AZ: US 89 south terminus in Flagstaff

[US 89]

TM currently has the US 89 south end at its junction with BL-40/US 180 at Country Club Drive. While this is where the End sign is located, there is a legitimate argument to move it west to the junction with old US 66. The signage for westbound 66 at that intersection, including both the shields and street blade, suggests US 89 begins to the east there.

But perhaps the strongest argument for moving it would be the AZDOT route log. It doesn't explicitly state the location of the terminus because the portion in city limits appears to be locally maintained, but it does give the Townsend-Winona Road intersection as milepost 2.37, which puts milepost 0.00 exactly at the Historic 66 intersection.

[neroute2]

How does this compare to the 2005 log? https://azdot.gov/sites/default/files/2019/05/2005shslog.pdf
I'm on my phone so I can't do a detailed comparison.

[US 89]

The 2005 log does include the mileposts less than 1.79, and it states that that segment was transferred to the city of Flagstaff in January 2005. The zero milepost is listed as "Begin U 089 at SB040(4)", and there is a point at MP 0.32 that reads "(EB) SB040(4) NB(on)", which reads to me like there's a brief concurrency with Business 40 before that splits off back to I-40. Mileages outside Flagstaff are the same in both the 2005 and 2013 logs.

Interestingly that 0.32-mile figure is a little bit off from what I'm measuring on Google Maps, but a detailed mileage analysis there is difficult because that junction has been significantly reconfigured since the 2005 route log was made - it was reconfigured from a full trumpet to a standard intersection in 2007.

[neroute2]

I bet mile 0 is southwest of the intersection because that's where the trumpet ramps used to begin/end. Not because old US 66 is there.

[US 89]

Found an ArcGIS milepost map: http://www.arcgis.com/home/webmap/viewer.html?url=https%3A%2F%2Fgis.azgeo.az.gov%2Farcgis%2Frest%2Fservices%2FAdot%2FMileposts%2FMapServer&source=sd

It's not easy to navigate, but there is a milepost exactly at the Historic 66 intersection, which is named "M419.50 (Beg Seg N Flag CL)" on route "U 089RETIRED 1". It appears to be the southernmost US 89 milepost, and from what I can tell, the word "retired" just means the state doesn't maintain it anymore - there are some retired mileposts on BL-40 as well.

I bet mile 0 is southwest of the intersection because that's where the trumpet ramps used to begin/end. Not because old US 66 is there.

I considered that, but the N-to-W trumpet ramp ended slightly west of the 66 intersection, while the E-to-S ramp was a bit east. It still wouldn't explain the exact distance I get with the Google Maps distance tool.

[Duke87]

I suppose this is my problem to resolve since I took on AZ.

I agree with neroute2 that the mileposting likely zeroes back to where it does on account of where the trumpet ramps used to end, not on account of where the intersection with ex-US 66 is.

Key here is that US 66 was decommissioned in 1985 while US 89 was not truncated to Flagstaff until 1992. So for 89 to have an endpoint at former 66 would be anachronistic. Meanwhile the now-removed trumpet was in place well before 1992, so its presence would have been relevant, and it would have been logical to put mile 0 for US 89 where the US 180 mainline diverged at the time.


My inclination is to leave the endpoint of US 89 at US 180/BL I-40 where it is, but I'll leave the floor open for further discussion before I close this out.

[compdude787]

I'd say to leave this the way it is, I personally prefer that we go with what's on the ground over what some state highway log says. Otherwise someone might get to this intersection, see the END US 89 sign and think they've gotten to the end of US 89 and then take a left to head south towards I-40, when in reality they had not gotten to the southern terminus. I can imagine that it would be frustrating to come back from a roadtrip (especially if someone lives far away from Arizona like I do) only to realize that Travel Mapping has a different southern terminus than what was shown on the sign.

[Duke87]

Looks like 3-1 leave as is with no further comments submitted. Closing out.