I-17 & 19 in Arizona

[golden eagle]

Since both highways are short in length, and their termini are a little over 100 miles apart, wouldn't it have been logical to have I-17 duplex with I-10 from Phoenix to Tucson and then have I-17 separate where the current I-19 stands? Or could there actually be plans to extend both roads?

[Molandfreak]

19 would be the number for taking over both and 17 should replace proposed 11.

No official extensions are planned.  Doing so would be a huge waste of money.

And then there's the road enthusiast fantasy of I-17 being extended to Saint George.  No further south.

[swbrotha100]

It might have been something to consider back in the 1960s to have one number from Nogales to Flagstaff. However, there are no official plans today for ADOT to do that.

If you do a search of "I-17 Phoenix to Salt Lake City" there are various links that mention extending I-17 north of Flagstaff, but not only are there no official plans for that, it would seem the future I-11 to I-15 would cover most of that route. Realistically, maybe there could be upgrades to US 89, but the terrain of northern Arizona makes it unlikely there will ever be a new interstate highway there.

[NE2]

Northeast from Flagstaff to the Four Corners area and then north-northwest to Salt Lake is more reasonable terrain-wise. But it's barely shorter than via Las Vegas.

What's needed is a "signature" bridge across the Grand Canyon.

[myosh_tino]

What's needed is a "signature" bridge across the Grand Canyon.

Just make sure Caltrans isn't in charge of building it otherwise it will be over budget, have brittle bolts, corroded steel tendons and open later than expected. 

Note: I realize the bridge NE2 is talking about wouldn't be in California but when I hear the term "Signature Span" all I can think of is the new S.F. Oakland Bay Bridge which is slowly turning into a "fustercluck".

[Rover_0]

And then there's the road enthusiast fantasy of I-17 being extended to Saint George.  No further south.

Yep, that one's my preferred route should I-17 ever get extended north from Flagstaff.

It might have been something to consider back in the 1960s to have one number from Nogales to Flagstaff. However, there are no official plans today for ADOT to do that.

If you do a search of "I-17 Phoenix to Salt Lake City" there are various links that mention extending I-17 north of Flagstaff, but not only are there no official plans for that, it would seem the future I-11 to I-15 would cover most of that route. Realistically, maybe there could be upgrades to US 89, but the terrain of northern Arizona makes it unlikely there will ever be a new interstate highway there.

I was searching the internets and found that ADOT has talked about four-laning US-89 up to US-160 dating to 2008. Another one dates to 2006.

An I-17 extension to I-15 near St. George would be a feat, but it's not exactly impossible. From Flagstaff to Page* and St. George to about Kanab-ish**, the terrain is relatively flat and doesn't pose many obstacles. Between Kanab and Page is where the most issues arise--a road cut would need to be widened, an additional pair of lanes would need to be built just to the east of that, and then you'd need a new 4-lane bridge across the Colorado.

While I'd love to see I-17 enter southern Utah with a "minimal" build plan^, I can only see I-17 reaching Page and/or an I-x15 spur running east from I-15 near St. George to--at the very longest--the Kanab/Fredonia area in the foreseeable future. If you could convince FHWA to once again allow super-two Interstates, you could conceivably extend I-17 to I-15 near St. George with a skeletal build, but I'm not holding my breath. Then again, stranger things have happened.

I wonder if/how the US-89 landslide south of Page has had any affect on any US-89 widening, if at all.

*Using N-20 from The Gap northward. Building over sand shouldn't bother ADOT much, as US-89 north of Kanab is built across a sandy area and hasn't had any issues as far as I (or family from the area) can remember.

**You do have the Hurricane Cliffs (or Hill, as the case may be), but UDOT and citizens have discussed a bypass that could connect UT-7 (Southern Parkway) and UT-59 east of Hurricane that, if built to 4 lanes and expressway-grade, could take care of that obstacle.

^Mainly using the US-89/89A/AZ-389/UT-59 route as one pair of lanes where it doesn't enter into a populated area, using the narrowest possible standards (Jersey barrier) through the more difficult terrain, and so forth. Only bypasses would need to be built around major towns, and I've heard some rumblings out of Kanab discussing such a bypass, though I don't know how serious they are.

[Alps]

Since this isn't Fictional Highways... I wonder if this was done because I-17 was built first and numbered over a different highway than 19, or if Arizona somehow got away with something they shouldn't have.

[NE2]

Both routes were part of the planned system since the 1940s. It's worth noting that the I-17 split was at Wickenburg (and the I-8 split at Phoenix) on the 1957 map that first showed numbers, despite both being moved to their present locations by 1955.

It'd also make a pretty long overlap; the only longer one in 1957 was 80/90, which can be justified by wanting both routes to serve both coasts. However, 20/59, which is similar in topology and geometry to 17/19, is longer with the split moved from Wickenburg. (But why weren't 59 and 81 combined?)

