Most important interstate that isn't x0/x5

[bing101]

The Future I-7 or I-9 aka CA-99 because of agriculture traffic   in the San Joaquin valley.


Also the future I-11 in the Las Vegas area due to Vegas Traffic.

[hotdogPi]

The Future I-7 or I-9 aka CA-99 because of agriculture traffic   in the San Joaquin valley.


Also the future I-11 in the Las Vegas area due to Vegas Traffic.

If they're more important than 44, 64, 81, 94, etc., then how come those exist, while I-7, I-9, and I-11 don't? Wouldn't the more important ones be a higher priority for creation?

[ColossalBlocks]

The Future I-7 or I-9 aka CA-99 because of agriculture traffic   in the San Joaquin valley.


Also the future I-11 in the Las Vegas area due to Vegas Traffic.

If they're more important than 44, 64, 81, 94, etc., then how come those exist, while I-7, I-9, and I-11 don't? Wouldn't the more important ones be a higher priority for creation?

Probably funding. You'd have to worry about building an Interstate and maintaining all the existing roads under your jurisdiction.

[sparker]

The Future I-7 or I-9 aka CA-99 because of Truck Traffic due to agriculture goods in the San Joaquin valley.


Also the future I-11 in the Las Vegas area due to Vegas Traffic.

If one looks as the commercial traffic data for CA 99 it clearly indicates that it's carrying more of that category of traffic than most segments of the Interstate system.  While that alone technically qualifies it for consideration as a system addition, the fact that it was completed as a full freeway (regardless of I-standard compatibility) absent chargeable Interstate funding poses a "mixed bag" to both Caltrans and the backers of Interstate conversion.  On one hand, overall it's closer to Interstate standards than ever before -- since all the work done on the corridor since the end of the '60's has been to Interstate standard, but -- OTOH -- it's a fully functional freeway (albeit with deteriorating structure in some areas), and more or less a fait accompli to Caltrans (if not for local promoters of the upgrade concept).  Even though the corridor was declared a "future Interstate" within the HPC 54 language back in 2005, that elicits at best a shrug of the shoulders from Caltrans, who aren't about to lift a finger to shepherd that proposal through to fruition (despite the concurrent presence of their own "master plan" for CA 99 -- which actually exceeds Interstate standards).  Any further action will likely have to go back to the Congressional level for instigation -- and after 12 years of inaction, it may be a bit stale right now. 

As for I-11 -- if they can figure out just how to address Phoenix metro efficiently, that corridor/project stands a bit better chance of near-term success.

Neither corridor, however, stands a chance in hell -- even if & when fully completed -- at supplanting such worthies as 94, 44, or 81 in terms of national importance. 

[Revive 755]

If they're more important than 44, 64, 81, 94, etc., then how come those exist, while I-7, I-9, and I-11 don't? Wouldn't the more important ones be a higher priority for creation?

Probably funding. You'd have to worry about building an Interstate and maintaining all the existing roads under your jurisdiction.

I'd also add:

* It was easier to build interstates back when 44, 64, 81 and 94 were being planned.

* Some of the cities in question, such as Las Vegas, were not as populated back when the original interstate system was being laid out.  I'll speculate that had Las Vegas been more populated back in the 1940's and 1950's, I-17 may have been routed there instead of Flagstaff.  I'm not sure this holds for the CA 99 corridor though - looks like there was enough population along CA 99 that I-5 should have been built along it.

[Beltway]

Depends on what you mean by "important".   If you are talking about commerce, I-81 is right at the top.  If you are talking about tourists, then I-4.  If you are talking about the military, then I-64, connecting many major bases and reserve centers to the largest military center in the world, Norfolk, is.  If you are talking about public safety of a place likely to need evacutaion, I-26.

All those routes have multiple functions.  All except I-81 have important roles for hurricane evacuation.  All handle various levels of tourist traffic.  I-4 and I-26 serve major military bases.  All Interstates handle considerable commerce, albeit I-64 doesn't carry nearly the commercial traffic as does I-81.

One of the factors with I-94 that would lessen its relative national importance to some degree, is the fact that much of it especially in the Midwestern major city corridor of Madison to Detroit, is paralleled in close proximity by I-90 which provides urban relief/alternative in some areas (Chicago and NW Indiana) and an outer bypass/alternative in other areas (Chicago to Madison).

[Quillz]

If they're more important than 44, 64, 81, 94, etc., then how come those exist, while I-7, I-9, and I-11 don't? Wouldn't the more important ones be a higher priority for creation?

