Interstate 81 in Syracuse

[roadman65]

Google Street View has the north interchange shown with the abutments to the flyover built.  The image dated 11 months ago.

So it seems fitting by now it would be done.

[Rothman]

Drove over the new flyover today.  Pretty spiffy.

[vdeane]

With the new imagery on Google Street View, I took a look to confirm the milemarkers on I-81 north of Syracuse, and it's... interesting.  Everything from Sandy Creek north is as I'd expect, but heading south from there, it appears to get further and further off from what one would calculate from doing math on the existing mile markers.  It's to the point where I don't know how it will be reconciled along existing I-481, because at that point, everything is 0.5-0.6 miles off, depending on whether you calculate from MP 82 to the south (the last mile marker before existing and new I-81 diverge) and MP 103 (the last one posted on the new set, since Onondaga County hasn't been done yet).  For my exit list, I'm going to measure from the south for existing I-481 and from the north for the remainder of I-81 in Onondaga County, but that leaves some weirdness around exit 96.

That said, the new mile markers are more accurate than the old ones, but unless they're redoing everything to the south, or setting them closer together than they actually are along I-481, it's going to leave a jump somewhere.  The old milemarkers got ahead of themselves in northern Broome County and Cortland County (still do) and then let the actual mileage catch up in Oswego County, so this is just reflective of counting down accurate mileage from the north rather than the south.  This also means that the original mile-based exit numbers for exits 63 and 67 (62 and 66, respectively) were likely right, they just needed to move all the milemarkers.

This will certainly make for an interesting site update this weekend.  Maybe I'll need to do an actual/posted split for I-81 like I do for I-86/NY 17, but that feels like a decision for after when they finish all of them.

[The Ghostbuster]

Are there still any exit numbers on Interstate 81 that have not been converted to mileage-based? Google Maps still shows Interstate 81 having sequential numbers from old Exit 38 northward to the Canadian border.

[cu2010]

None of the exits in Jefferson County have been converted, R7 is taking their dear old time and the home office seems unable to just force them to actually do it.

The exits in Syracuse proper (future BR81) are even more of a dysfunctional confusing mess. When I was there two weeks ago, the conversion was in process...the exits for Syracuse Airport had both the old and new numbers simultaneously!

[vdeane]

With the new imagery on Google Street View, I took a look to confirm the milemarkers on I-81 north of Syracuse, and it's... interesting.  Everything from Sandy Creek north is as I'd expect, but heading south from there, it appears to get further and further off from what one would calculate from doing math on the existing mile markers.  It's to the point where I don't know how it will be reconciled along existing I-481, because at that point, everything is 0.5-0.6 miles off, depending on whether you calculate from MP 82 to the south (the last mile marker before existing and new I-81 diverge) and MP 103 (the last one posted on the new set, since Onondaga County hasn't been done yet).  For my exit list, I'm going to measure from the south for existing I-481 and from the north for the remainder of I-81 in Onondaga County, but that leaves some weirdness around exit 96.

That said, the new mile markers are more accurate than the old ones, but unless they're redoing everything to the south, or setting them closer together than they actually are along I-481, it's going to leave a jump somewhere.  The old milemarkers got ahead of themselves in northern Broome County and Cortland County (still do) and then let the actual mileage catch up in Oswego County, so this is just reflective of counting down accurate mileage from the north rather than the south.  This also means that the original mile-based exit numbers for exits 63 and 67 (62 and 66, respectively) were likely right, they just needed to move all the milemarkers.

This will certainly make for an interesting site update this weekend.  Maybe I'll need to do an actual/posted split for I-81 like I do for I-86/NY 17, but that feels like a decision for after when they finish all of them.

Upon more measuring, I have come to the conclusion that this is indeed the case.  After thinking about it, I plan to do an actual/posted split for Cortland and Onondaga Counties (or at least as far north as NY 481) and revise as necessary once new milemarkers are posted between exits 81 and 102.

[Jim]

It's too bad no other states have ever done a successful conversion to mile-based exit numbers, otherwise New York might have had some examples to follow.

[vdeane]

After thinking about it, I plan to do an actual/posted split for Cortland and Onondaga Counties (or at least as far north as NY 481) and revise as necessary once new milemarkers are posted between exits 81 and 102.

Turns out it's possible to avoid a hard jump by using actual numbering counting down from the north along existing I-481 and being careful with mile figures around the southern interchange.  As such, there is no actual/posted split, though I've kept all the figures for both future and historical I-81 pending the actual posting of milemarkers on I-481 just in case.  Given how this lines up with the exit numbers, I suspect that I won't have to end up changing it much.

[kramie13]

It's too bad no other states have ever done a successful conversion to mile-based exit numbers, otherwise New York might have had some examples to follow.

Massachusetts converted their entire state in under a year (between Oct. 2020 and Aug. 2021).  How was that NOT successful?

[Rothman]

It's too bad no other states have ever done a successful conversion to mile-based exit numbers, otherwise New York might have had some examples to follow.

Massachusetts converted their entire state in under a year (between Oct. 2020 and Aug. 2021).  How was that NOT successful?

There are so many layers to how this response to Jim's post is amusing.

[roadman65]

Saw the control cities on I-481 started changing. A picture showing Binghamton on a SB I-481 pull through was submitted to Freeway Jim on FB recently.

Don't know if that was a mistake made by a poster assuming it's been started as I imagine Binghamton must be used South of Dewitt already.

Basically I'm asking the question. Has it started yet?