Most important interstate that isn't x0/x5

[vdeane]

I-94 should have been the northernmost x0 (so I-90), but you know, that whole problem of having to dodge the US Highways in the middle of the country.  The answer is I-94 thread over lol

If I-50 and I-60 were allowed, I would expect that I-94 would have been I-90 (and, likewise, I-90 west of Chicago would have been I-80 and east of Chicago would have been I-70; I-80 would have been I-60 and I-70 I-50).

[Beltway]

Try to access past copies of California Highways & Public Works, the Division of Highways "house organ" journal published from the 1920's through the beginning of 1967 (and one of the first things cut by the incoming Reagan gubernatorial administration).  Multiple articles regarding the selection of the alignment of the Westside Freeway and how it related to the (often) adjacent California Aqueduct project.  Since publication ceased during the time period that I-5 was being constructed, the articles related to the construction project itself are limited; most of what saw print dealt with the preliminary planning phases and the first segments to be opened (those north of CA 152).  But good reading for anyone interested in the whole process.

Looks like they have been online since 2013 ... perhaps you could find the articles.
http://www.americanroads.us/forum/index.php?topic=249.0

I have found two articles so far, they add value although they don't go to the original details of planning.  These issues --
Sept. - Oct. 1960
Sept. - Oct. 1962

[sparker]

I much agree with all those design criteria up to the last sentence.  Move the water toward the populated areas with as much natural flow as possible, reduce the need for pumping facilities as much as possible; IOW water does need to go "uphill" at certain points to clear higher areas, but reduce total elevation changes as much as possible.

However the routing of I-5 is no more directly related to that of the aqueduct system than the routing of CA-99 is directly related to that of the aqueduct system.

That last sentence referring to the proximity of the aqueduct to I-5 wasn't meant to suggest any form of project coordination -- except, of course, to ensure avoidance of any conflict between the two.  Any construction-related efficiencies, particularly in regards to projects utilizing the same general contractor, were likely ad hoc in nature rather than in accordance with some inter-agency "master plan".  The plain fact is that they are very close to one another along much of the northern stretches of each facility: I-5 is where it is (a) to shorten the overall L.A.-Bay Area mileage, all while (b) staying out of the valuable farmlands on the valley floor as much as possible; the aqueduct is where it is because (a) of the location of the original source, and (b) it's the shortest route to the San Luis reservoir complex.  It is a narrow stretch of land that both projects had available, so any overall project "coordination" probably involved just staying out of each others' way (unless they had to borrow a backhoe or something from the other project!). 

But seriously -- have fun reading CH & PW -- I started poring through the articles when I was about 9 years old (the local library shelved the journal).  It answers a lot of questions regarding CA highway history (and, ironically, about what was planned but later either deleted or shelved!). 

[Beltway]

I much agree with all those design criteria up to the last sentence.  Move the water toward the populated areas with as much natural flow as possible, reduce the need for pumping facilities as much as possible; IOW water does need to go "uphill" at certain points to clear higher areas, but reduce total elevation changes as much as possible.
However the routing of I-5 is no more directly related to that of the aqueduct system than the routing of CA-99 is directly related to that of the aqueduct system.

That last sentence referring to the proximity of the aqueduct to I-5 wasn't meant to suggest any form of project coordination -- except, of course, to ensure avoidance of any conflict between the two.  Any construction-related efficiencies, particularly in regards to projects utilizing the same general contractor, were likely ad hoc in nature rather than in accordance with some inter-agency "master plan".  The plain fact is that they are very close to one another along much of the northern stretches of each facility: I-5 is where it is (a) to shorten the overall L.A.-Bay Area mileage, all while (b) staying out of the valuable farmlands on the valley floor as much as possible; the aqueduct is where it is because (a) of the location of the original source, and (b) it's the shortest route to the San Luis reservoir complex.  It is a narrow stretch of land that both projects had available, so any overall project "coordination" probably involved just staying out of each others' way (unless they had to borrow a backhoe or something from the other project!). 

As I pointed out the distance savings LA-SF is only 5%.  The Central Valley is a vast area, and Interstate highways all over the country were routed thru farmlands.  As far as routing, I can see on Google Maps Satellite View that in few places the aqueduct and highway are in immediate proximity, in most places they are several miles or more apart. 

One article did point out that there were many places where the highway design and construction needed large amounts of borrow excavation material (that obtained outside of the highway's right-of-way) to sufficiently raise the highway grade above flat terrain so that the highway will drain properly, and that material could be obtained from the canal construction several miles away. 

Borrow excavation typically costs twice as much per cubic yard as does regular excavation (that moved within the highway's right-of-way), because the obtaining of borrow pits usually have to be negotiated between the contractor and a private landowner.  If the borrow material is in another public works project a few miles away that needs to have large amounts of material removed and disposed of somewhere else, that would considerably reduce the cost of it, both for the highway project and for the canal project.