[Brandon]

Since this isn't Fictional Highways... I wonder if this was done because I-17 was built first and numbered over a different highway than 19, or if Arizona somehow got away with something they shouldn't have.

I thought both routes were replacements for US-89.  It is a good question as to why Arizona got both I-17 and I-19 when one number might have been viable.  I don't know all of the politics of the early Interstate System all that well.

[agentsteel53]

However, 20/59, which is similar in topology and geometry to 17/19, is longer with the split moved from Wickenburg.

it's interesting to consider the length of the overlap as a proportion of the length of the individual routes.  17/19 would be multiplexed with 10 for ~35% of its length.  59 is multiplexed with 20 for ~33% of its length.  very similar. 

apparently, "333 miles, 1/3 of which is multiplexed" was not enough, while "444 miles, 1/3 of which is multiplexed" was.

or maybe Arizona, like Texas and Illinois, argued for many little interstates, each with their own number.

[Henry]

19 would be the number for taking over both and 17 should replace proposed 11.

No official extensions are planned.  Doing so would be a huge waste of money.

And then there's the road enthusiast fantasy of I-17 being extended to Saint George.  No further south.

This I agree with!

However, 20/59, which is similar in topology and geometry to 17/19, is longer with the split moved from Wickenburg.

it's interesting to consider the length of the overlap as a proportion of the length of the individual routes.  17/19 would be multiplexed with 10 for ~35% of its length.  59 is multiplexed with 20 for ~33% of its length.  very similar. 

apparently, "333 miles, 1/3 of which is multiplexed" was not enough, while "444 miles, 1/3 of which is multiplexed" was.

or maybe Arizona, like Texas and Illinois, argued for many little interstates, each with their own number.

Either way, the grid there is screwed up anyway, especially when you take into account the fact that I-11 as currently proposed would be entirely east of I-15.

[Rover_0]

19 would be the number for taking over both and 17 should replace proposed 11.

No official extensions are planned.  Doing so would be a huge waste of money.

And then there's the road enthusiast fantasy of I-17 being extended to Saint George.  No further south.

This I agree with!

What, I-19 being extended and replacing current I-17, or I-17 being extended northwest to St. George?

[swbrotha100]

Since this isn't Fictional Highways... I wonder if this was done because I-17 was built first and numbered over a different highway than 19, or if Arizona somehow got away with something they shouldn't have.

I thought both routes were replacements for US-89.  It is a good question as to why Arizona got both I-17 and I-19 when one number might have been viable.  I don't know all of the politics of the early Interstate System all that well.

I-19 directly replaced US 89 between Nogales and Tucson. The southern section of I-17 directly replaced AZ 69 between Phoenix and Cordes Junction (where current AZ 69 begins headed to Prescott). The northern section of I-17 replaced an original alignment of AZ 79.

http://www.arizonaroads.com/interstate/i17.html

http://www.arizonaroads.com/interstate/i19.html

[NE2]

But on the map where the I-17 designation was first assigned it was a direct replacement of US 89 from Wickenburg to Ash Fork.

[Molandfreak]

But on the map where the I-17 designation was first assigned it was a direct replacement of US 89 from Wickenburg to Ash Fork.

Really? If that would have happened, I could see why 89's decommissioning was necessary. But as-is, I just don't see why (89 or 89A is still the fastest way to Prescott no matter how you slice the cake)

[NE2]

Really. Read my post earlier in this thread about how the proposed Interstate was already on the current corridor but the planners fucked up and used an old map for assigning numbers. This has nothing to do with the truncation of US 89 more than 30 years later.

[Molandfreak]

Really. Read my post earlier in this thread about how the proposed Interstate was already on the current corridor but the planners fucked up and used an old map for assigning numbers. This has nothing to do with the truncation of US 89 more than 30 years later.

I see it now. Then I-17 would be a lot shorter.

[Speedway99]

And then there's the road enthusiast fantasy of I-17 being extended to Saint George.  No further south.

Yep, that one's my preferred route should I-17 ever get extended north from Flagstaff.

It might have been something to consider back in the 1960s to have one number from Nogales to Flagstaff. However, there are no official plans today for ADOT to do that.

If you do a search of "I-17 Phoenix to Salt Lake City" there are various links that mention extending I-17 north of Flagstaff, but not only are there no official plans for that, it would seem the future I-11 to I-15 would cover most of that route. Realistically, maybe there could be upgrades to US 89, but the terrain of northern Arizona makes it unlikely there will ever be a new interstate highway there.

I was searching the internets and found that ADOT has talked about four-laning US-89 up to US-160 dating to 2008. Another one dates to 2006.

An I-17 extension to I-15 near St. George would be a feat, but it's not exactly impossible. From Flagstaff to Page* and St. George to about Kanab-ish**, the terrain is relatively flat and doesn't pose many obstacles. Between Kanab and Page is where the most issues arise--a road cut would need to be widened, an additional pair of lanes would need to be built just to the east of that, and then you'd need a new 4-lane bridge across the Colorado.