Probably funding. You'd have to worry about building an Interstate and maintaining all the existing roads under your jurisdiction.

I'd also add:

* It was easier to build interstates back when 44, 64, 81 and 94 were being planned.

* Some of the cities in question, such as Las Vegas, were not as populated back when the original interstate system was being laid out.  I'll speculate that had Las Vegas been more populated back in the 1940's and 1950's, I-17 may have been routed there instead of Flagstaff.  I'm not sure this holds for the CA 99 corridor though - looks like there was enough population along CA 99 that I-5 should have been built along it.

My understanding was I-5 was deliberately intended to be a long-haul bypass of the major Central Valley population centers. It was only later that the planners realized that maybe that was a mistake, or that there was certainly a case for two interstates.

[kkt]

If they're more important than 44, 64, 81, 94, etc., then how come those exist, while I-7, I-9, and I-11 don't? Wouldn't the more important ones be a higher priority for creation?

Probably funding. You'd have to worry about building an Interstate and maintaining all the existing roads under your jurisdiction.

I'd also add:

* It was easier to build interstates back when 44, 64, 81 and 94 were being planned.

* Some of the cities in question, such as Las Vegas, were not as populated back when the original interstate system was being laid out.  I'll speculate that had Las Vegas been more populated back in the 1940's and 1950's, I-17 may have been routed there instead of Flagstaff.  I'm not sure this holds for the CA 99 corridor though - looks like there was enough population along CA 99 that I-5 should have been built along it.

My understanding was I-5 was deliberately intended to be a long-haul bypass of the major Central Valley population centers. It was only later that the planners realized that maybe that was a mistake, or that there was certainly a case for two interstates.

Bypassing the population centers, and also large sections of substandard highway.  The thinking was, they'd build the west valley freeway, and it would serve as both a permanent better route for long distance traffic and a bypass route for 99 as they upgraded it bit by bit.

[Beltway]

I'm not sure this holds for the CA 99 corridor though - looks like there was enough population along CA 99 that I-5 should have been built along it.

My understanding was I-5 was deliberately intended to be a long-haul bypass of the major Central Valley population centers. It was only later that the planners realized that maybe that was a mistake, or that there was certainly a case for two interstates.

Bypassing the population centers, and also large sections of substandard highway.  The thinking was, they'd build the west valley freeway, and it would serve as both a permanent better route for long distance traffic and a bypass route for 99 as they upgraded it bit by bit.

Even today the I-5 "super bypass" goes thru areas of very little population that don't warrant an Interstate highway.

Why not route I-5 within a band of about 5 miles on either side of CA-99?  That way it would take advantage of being a new location highway with the most modern design standards, being a bypass of CA-99, and being in relative proximity to the populated areas along CA-99.

[sparker]

I'm not sure this holds for the CA 99 corridor though - looks like there was enough population along CA 99 that I-5 should have been built along it.

My understanding was I-5 was deliberately intended to be a long-haul bypass of the major Central Valley population centers. It was only later that the planners realized that maybe that was a mistake, or that there was certainly a case for two interstates.

Bypassing the population centers, and also large sections of substandard highway.  The thinking was, they'd build the west valley freeway, and it would serve as both a permanent better route for long distance traffic and a bypass route for 99 as they upgraded it bit by bit.

Even today the I-5 "super bypass" goes thru areas of very little population that don't warrant an Interstate highway.

Why not route I-5 within a band of about 5 miles on either side of CA-99?  That way it would take advantage of being a new location highway with the most modern design standards, being a bypass of CA-99, and being in relative proximity to the populated areas along CA-99.

That idea might be technically feasible in the more rural areas (generally from Delano north to Tulare), but the S.J. Valley towns have undergone quite a bit of expansion.  Eastward is generally out of the question no matter what; that is the principal direction of expansion for Tulare, the urbanized belt between Kingsburg and Madera (including Fresno), and all the "M" towns (Merced, Modesto, Manteca) north of there plus Turlock.  You'd run into housing in all those areas; any close-in alternative would have to wind around like a vine around a post to avoid taking a lot of housing or businesses.  However, while it may seem like something to the west would be easier pickings, much of that land is owned by major agribusinesses with attorneys at the ready. 

