Exit numbers on beltways - clockwise vs. counterclockwise

[akotchi]

That said, a sudden change from counting up to counting down for mileage (putting it another way, where the max mileage from both states meet at one point), does that have precedent, when crossing the state line?

Just in the last two years, when I-95 became I-295 in Pennsylvania and New Jersey, mileposts and exit numbers increase in both directions of I-295 toward the state line (Delaware River).  Of course, the cardinal directions also change at the state line, which makes this happen.  Pa-bound, for instance, increases to 76 (as North), then decreases from 10 (as West).

I did not think there were too many cases like this.

[vdeane]

See above. Again, you're sort of making my point. Certainly we know various highway departments will ignore MUTCD guidance when the guidance doesn't make sense. For example, on the Beltway in Virginia, VDOT signs the straight-thru movement on the Inner Loop (where I-95 splits off and heads south) as an "exit," even though you're staying on the same highway, because they say that's what the MUTCD requires because you have to "exit" I-95 onto I-495. Halfway around the Beltway from there, however, Maryland does not sign the equivalent thru movement on the Outer Loop (where I-95 splits off and heads north) as an "exit" even though the situation is essentially the same. I personally think Maryland's way of doing it makes more sense because it seems to me most motorists will view the road as "the Beltway" regardless of route number (though for years when the eastern Beltway was posted solely as I-95 and the western Beltway was solely I-495, people kept saying that was "confusing").

You could say Maryland is prioritizing I-495's numbers over I-95's in that case, seeing as they're otherwise the same on the Maryland side.

[CardInLex]

Out if curiosity, I looked to see if there are any rules mentioned in the MUTCD about this. Couldn't find language that specified what to do... but the sample diagram does show that you start at the southernmost point and proceed clockwise.

Correction: after further reading the MUTCD does specify this as the way to do it. However, as others have pointed out there are countless examples where this rule is not followed.

[SeriesE]

Out if curiosity, I looked to see if there are any rules mentioned in the MUTCD about this. Couldn't find language that specified what to do... but the sample diagram does show that you start at the southernmost point and proceed clockwise.

As with everything else, it's subject to exceptions. In the case of the Capital Beltway, for example, the standard convention is trumped by I-95 running along the eastern half of the Beltway, which is why Maryland numbered their portion anticlockwise (I-95 mileposts from the state line up to where I-95 leaves the Beltway to head north to Baltimore, and then continuing that numbering around the rest of the Beltway). Virginia had separate exit numbers for a good 20 years or so, but some people apparently found it confusing and eventually Virginia decided to continue Maryland's numbering with the exception of the seven-mile segment of Virginia's Beltway that's used by I-95.

In other words, if a 2di shares pavement with a 3di, the theory is that the 2di's numbering would trump the 3di's because the 2di is the "primary" route, even when the result is something that's likely to be illogical to the average motorist who has never heard of the MUTCD (such as Virginia's Beltway abruptly jumping from Exit 57 to Exit 173 within three miles). Of course, it's also fair to recognize that a local driver who uses the road on a regular basis should know about the inconsistency and be used to it, but I never underestimate the ignorance of the average motorist based on some of the letters I saw in the Washington Post's "Dr. Gridlock" column over the years.

I stand corrected. Didn't know MUTCD requires it clockwise from the southernmost point!

[ethanhopkin14]

I-610 around Houston and I-410 around San Antonio both increase counter-clockwise.

Um, they increase clockwise.  zero for I-410 at the southern intersection at I-35, running clockwise the intersection with I-10 is Exit 16

I-610 zero mile post is at SH-288 running clockwise the turn at Post Oak Rd. is at mile 4

[sprjus4]

I-610 around Houston and I-410 around San Antonio both increase counter-clockwise.

Um, they increase clockwise.  zero for I-410 at the southern intersection at I-35, running clockwise the intersection with I-10 is Exit 16

I-610 zero mile post is at SH-288 running clockwise the turn at Post Oak Rd. is at mile 4

For some reason, I had thought otherwise. You are correct.

[Super Mateo]

I-80/294 uses I-294's Mileage and Exits.

Which becomes a really bizarre decision when:
a.  I-80/94 uses I-80's Mileage east of there, resetting after 2 miles going east into Indiana and neither Interstate uses I-80's mileage after they split going west (meaning Torrence is exit 161, but no matter which way you go, the next exit number is much lower)
b.  I-294 terminates at the east end of the segment
c.  I-80 mile markers are used on both sides of it
d.  I-80 runs in the natural direction of the concurrency

[cwf1701]

And in Knoxville, I-75 uses I-640 miles and exits between I-75/I-275 and I-40.

[ilpt4u]

I-80/294 uses I-294's Mileage and Exits.

