uncommon for an incorrect town to be mentioned at first, even by a local.  If they have time, they'll talk on the radio and figure out the true location of the issue.

[Rothman]

I can't comment on 911 operators, but AAA roadside assistance almost never takes milemarkers.  They always want an address, even when such is far less precise.

AAA is terrible at this regard.  I had a breakdown right at the Kaaterskill Falls Trailhead on NY 23A.  I told them that and the dispatcher insisted I give them a cross street, despite it being in the middle of nowhere.  Evetually, I just said NY 32 some miles east and that finally appeased him.

[CtrlAltDel]

I sometimes wonder if AAA, and perhaps even 911, just type what you tell them into Google Maps, and the computer takes it from there. And so, if Google Maps worked with mile markers and exit numbers and the like, these services would too.

[SkyPesos]

Crossposting this from the I-69 in Indiana thread, as there's a section in a KTC study on why enhanced mile markers were originally blue instead of green:

I took a quick run down to Martinsville this morning to see the newest section of I-69. As discussed earlier in this thread, the mile markers are very inconsistent in this stretch from the north end of section 5 up to SR 144. This is a summary of what I saw.

Location	Type	Color	Interval	Placement
Section 5 (existing I-69)	Standard (no shield or cardinal direction)	Green	.5 miles	Right shoulder
Between north end of section 5 and SR 39	Enhanced with no fractional number on full miles	Blue	.5 miles	Right shoulder
Martinsville new section (SR 39 to Morgan St.)	Enhanced	Green	.5 miles	Median
North of Morgan St. to MM 151	Enhanced	Blue	.5 miles	Right shoulder
From MM 151 north to SR 144	Enhanced	Blue	.2 miles	Right shoulder

The little mile markers that mark bridges were also green where the green enhanced reference markers existed in Martinsville. That makes me think the green ones are a mistake.

I Googled trying to find some of the history behind the history of the enhanced reference markers. This report on the evaluation of reference markers describes some of the issues and discussions that occurred back in the late 1990s. This particular document is from the Kentucky Transportation Center. One finding about the color choice is the following:

The results of this preliminary evaluation were reported and there was a general consensus that the "white on blue" markers could be more distinguishable and could serve to supplement the standard milepost marker which has traditionally been "white on green" in conformance with concept that the information presented serves as guide sign-type information.

[hbelkins]

KTC -- a branch of the University of Kentucky College of Engineering. Not to be confused with KYTC, the Kentucky Transportation Cabinet.

[epzik8]

So is there no MUTCD standard color for these?

[SkyPesos]

So is there no MUTCD standard color for these?

Nope, states can pick between blue or green, although a bunch of the blue enhanced mile markers states (namely IN, KY and OH I can think of so far) have some one-off green ones.

I can see where the reasoning for using blue comes from. You use enhanced mile markers to give out your location on a freeway to roadside assistance or a 911 dispatcher in an emergency, which is a service, and normally denoted in blue on freeways. As said above in the thread, they aren't used for navigation (which is what green signs are for).