The possibility of Caltrans ever considering a 3rd parallel corridor (the near-dead CA 65 foothill route notwithstanding) in the Valley is slim, none, and both of the above.  Their projected "master" plan brings the entire route out to a minimum of 6 lanes, all along the present alignment (with miniscule variances to address some substandard lines of sight, particularly in Tulare County).  [For references, see the CA 99 thread in Southwest].  But the probability of that plan advancing beyond a spot project here and there to correct some of the more egregious sections (including some sub-15-foot overheads) in the near term is very low; the route is viewed within the agency as being, in an overall sense, adequate -- particularly now that there's zero cross traffic on 99 from its southern terminus to Sacramento.  It'll take concentrated political pressure from Valley politicos to change that situation -- and they seem to have had, at least in recent history, "bigger fish to fry" than CA 99. 

In the long run, CA 99 -- whether as an Interstate or not -- will be at least brought up to current geometric standards if not fully expanded to 6+ lanes.  But I certainly wouldn't hold my breath for any comprehensive corridor-length transformations in at least the next decade or two. 

[bing101]

I-66 because of Washington D.C. Traffic.

[kkt]

I'm not sure this holds for the CA 99 corridor though - looks like there was enough population along CA 99 that I-5 should have been built along it.

My understanding was I-5 was deliberately intended to be a long-haul bypass of the major Central Valley population centers. It was only later that the planners realized that maybe that was a mistake, or that there was certainly a case for two interstates.

Bypassing the population centers, and also large sections of substandard highway.  The thinking was, they'd build the west valley freeway, and it would serve as both a permanent better route for long distance traffic and a bypass route for 99 as they upgraded it bit by bit.

Even today the I-5 "super bypass" goes thru areas of very little population that don't warrant an Interstate highway.

Why not route I-5 within a band of about 5 miles on either side of CA-99?  That way it would take advantage of being a new location highway with the most modern design standards, being a bypass of CA-99, and being in relative proximity to the populated areas along CA-99.

Even the relatively large central valley towns are still small compared to the metropolises of the S.F. Bay Area and greater L.A.  I-5 is a shorter distance between them, so it would remain the preferred route for through traffic even in CA 99 were completely upgraded.

Six lanes is a pretty big reach for CA 99.  It would be a lot more cost effective to make CA 99 four lanes with geometric design appropriate for an interstate, and instead upgrade I-5 to six lanes.  Most of I-5 was designed with some growth space.

[mapman1071]

I - 19

[Beltway]

I'm not sure this holds for the CA 99 corridor though - looks like there was enough population along CA 99 that I-5 should have been built along it.

My understanding was I-5 was deliberately intended to be a long-haul bypass of the major Central Valley population centers. It was only later that the planners realized that maybe that was a mistake, or that there was certainly a case for two interstates.

Bypassing the population centers, and also large sections of substandard highway.  The thinking was, they'd build the west valley freeway, and it would serve as both a permanent better route for long distance traffic and a bypass route for 99 as they upgraded it bit by bit.

Even today the I-5 "super bypass" goes thru areas of very little population that don't warrant an Interstate highway.
Why not route I-5 within a band of about 5 miles on either side of CA-99?  That way it would take advantage of being a new location highway with the most modern design standards, being a bypass of CA-99, and being in relative proximity to the populated areas along CA-99.

That idea might be technically feasible in the more rural areas (generally from Delano north to Tulare), but the S.J. Valley towns have undergone quite a bit of expansion.  Eastward is generally out of the question no matter what; that is the principal direction of expansion for Tulare, the urbanized belt between Kingsburg and Madera (including Fresno), and all the "M" towns (Merced, Modesto, Manteca) north of there plus Turlock.  You'd run into housing in all those areas; any close-in alternative would have to wind around like a vine around a post to avoid taking a lot of housing or businesses.  However, while it may seem like something to the west would be easier pickings, much of that land is owned by major agribusinesses with attorneys at the ready. 

The possibility of Caltrans ever considering a 3rd parallel corridor (the near-dead CA 65 foothill route notwithstanding) in the Valley is slim, none, and both of the above.  Their projected "master" plan brings the entire route out to a minimum of 6 lanes, all along the present alignment (with miniscule variances to address some substandard lines of sight, particularly in Tulare County).  [For references, see the CA 99 thread in Southwest].  But the probability of that plan advancing beyond a spot project here and there to correct some of the more egregious sections (including some sub-15-foot overheads) in the near term is very low; the route is viewed within the agency as being, in an overall sense, adequate -- particularly now that there's zero cross traffic on 99 from its southern terminus to Sacramento.  It'll take concentrated political pressure from Valley politicos to change that situation -- and they seem to have had, at least in recent history, "bigger fish to fry" than CA 99. 