While I'd love to see I-17 enter southern Utah with a "minimal" build plan^, I can only see I-17 reaching Page and/or an I-x15 spur running east from I-15 near St. George to--at the very longest--the Kanab/Fredonia area in the foreseeable future. If you could convince FHWA to once again allow super-two Interstates, you could conceivably extend I-17 to I-15 near St. George with a skeletal build, but I'm not holding my breath. Then again, stranger things have

I wonder if/how the US-89 landslide south of Page has had any affect on any US-89 widening, if at all.

*Using N-20 from The Gap northward. Building over sand shouldn't bother ADOT much, as US-89 north of Kanab is built across a sandy area and hasn't had any issues as far as I (or family from the area) can remember.

**You do have the Hurricane Cliffs (or Hill, as the case may be), but UDOT and citizens have discussed a bypass that could connect UT-7 (Southern Parkway) and UT-59 east of Hurricane that, if built to 4 lanes and expressway-grade, could take care of that obstacle.

^Mainly using the US-89/89A/AZ-389/UT-59 route as one pair of lanes where it doesn't enter into a populated area, using the narrowest possible standards (Jersey barrier) through the more difficult terrain, and so forth. Only bypasses would need to be built around major towns, and I've heard some rumblings out of Kanab discussing such a bypass, though I don't know how serious they are.

I like the idea of I-17 being extended to near Spanish Fork, then paralleling I-15 through Provo and Salt Lake City. In Salt Lake City, the two can overlap until Tremonton, where I-17 takes over I-84 until the junction with I-86. I-84 then goes to Pocatello. Current I-84 east of Ogden becomes I-480.

[NE2]

I don't.

[Molandfreak]

I like the idea of I-17 being extended to near Spanish Fork, then paralleling I-15 through Provo and Salt Lake City. In Salt Lake City, the two can overlap until Tremonton, where I-17 takes over I-84 until the junction with I-86. I-84 then goes to Pocatello. Current I-84 east of Ogden becomes I-480.

What? Where did this come from? Why on earth would there be a need for two parallel interstates in Utah?

[agentsteel53]

What? Where did this come from? Why on earth would there be a need for two parallel interstates in Utah?

make one a toll road to better reflect how things are done in Florida and New Jersey.

[Speedway99]

What? Where did this come from? Why on earth would there be a need for two parallel interstates in Utah?

make one a toll road to better reflect how things are done in Florida and New Jersey.

Exactly, that's what I was thinking. The toll road can be a reliever, I got the idea from FL and NJ. Also prevents a long overlap (Though yo do have the I-80/90 tollway overlap in OH and IN). I wanted to fix the eastern I-86 problem, while giving SLC proper a 3rd 2di. I think that's a good idea.

[Rover_0]

What? Where did this come from? Why on earth would there be a need for two parallel interstates in Utah?

make one a toll road to better reflect how things are done in Florida and New Jersey.

Exactly, that's what I was thinking. The toll road can be a reliever, I got the idea from FL and NJ. Also prevents a long overlap (Though yo do have the I-80/90 tollway overlap in OH and IN). I wanted to fix the eastern I-86 problem, while giving SLC proper a 3rd 2di. I think that's a good idea.

I've never thought of that one before; it makes sense and gives an interesting take on the "Renumbering I-84 southeast of I-86" idea. But, as is the case for extending I-17 to I-15 somewhere in St. George, I'm not sure if the costs for a Wasatch Front toll road and the Tuba City/Crescent Junction route would be worth it.

One possible advantage for an eventual (or even partial*) I-17 extension to St. George as opposed to Spanish Fork is that the St. George route could be used as an I-11 reliever of sorts, especially if significant/important portions of I-11 are tolled. But, I can see US-6 between Green River and Spanish Fork eventually getting upgraded (even if only partially).

*I.E., I-17 extended north to Page and/or a St. George/Kanab spur, with US-89 as-is (or thereabouts) connecting the sections.

[Henry]

19 would be the number for taking over both and 17 should replace proposed 11.

No official extensions are planned.  Doing so would be a huge waste of money.

And then there's the road enthusiast fantasy of I-17 being extended to Saint George.  No further south.

This I agree with!

What, I-19 being extended and replacing current I-17, or I-17 being extended northwest to St. George?

Well, to clear things up, I'd suggest routing I-17 over proposed I-11; as for I-19, I'd route it over what is now I-17 and extend it northwest to St. George.

[Quillz]

I made a map once that combined I-17/I-19 and also took it all the way north to Reno via US-95. I kept the "17," despite the obvious numbering violation west of Vegas. I also turned the majority of what presently exists as I-17 into a 3di, something like I-117.

I would agree I-17/I-19 probably should be one Interstate, but it will never happen. Not at this point, anyway. Perhaps in a perfect world, the long-proposed "Vegas to Phoenix" could have been combined with a potential "Phoenix to Nogales" to make a much longer single unifying Interstate, but oh well.