[sparker]

I much agree with all those design criteria up to the last sentence.  Move the water toward the populated areas with as much natural flow as possible, reduce the need for pumping facilities as much as possible; IOW water does need to go "uphill" at certain points to clear higher areas, but reduce total elevation changes as much as possible.
However the routing of I-5 is no more directly related to that of the aqueduct system than the routing of CA-99 is directly related to that of the aqueduct system.

That last sentence referring to the proximity of the aqueduct to I-5 wasn't meant to suggest any form of project coordination -- except, of course, to ensure avoidance of any conflict between the two.  Any construction-related efficiencies, particularly in regards to projects utilizing the same general contractor, were likely ad hoc in nature rather than in accordance with some inter-agency "master plan".  The plain fact is that they are very close to one another along much of the northern stretches of each facility: I-5 is where it is (a) to shorten the overall L.A.-Bay Area mileage, all while (b) staying out of the valuable farmlands on the valley floor as much as possible; the aqueduct is where it is because (a) of the location of the original source, and (b) it's the shortest route to the San Luis reservoir complex.  It is a narrow stretch of land that both projects had available, so any overall project "coordination" probably involved just staying out of each others' way (unless they had to borrow a backhoe or something from the other project!). 

As I pointed out the distance savings LA-SF is only 5%.  The Central Valley is a vast area, and Interstate highways all over the country were routed thru farmlands.  As far as routing, I can see on Google Maps Satellite View that in few places the aqueduct and highway are in immediate proximity, in most places they are several miles or more apart. 

One article did point out that there were many places where the highway design and construction needed large amounts of borrow excavation material (that obtained outside of the highway's right-of-way) to sufficiently raise the highway grade above flat terrain so that the highway will drain properly, and that material could be obtained from the canal construction several miles away. 

Borrow excavation typically costs twice as much per cubic yard as does regular excavation (that moved within the highway's right-of-way), because the obtaining of borrow pits usually have to be negotiated between the contractor and a private landowner.  If the borrow material is in another public works project a few miles away that needs to have large amounts of material removed and disposed of somewhere else, that would considerably reduce the cost of it, both for the highway project and for the canal project.

That's a more than reasonable assumption; and almost certainly one that was utilized back in the early '60's during construction of the initial phases of both parallel projects.  In the process of skirting the fall line of the hills to the west, there was a lot of "cut and fill" across the various drainages on I-5 as well as I-580, and much of the material removed from the cuts was deemed substandard for fill purposes (more rubble than dirt, according to my cousin, who was on the Division inspection team for that phase of the Westside project); the material removed from the somewhat downslope location of the aqueduct canal was deemed better suited for that usage (would pack down better).   

[Beltway]

As I pointed out the distance savings LA-SF is only 5%.  The Central Valley is a vast area, and Interstate highways all over the country were routed thru farmlands.  As far as routing, I can see on Google Maps Satellite View that in few places the aqueduct and highway are in immediate proximity, in most places they are several miles or more apart. 
One article did point out that there were many places where the highway design and construction needed large amounts of borrow excavation material (that obtained outside of the highway's right-of-way) to sufficiently raise the highway grade above flat terrain so that the highway will drain properly, and that material could be obtained from the canal construction several miles away. 
Borrow excavation typically costs twice as much per cubic yard as does regular excavation (that moved within the highway's right-of-way), because the obtaining of borrow pits usually have to be negotiated between the contractor and a private landowner.  If the borrow material is in another public works project a few miles away that needs to have large amounts of material removed and disposed of somewhere else, that would considerably reduce the cost of it, both for the highway project and for the canal project.

That's a more than reasonable assumption; and almost certainly one that was utilized back in the early '60's during construction of the initial phases of both parallel projects.  In the process of skirting the fall line of the hills to the west, there was a lot of "cut and fill" across the various drainages on I-5 as well as I-580, and much of the material removed from the cuts was deemed substandard for fill purposes (more rubble than dirt, according to my cousin, who was on the Division inspection team for that phase of the Westside project); the material removed from the somewhat downslope location of the aqueduct canal was deemed better suited for that usage (would pack down better).   

Not sure how 'rubble' is defined there, but rocks and stones and pebbles are not in and of themselves a problem, but there are certain types of soil that make a solid highway subgrade, and there are other soils that do not have the needed load bearing capacity.  Most any highway right-of-way corridor will have both types and it is the job of the designers and construction engineers to ensure that only the right types are utilized.

Highly organic soils and topsoil are unsuitable and are removed and disposed of or saved for other uses where topsoil is needed.

Here is a good overview --

"Many different types of soils may be suitable for use in the construction of an embankment or fill, ranging from granular soils (sand and gravel), which are highly desirable, to the more finely sized soils (silt and clay), which are usually somewhat less desirable. Certain types of soils (such as saturated clays and highly organic soils) are considered unsuitable for use as materials in embankment or fill construction. Regardless of the type(s) of soil(s) used to construct embankments or fills, the material should be well graded, capable of being well compacted, be within a proper range of moisture to optimize compaction, and be free of unsuitable or deleterious materials, such as tree roots, branches, stumps, sludge, metal, or trash."

https://www.fhwa.dot.gov/publications/research/infrastructure/structures/97148/app4.cfm
....