In the long run, CA 99 -- whether as an Interstate or not -- will be at least brought up to current geometric standards if not fully expanded to 6+ lanes.  But I certainly wouldn't hold my breath for any comprehensive corridor-length transformations in at least the next decade or two. 

My comments weren't about a -current- rerouting of I-5, it was about previous comments about the -original- location of I-5, as to the question of why wasn't it routed within a band of about 5 miles on either side of CA-99.

[Beltway]

Even today the I-5 "super bypass" goes thru areas of very little population that don't warrant an Interstate highway.
Why not route I-5 within a band of about 5 miles on either side of CA-99?  That way it would take advantage of being a new location highway with the most modern design standards, being a bypass of CA-99, and being in relative proximity to the populated areas along CA-99.

Even the relatively large central valley towns are still small compared to the metropolises of the S.F. Bay Area and greater L.A.  I-5 is a shorter distance between them, so it would remain the preferred route for through traffic even in CA 99 were completely upgraded.

Six lanes is a pretty big reach for CA 99.  It would be a lot more cost effective to make CA 99 four lanes with geometric design appropriate for an interstate, and instead upgrade I-5 to six lanes.  Most of I-5 was designed with some growth space.

Los Angeles to Sacramento is 386 miles via I-5 alone
Los Angeles to Sacramento is 388 miles via CA-99 north of Wheeler Ridge

[jwolfer]

Depends on what you mean by "important".   If you are talking about commerce, I-81 is right at the top.  If you are talking about tourists, then I-4.  If you are talking about the military, then I-64, connecting many major bases and reserve centers to the largest military center in the world, Norfolk, is.  If you are talking about public safety of a place likely to need evacutaion, I-26.

I agree i4 is important for tourism,  however i4 serves the 2nd and 3rd sized metro areas in the 3rd largest state in the country.

Much more than Disney in Florida

LGMS428

[Beltway]

Depends on what you mean by "important".   If you are talking about commerce, I-81 is right at the top.  If you are talking about tourists, then I-4.  If you are talking about the military, then I-64, connecting many major bases and reserve centers to the largest military center in the world, Norfolk, is.  If you are talking about public safety of a place likely to need evacutaion, I-26.

I agree i4 is important for tourism,  however i4 serves the 2nd and 3rd sized metro areas in the 3rd largest state in the country.
Much more than Disney in Florida

Military bases within the I-4 service area --

MacDill Air Force Base, approximately 7 miles south of Tampa.

Naval Air Warfare Center Training System Division, Florida (NAWCTSD) is located in Orlando.

[sparker]

I'm not sure this holds for the CA 99 corridor though - looks like there was enough population along CA 99 that I-5 should have been built along it.

My understanding was I-5 was deliberately intended to be a long-haul bypass of the major Central Valley population centers. It was only later that the planners realized that maybe that was a mistake, or that there was certainly a case for two interstates.

Bypassing the population centers, and also large sections of substandard highway.  The thinking was, they'd build the west valley freeway, and it would serve as both a permanent better route for long distance traffic and a bypass route for 99 as they upgraded it bit by bit.

Even today the I-5 "super bypass" goes thru areas of very little population that don't warrant an Interstate highway.
Why not route I-5 within a band of about 5 miles on either side of CA-99?  That way it would take advantage of being a new location highway with the most modern design standards, being a bypass of CA-99, and being in relative proximity to the populated areas along CA-99.

That idea might be technically feasible in the more rural areas (generally from Delano north to Tulare), but the S.J. Valley towns have undergone quite a bit of expansion.  Eastward is generally out of the question no matter what; that is the principal direction of expansion for Tulare, the urbanized belt between Kingsburg and Madera (including Fresno), and all the "M" towns (Merced, Modesto, Manteca) north of there plus Turlock.  You'd run into housing in all those areas; any close-in alternative would have to wind around like a vine around a post to avoid taking a lot of housing or businesses.  However, while it may seem like something to the west would be easier pickings, much of that land is owned by major agribusinesses with attorneys at the ready. 

