Total miles of highways that include suffix branches?

[Lyon Wonder]

In calculating total miles of individual Interstates and US highways that also have routes with suffix E and W or even alternate A routes on US highways, do all of a highway's suffix routes also count in the total mileage? 

Of course the only interstate that still has suffix routes is I-35, which is 1,568 miles long from Laredo, TX to Duluth, and is split into I-35W and I-35E in both Dallas-Forth Worth, TX and Minneapolis-St Paul, MN.   I guess the official total miles of I-35 also includes both the I-35E and I-35W routes, even though someone driving I-35 straight from Laredo to Duluth or vis a versa would likely only drive on one of the suffix routes in TX and MN. 

And several US highways have suffix and alternate routes too, such as US-31 and US-41 in KY and TN.

[NE2]

There's no answer to your question because it depends on the purpose you want the mileage for.

[Big John]

Of course the only interstate that still has suffix routes is I-35,

Did you miss the suffixes they just put on I-69 in Texas?

[wxfree]

There is no single answer to your question.  It depends on whether you're asking about official mileage, driving mileage, shortest alternate mileage, or what.

I can address I-35 in Texas.  Officially, I-35 runs from Laredo to Hillsboro, and from Denton to the Red River.  The official route and mileage exclude 35W and 35E.  I-35E continues the mile marker and exit numbers of I-35, while I-35W has its own set of numbers.  The mile numbers north of Denton show the mileage from Laredo if you count along I-35E.  I-35W is a slightly shorter distance.

The only way to know the answer to your question is to know exactly what the question is.

[KEVIN_224]

Does the split of the eastern and western spurs of I-95 in northern NJ count in this case?

[NE2]

Does the split of the eastern and western spurs of I-95 in northern NJ count in this case?

In what case?

[Alps]

The needed context isn't "for what purpose," it's "by what standard?" Are we talking about AASHTO/FHWA consideration of route length, or as reported by state DOTs?

[Duke87]

The most basic question here from a utilitarian standpoint is "If I drive this highway from end to end, how many miles is it?". In which case you would include the mileage of one but not both branches wherever it splits. Which one is up to the driver. Or, to have a more constant standard, use whichever branch is shorter.

Does the split of the eastern and western spurs of I-95 in northern NJ count in this case?

That is an odd case because unlike with 35 and now 69, there is no I-95E and I-95W there. New Jersey considers the eastern spur to be I-95 and the western spur to be I-95W. FHWA considers the western spur to be I-95 and has no designation for the eastern spur.

From the perspective of the driver, though, it is effectively the same as 35 and 69: a place where the road goes two different ways and the driver must arbitrarily pick one as the through route.

[NE2]

FHWA considers the western spur to be I-95 and has no designation for the eastern spur.

[citation needed]

[Alps]

FHWA considers the western spur to be I-95 and has no designation for the eastern spur.

[citation needed]

[fact]

[NE2]

FHWA considers the western spur to be I-95 and has no designation for the eastern spur.

[citation needed]

[fact]

http://en.wikipedia.org/wiki/Template:Fact

[kphoger]

Lyon Wonder, are you ever going to post again in the thread you started?

[Duke87]

FHWA considers the western spur to be I-95 and has no designation for the eastern spur.

[citation needed]

[fact]

This does get me curious, though. I have heard from several people that FHWA considers the western spur to be 95, but is there a document anywhere (publicly available or otherwise) that confirms this? FHWA's website has mileages but says nothing about alignments. Interestingly, said website lists 95 in New Jersey as 97.76 miles, which is about right for both spurs, plus the Trenton segment.

[hbelkins]

This wouldn't be an issue with US 70, which maintains its own identity despite having two suffixed branches, or US 9, which keeps its identity while spawning US 9W.

Or even, I guess, with US 6 since US 6N is a spur route.

[Alps]

FHWA considers the western spur to be I-95 and has no designation for the eastern spur.

[citation needed]

[fact]

This does get me curious, though. I have heard from several people that FHWA considers the western spur to be 95, but is there a document anywhere (publicly available or otherwise) that confirms this? FHWA's website has mileages but says nothing about alignments. Interestingly, said website lists 95 in New Jersey as 97.76 miles, which is about right for both spurs, plus the Trenton segment.

Both spurs are part of the Interstate system, that much I do know. As for which one is the "mainline," I suspect that will come down to if they ever force the Turnpike to go mileage-based, at which point you'll find I-95 signed on the Westerly.