Which becomes a really bizarre decision when:
a.  I-80/94 uses I-80's Mileage east of there, resetting after 2 miles going east into Indiana and neither Interstate uses I-80's mileage after they split going west (meaning Torrence is exit 161, but no matter which way you go, the next exit number is much lower)
b.  I-294 terminates at the east end of the segment
c.  I-80 mile markers are used on both sides of it
d.  I-80 runs in the natural direction of the concurrency

Agreed. When the Tollway added exit numbers and redid the Tri-State MMs anyway, bringing the I-94 section into statewide I-94 mileage, the Southbound I-294 mileage should either "Zero"  at the I-80/294 interchange, or keep "Zero"  at the 80/94/294/394 interchange, but the SB I-80 exit should be the last exit with 294's numbering scheme, and the E-W multiplexed 80/294 section should use 80's MMs and exit numbers

It was important to unify I-94's exit numbers and MMs across the state/with IDOT, but somehow not I-80's. There is a logical flaw for how that thought process played out

[US 89]

The Athens Perimeter (GA 10 Loop) used to number in a clockwise direction but for some reason was changed to counterclockwise in 2004. Numbering starts at the US 29/US 78/GA 316 interchange at the southwest end.

[roadman65]

Out if curiosity, I looked to see if there are any rules mentioned in the MUTCD about this. Couldn't find language that specified what to do... but the sample diagram does show that you start at the southernmost point and proceed clockwise.

As with everything else, it's subject to exceptions. In the case of the Capital Beltway, for example, the standard convention is trumped by I-95 running along the eastern half of the Beltway, which is why Maryland numbered their portion anticlockwise (I-95 mileposts from the state line up to where I-95 leaves the Beltway to head north to Baltimore, and then continuing that numbering around the rest of the Beltway). Virginia had separate exit numbers for a good 20 years or so, but some people apparently found it confusing and eventually Virginia decided to continue Maryland's numbering with the exception of the seven-mile segment of Virginia's Beltway that's used by I-95.

In other words, if a 2di shares pavement with a 3di, the theory is that the 2di's numbering would trump the 3di's because the 2di is the "primary" route, even when the result is something that's likely to be illogical to the average motorist who has never heard of the MUTCD (such as Virginia's Beltway abruptly jumping from Exit 57 to Exit 173 within three miles). Of course, it's also fair to recognize that a local driver who uses the road on a regular basis should know about the inconsistency and be used to it, but I never underestimate the ignorance of the average motorist based on some of the letters I saw in the Washington Post's "Dr. Gridlock" column over the years.

I-465 in Indiana does not give way to I-74 (nor will it to I-69 when finished) in mileage markers or exit numbers. In fact, while I-74 is clearly signed during its concurrency with I-465, I've never once in my life heard anybody refer to the road as 74, either along or in conjunction with 465. Everybody just calls it 465. If you polled people who regularly drive on that section of 465, I'd guess that at least half don't even realize that the road is also 74.

You're sort of making my point for me. I said "the theory" is that the 2di should trump, but I don't think most people out on the road view it that way.

In other words, if a 2di shares pavement with a 3di, the theory is that the 2di's numbering would trump the 3di's because the 2di is the "primary" route, even when the result is something that's likely to be illogical to the average motorist who has never heard of the MUTCD

Some Midwest 3di's challenge your notion about this theory that that 2di's numbering trumps the 3di's when multiplexed

I-80/294 uses I-294's Mileage and Exits. I-74/465 uses I-465's Mileage and Exits. I-41/43/894 uses I-894's Mileage and Exits. I-94/694 uses I-494/694's Mileage and Exits

I-74/275 does have I-74's Mileage and Exits take over the Cincy Beltway Mileage for the short multiplex segment, as a case supporting your theory

See above. Again, you're sort of making my point. Certainly we know various highway departments will ignore MUTCD guidance when the guidance doesn't make sense. For example, on the Beltway in Virginia, VDOT signs the straight-thru movement on the Inner Loop (where I-95 splits off and heads south) as an "exit," even though you're staying on the same highway, because they say that's what the MUTCD requires because you have to "exit" I-95 onto I-495. Halfway around the Beltway from there, however, Maryland does not sign the equivalent thru movement on the Outer Loop (where I-95 splits off and heads north) as an "exit" even though the situation is essentially the same. I personally think Maryland's way of doing it makes more sense because it seems to me most motorists will view the road as "the Beltway" regardless of route number (though for years when the eastern Beltway was posted solely as I-95 and the western Beltway was solely I-495, people kept saying that was "confusing").

Not in Minnesota as I-94 gives up its exit numbers for the combination I-694 and I-494 which retain a full circle of exit numbers.  There is no Trumping here lol!

[Gnutella]

The Athens Perimeter (GA 10 Loop) used to number in a clockwise direction but for some reason was changed to counterclockwise in 2004. Numbering starts at the US 29/US 78/GA 316 interchange at the southwest end.

I was about to mention the Athens Perimeter. The interchanges were unnumbered until 2000, after which they were numbered clockwise by affixing new sign-width tabs on top of the existing signs (including some older button-copy signs). Then, when GDOT replaced all the signs in 2004, the interchanges were renumbered counterclockwise. Weird.

I hope the Perimeter gets the new-style GDOT signs soon. There's already two on the "outer" (counterclockwise) Perimeter at the Milledge Avenue interchange. A new gantry with the new signs was installed about two years ago, finally replacing the old gantry that magically disappeared about 10 years ago.

[mapman1071]

Both Az Loop 101 and Loop 202 Counterclockwise
Loop 303 ?