The possibility of Caltrans ever considering a 3rd parallel corridor (the near-dead CA 65 foothill route notwithstanding) in the Valley is slim, none, and both of the above.  Their projected "master" plan brings the entire route out to a minimum of 6 lanes, all along the present alignment (with miniscule variances to address some substandard lines of sight, particularly in Tulare County).  [For references, see the CA 99 thread in Southwest].  But the probability of that plan advancing beyond a spot project here and there to correct some of the more egregious sections (including some sub-15-foot overheads) in the near term is very low; the route is viewed within the agency as being, in an overall sense, adequate -- particularly now that there's zero cross traffic on 99 from its southern terminus to Sacramento.  It'll take concentrated political pressure from Valley politicos to change that situation -- and they seem to have had, at least in recent history, "bigger fish to fry" than CA 99. 

In the long run, CA 99 -- whether as an Interstate or not -- will be at least brought up to current geometric standards if not fully expanded to 6+ lanes.  But I certainly wouldn't hold my breath for any comprehensive corridor-length transformations in at least the next decade or two. 

My comments weren't about a -current- rerouting of I-5, it was about previous comments about the -original- location of I-5, as to the question of why wasn't it routed within a band of about 5 miles on either side of CA-99.

Didn't realize your concept was retroactive to '57.  In either case, the Westside Freeway (as it was conceptually called in pre-Interstate days) had been a longstanding Division of Highways concept (since at least the immediate postwar time frame) as an efficient conduit between L.A. and the Bay Area.  US 99 through the major Valley cities & towns had been in a process of gradual upgrade since the late '30's, with full freeway sections through Galt, Manteca, Chowchilla, Tulare, and Delano fully deployed by the time the Interstate system was initiated in '56 (and the original Fresno freeway bypass was under construction as well).  The original concept was to simply route I-5 up US 99, expanding on what was already in place, and splitting into I-5E and I-5W in Modesto (the grading for the "split" interchange is still in place today!).  The Division of Highways saw the opportunity to get the direct LA-SF route built with 90% federal funds, so they petitioned to reroute I-5 over the Westside alignment, claiming that the projected AADT derived from interregional travel would at least offset that of the aggregate local and long-distance totals for the US 99 routing.  Despite the original stated Interstate system concept of connecting cities over 50K (and the 1955 census estimates showed both Bakersfield and Fresno exceeding that number), FHWA elected to relocate I-5 to the Westside alignment, much to the consternation of officials along the US 99 corridor.  The Division reassured these folks that even though the Interstate took the "beeline" metro-to-metro route to the west, they wouldn't be left out -- that US 99 would continue to be improved until it was itself a full freeway (which finally happened some 59 years later -- and 50 years after the U.S. shields were replaced!). 

To the Division of Highways, the I-5 location was a stark choice -- continue with what they were already doing along US 99, or take the most direct route possible -- where I-5 is today.  Although at that time there was sufficient land, mostly to the west of the 99 alignment, to deploy a route such as was suggested in the prior post, it would simply be a way to avoid a lot of in-town freeway mileage through the various Valley cities -- but still maintaining the basic 99 trajectory, laid out as it was along the original Southern Pacific rail line -- it wouldn't have "solved" the issue of the conception of I-5 as the aforementioned inter-metropolitan "beeline", but merely recasting the US 99 alignment to a new-terrain route a few miles away.  And that wasn't a choice even offered back in '57 -- it was 99 or the Westside -- period (this was 2 years prior to the conception of the omnibus California Freeway and Expressway system, which codified this and other statewide highway planning efforts).     

[Beltway]

My comments weren't about a -current- rerouting of I-5, it was about previous comments about the -original- location of I-5, as to the question of why wasn't it routed within a band of about 5 miles on either side of CA-99.

Didn't realize your concept was retroactive to '57.  In either case, the Westside Freeway (as it was conceptually called in pre-Interstate days) had been a longstanding Division of Highways concept (since at least the immediate postwar time frame) as an efficient conduit between L.A. and the Bay Area.  US 99 through the major Valley cities & towns had been in a process of gradual upgrade since the late '30's, with full freeway sections through Galt, Manteca, Chowchilla, Tulare, and Delano fully deployed by the time the Interstate system was initiated in '56 (and the original Fresno freeway bypass was under construction as well).  The original concept was to simply route I-5 up US 99, expanding on what was already in place, and splitting into I-5E and I-5W in Modesto (the grading for the "split" interchange is still in place today!).  The Division of Highways saw the opportunity to get the direct LA-SF route built with 90% federal funds, so they petitioned to reroute I-5 over the Westside alignment, claiming that the projected AADT derived from interregional travel would at least offset that of the aggregate local and long-distance totals for the US 99 routing.  Despite the original stated Interstate system concept of connecting cities over 50K (and the 1955 census estimates showed both Bakersfield and Fresno exceeding that number), FHWA elected to relocate I-5 to the Westside alignment, much to the consternation of officials along the US 99 corridor.  The Division reassured these folks that even though the Interstate took the "beeline" metro-to-metro route to the west, they wouldn't be left out -- that US 99 would continue to be improved until it was itself a full freeway (which finally happened some 59 years later -- and 50 years after the U.S. shields were replaced!). 