In cut sections it is still necessary to have enough depth of suitable material, and in some areas undercut excavation is needed to remove unsuitable material, which is then backfilled with material that has been deemed suitable.

[Bickendan]

I-94 should have been the northernmost x0 (so I-90), but you know, that whole problem of having to dodge the US Highways in the middle of the country.  The answer is I-94 thread over lol

If I-50 and I-60 were allowed, I would expect that I-94 would have been I-90 (and, likewise, I-90 west of Chicago would have been I-80 and east of Chicago would have been I-70; I-80 would have been I-60 and I-70 I-50).

Certainly could have solved the issue of I-82 being north of I-84 after I-80N was renumbered.

[sparker]

I-94 should have been the northernmost x0 (so I-90), but you know, that whole problem of having to dodge the US Highways in the middle of the country.  The answer is I-94 thread over lol

If I-50 and I-60 were allowed, I would expect that I-94 would have been I-90 (and, likewise, I-90 west of Chicago would have been I-80 and east of Chicago would have been I-70; I-80 would have been I-60 and I-70 I-50).

Certainly could have solved the issue of I-82 being north of I-84 after I-80N was renumbered.

It would have been informative -- not to mention fun -- to have been the proverbial "fly on the wall" during the initial numbering scheme determination process back circa '56-'57 -- especially when feedback from the state DOT's came into play!  With all the long suffixed routes and convoluted alignments to slide the more northerly cross-country major routes around the Great Lakes -- and still keep the more vocal political types in the various states and metro areas reasonably happy -- I'll venture the numbering scheme went through several more iterations that the ones periodically forwarded and published.  For instance, the first system draft appeared to show that what was to become I-90 across the southern tier of Minnesota actually dipped down to follow IA 9 before dipping down even further at the east end of the state to cross into Wisconsin somewhere around Prairie du Chien before following US 18 east through Madison all the way to Milwaukee (shadowing current I-94 between the two cities).  Unless they "elbowed" the routes at Madison, it's unclear how those routes would have been numbered; my guess is 90 would have stayed on the Twin Cities route and the uninterrupted Buffalo, WY - Milwaukee route would have been 84 or 86 (if the former, the New England iteration of 84 might have been 86!).  94 would have been confined to a cross-Michigan role, likely in the same capacity as the original 92/94 plan for that state ca. 1957.  Trying to please everyone while staying at or close to Eisenhower's 40/41K limitations likely would prove a daunting if not harrowing task!   

[bing101]

I-h1, I-h2, I-h201. All interstates in Hawaii.

[Beltway]

I-h1, I-h2, I-h201. All interstates in Hawaii.

I just read where Oahu is building an $8 billion light rail line.  This is enough to make you feel like blowing upchuck.

"A contentious special session of the Hawaii Legislature has averted the latest crisis for Honolulu's controversial light-rail project, enacting a $2.4-billion financial bridge that backers hope will carry construction of the planned 20-mile, $8-billion system to completion in 2025. Already six years behind schedule, the state's largest public-works effort still faces an uncertain future."

http://www.enr.com/articles/42730-funding-boost-shores-up-troubled-honolulu-rail-project

[achilles765]

I know this is now a nearly 5 year old thread, but I found it in a search recently and wanted to weigh in/possibly revive it...

To me, I-81, I-84 (west), I-94, and I would maybe add I-59 (as an extension of I-81) as currently almost as important as an x0 or x5 route...
However, once I-69 is complete from Mexico to Canada, I think it will surpass all the others...and even be more deserving of an x5 than I-45 or I-85. 

Fictional territory here, but that is why I would honestly prefer IH 69 to be renumbered IH 45 and our current IH 45 can be IH 47

[SkyPesos]

I know this is now a nearly 5 year old thread, but I found it in a search recently and wanted to weigh in/possibly revive it...

To me, I-81, I-84 (west), I-94, and I would maybe add I-59 (as an extension of I-81) as currently almost as important as an x0 or x5 route...
However, once I-69 is complete from Mexico to Canada, I think it will surpass all the others...and even be more deserving of an x5 than I-45 or I-85. 

Fictional territory here, but that is why I would honestly prefer IH 69 to be renumbered IH 45 and our current IH 45 can be IH 47

I tried to find the length of a completed I-69 a while ago. Counting a completed I-69 with it's longest branch (69E), it'll beat I-94 as the longest non x0 or x5 interstate, also beating all the x5 except I-75 and I-95 in length. If all the branches are counted, it'll be longer than I-75, but still fall a bit short below I-95.

[MATraveler128]

I think that I-71 is a rather important route. It connects the three largest cities in Ohio and is also a good way to switch cross country routes. For example, driving from Boston to Los Angeles can be shaved off significantly. It might be north south, but it almost functions as an east west route. And we can't forget about I-44. It's a lengthy east west route that connects St Louis and Wichita Falls. South of OKC, it's sort of questionable, but it was part of old Route 66, so that makes it even more important.