To the Division of Highways, the I-5 location was a stark choice -- continue with what they were already doing along US 99, or take the most direct route possible -- where I-5 is today.  Although at that time there was sufficient land, mostly to the west of the 99 alignment, to deploy a route such as was suggested in the prior post, it would simply be a way to avoid a lot of in-town freeway mileage through the various Valley cities -- but still maintaining the basic 99 trajectory, laid out as it was along the original Southern Pacific rail line -- it wouldn't have "solved" the issue of the conception of I-5 as the aforementioned inter-metropolitan "beeline", but merely recasting the US 99 alignment to a new-terrain route a few miles away.  And that wasn't a choice even offered back in '57 -- it was 99 or the Westside -- period (this was 2 years prior to the conception of the omnibus California Freeway and Expressway system, which codified this and other statewide highway planning efforts).     

Thanks for the detailed explanation, that is what I was looking for, as to how CalTrans made the decision in the late 1950s.

However, as I pointed out, the mileage savings is insignificant, 2 miles out of 388 miles.  I-5 between Wheeler Ridge and Tracy goes thru areas of very low population, even today.

I-5 between Tracy and Sacramento is more of the idea that I had in mind, a new location routing within about 6 to 8 miles away from CA-99 that is a bypass but also close enough to provide access to the CA-99 corridor.

I just don't see the logic for how Caltrans routed I-5 between Wheeler Ridge and Tracy.  The "Westside Freeway" concept from the 1940s just doesn't seem to have any advantages over the CA-99 corridor.

[MikeTheActuary]

https://ops.fhwa.dot.gov/freight/freight_analysis/nat_freight_stats/docs/08factsfigures/images/fig3_5.jpg

I'd put I-81 ahead of I-94.  While 94 might be longer and serve actual cities, 81 for much of its length is a major freight corridor.

[Tom958]

76. It was built first for good reason.

[sparker]

My comments weren't about a -current- rerouting of I-5, it was about previous comments about the -original- location of I-5, as to the question of why wasn't it routed within a band of about 5 miles on either side of CA-99.

Didn't realize your concept was retroactive to '57.  In either case, the Westside Freeway (as it was conceptually called in pre-Interstate days) had been a longstanding Division of Highways concept (since at least the immediate postwar time frame) as an efficient conduit between L.A. and the Bay Area.  US 99 through the major Valley cities & towns had been in a process of gradual upgrade since the late '30's, with full freeway sections through Galt, Manteca, Chowchilla, Tulare, and Delano fully deployed by the time the Interstate system was initiated in '56 (and the original Fresno freeway bypass was under construction as well).  The original concept was to simply route I-5 up US 99, expanding on what was already in place, and splitting into I-5E and I-5W in Modesto (the grading for the "split" interchange is still in place today!).  The Division of Highways saw the opportunity to get the direct LA-SF route built with 90% federal funds, so they petitioned to reroute I-5 over the Westside alignment, claiming that the projected AADT derived from interregional travel would at least offset that of the aggregate local and long-distance totals for the US 99 routing.  Despite the original stated Interstate system concept of connecting cities over 50K (and the 1955 census estimates showed both Bakersfield and Fresno exceeding that number), FHWA elected to relocate I-5 to the Westside alignment, much to the consternation of officials along the US 99 corridor.  The Division reassured these folks that even though the Interstate took the "beeline" metro-to-metro route to the west, they wouldn't be left out -- that US 99 would continue to be improved until it was itself a full freeway (which finally happened some 59 years later -- and 50 years after the U.S. shields were replaced!). 

To the Division of Highways, the I-5 location was a stark choice -- continue with what they were already doing along US 99, or take the most direct route possible -- where I-5 is today.  Although at that time there was sufficient land, mostly to the west of the 99 alignment, to deploy a route such as was suggested in the prior post, it would simply be a way to avoid a lot of in-town freeway mileage through the various Valley cities -- but still maintaining the basic 99 trajectory, laid out as it was along the original Southern Pacific rail line -- it wouldn't have "solved" the issue of the conception of I-5 as the aforementioned inter-metropolitan "beeline", but merely recasting the US 99 alignment to a new-terrain route a few miles away.  And that wasn't a choice even offered back in '57 -- it was 99 or the Westside -- period (this was 2 years prior to the conception of the omnibus California Freeway and Expressway system, which codified this and other statewide highway planning efforts).     

Thanks for the detailed explanation, that is what I was looking for, as to how CalTrans made the decision in the late 1950s.

However, as I pointed out, the mileage savings is insignificant, 2 miles out of 388 miles.  I-5 between Wheeler Ridge and Tracy goes thru areas of very low population, even today.

I-5 between Tracy and Sacramento is more of the idea that I had in mind, a new location routing within about 6 to 8 miles away from CA-99 that is a bypass but also close enough to provide access to the CA-99 corridor.

I just don't see the logic for how Caltrans routed I-5 between Wheeler Ridge and Tracy.  The "Westside Freeway" concept from the 1940s just doesn't seem to have any advantages over the CA-99 corridor.

Yeah -- it's ironic that as a LA-Sacramento route, there's scant mileage difference between the full I-5 route and the I-5/CA 99 alternative via Bakersfield and Fresno.  However, it does cut off several miles from the L.A. to San Francisco "inland" route (as opposed to US 101), which was nominally a combination of US 99, CA 120, and US 50.  In that context it must be noted that the original I-5 concept included service to and from the Bay Area (via the "split" of I-5W and I-5E); the selection of the Westside alignment was intended to emphasize that particular priority.  The decision to jettison the E/W designations in 1963 -- 17 years prior to AASHTO's policy change re suffixed Interstates -- was more due to the fact that this would have required a nearly 50-mile multiplex of I-80 and I-5W only a few miles from the west I-80 terminus; that was considered a bit awkward -- and happened at the same time that the Division of Highways was formulating plans to eliminate in-state multiplexes in general (as expressed in the next year's mass renumbering).  The elimination of both the suffixed routes and the long Interstate multiplex was simply the "first shot across the bow" of that entire process.

[Max Rockatansky]

My comments weren't about a -current- rerouting of I-5, it was about previous comments about the -original- location of I-5, as to the question of why wasn't it routed within a band of about 5 miles on either side of CA-99.

Didn't realize your concept was retroactive to '57.  In either case, the Westside Freeway (as it was conceptually called in pre-Interstate days) had been a longstanding Division of Highways concept (since at least the immediate postwar time frame) as an efficient conduit between L.A. and the Bay Area.  US 99 through the major Valley cities & towns had been in a process of gradual upgrade since the late '30's, with full freeway sections through Galt, Manteca, Chowchilla, Tulare, and Delano fully deployed by the time the Interstate system was initiated in '56 (and the original Fresno freeway bypass was under construction as well).  The original concept was to simply route I-5 up US 99, expanding on what was already in place, and splitting into I-5E and I-5W in Modesto (the grading for the "split" interchange is still in place today!).  The Division of Highways saw the opportunity to get the direct LA-SF route built with 90% federal funds, so they petitioned to reroute I-5 over the Westside alignment, claiming that the projected AADT derived from interregional travel would at least offset that of the aggregate local and long-distance totals for the US 99 routing.  Despite the original stated Interstate system concept of connecting cities over 50K (and the 1955 census estimates showed both Bakersfield and Fresno exceeding that number), FHWA elected to relocate I-5 to the Westside alignment, much to the consternation of officials along the US 99 corridor.  The Division reassured these folks that even though the Interstate took the "beeline" metro-to-metro route to the west, they wouldn't be left out -- that US 99 would continue to be improved until it was itself a full freeway (which finally happened some 59 years later -- and 50 years after the U.S. shields were replaced!). 

To the Division of Highways, the I-5 location was a stark choice -- continue with what they were already doing along US 99, or take the most direct route possible -- where I-5 is today.  Although at that time there was sufficient land, mostly to the west of the 99 alignment, to deploy a route such as was suggested in the prior post, it would simply be a way to avoid a lot of in-town freeway mileage through the various Valley cities -- but still maintaining the basic 99 trajectory, laid out as it was along the original Southern Pacific rail line -- it wouldn't have "solved" the issue of the conception of I-5 as the aforementioned inter-metropolitan "beeline", but merely recasting the US 99 alignment to a new-terrain route a few miles away.  And that wasn't a choice even offered back in '57 -- it was 99 or the Westside -- period (this was 2 years prior to the conception of the omnibus California Freeway and Expressway system, which codified this and other statewide highway planning efforts).     

Thanks for the detailed explanation, that is what I was looking for, as to how CalTrans made the decision in the late 1950s.

However, as I pointed out, the mileage savings is insignificant, 2 miles out of 388 miles.  I-5 between Wheeler Ridge and Tracy goes thru areas of very low population, even today.

I-5 between Tracy and Sacramento is more of the idea that I had in mind, a new location routing within about 6 to 8 miles away from CA-99 that is a bypass but also close enough to provide access to the CA-99 corridor.

I just don't see the logic for how Caltrans routed I-5 between Wheeler Ridge and Tracy.  The "Westside Freeway" concept from the 1940s just doesn't seem to have any advantages over the CA-99 corridor.

Yeah -- it's ironic that as a LA-Sacramento route, there's scant mileage difference between the full I-5 route and the I-5/CA 99 alternative via Bakersfield and Fresno.  However, it does cut off several miles from the L.A. to San Francisco "inland" route (as opposed to US 101), which was nominally a combination of US 99, CA 120, and US 50.  In that context it must be noted that the original I-5 concept included service to and from the Bay Area (via the "split" of I-5W and I-5E); the selection of the Westside alignment was intended to emphasize that particular priority.  The decision to jettison the E/W designations in 1963 -- 17 years prior to AASHTO's policy change re suffixed Interstates -- was more due to the fact that this would have required a nearly 50-mile multiplex of I-80 and I-5W only a few miles from the west I-80 terminus; that was considered a bit awkward -- and happened at the same time that the Division of Highways was formulating plans to eliminate in-state multiplexes in general (as expressed in the next year's mass renumbering).  The elimination of both the suffixed routes and the long Interstate multiplex was simply the "first shot across the bow" of that entire process.

Interesting to think how much more awful the 99 corridor would be if I-5 used it in the Central Valley and all you had was 33 as the quasi alternate.  I-5 really does get a ton of truck/commuter off 99 already and its still congested as all hell.  I couldn't fathom how many lanes it would take to handle the traffic of both 99 and I-5 in the Central Valley today onto one route.....maybe 8 from Bakersfield to Fresno?

[20160805]

My first thought was I-94. Then I checked kurumi's list.

http://kurumi.com/roads/rank2di.html

Which confirms what you (and I) thought.

Judging by that list, 94 is even more important than the major 35, 15, 55, 20, 65, 85, 25, and especially 30.

[Beltway]

Thanks for the detailed explanation, that is what I was looking for, as to how CalTrans made the decision in the late 1950s.
However, as I pointed out, the mileage savings is insignificant, 2 miles out of 388 miles.  I-5 between Wheeler Ridge and Tracy goes thru areas of very low population, even today.
I-5 between Tracy and Sacramento is more of the idea that I had in mind, a new location routing within about 6 to 8 miles away from CA-99 that is a bypass but also close enough to provide access to the CA-99 corridor.
I just don't see the logic for how Caltrans routed I-5 between Wheeler Ridge and Tracy.  The "Westside Freeway" concept from the 1940s just doesn't seem to have any advantages over the CA-99 corridor.

Yeah -- it's ironic that as a LA-Sacramento route, there's scant mileage difference between the full I-5 route and the I-5/CA 99 alternative via Bakersfield and Fresno.  However, it does cut off several miles from the L.A. to San Francisco "inland" route (as opposed to US 101), which was nominally a combination of US 99, CA 120, and US 50.  In that context it must be noted that the original I-5 concept included service to and from the Bay Area (via the "split" of I-5W and I-5E); the selection of the Westside alignment was intended to emphasize that particular priority.  The decision to jettison the E/W designations in 1963 -- 17 years prior to AASHTO's policy change re suffixed Interstates -- was more due to the fact that this would have required a nearly 50-mile multiplex of I-80 and I-5W only a few miles from the west I-80 terminus; that was considered a bit awkward -- and happened at the same time that the Division of Highways was formulating plans to eliminate in-state multiplexes in general (as expressed in the next year's mass renumbering).  The elimination of both the suffixed routes and the long Interstate multiplex was simply the "first shot across the bow" of that entire process.

The I-580 connection to I-5 might have needed to be moved 8 or 10 miles to the west, but the overall distance difference would have been insignificant.  Maybe 10 miles longer than the current 383 miles between LA and SF.