CA 15 not around anymore?

[Max Rockatansky]

If it makes everyone feel better Caltrans does sign I-710 in two segments which actually aren't FHWA defined Interstate. 

[kkt]

I think the Interstate shield means something to the trucking community, where that shield should provide some guaranteee of minimum bridge heights, curve radii, grades, etc. It might signify something similar for general drivers. This is why the numbering-oddity I-238 exists: to show truckers (at the time it was numbered) that I-238 was an acceptable truck route, so that they didn't take I-580 through Oakland, which couldn't handle trucks. But again, in these days, with NavApps, that's less critical. Truckers have specialized trucking NavApps that direct them along the right routes.

If they wanted to do that, then perhaps it would have been better for I-580 to follow I-238 and the remainder of I-580 to instead be CA 238 (or some other state route number).

Sigh.

See https://www.cahighways.org/itypes-history.html . I-580 is chargeable insterstate, assigned by AASHTO way back in 1945 (it replaced what would have been I-5W). It was later extended from a terminus with I-80 in Oakland across the bay to end at US 101.

I-238, although once submitted to be chargeable, is non-chargeable interstate approved in May 1983.

If one was somehow to do what you propose, you now have this long duplex of I-580 and I-880 (which is also non-chargeable interstate, approved with I-238) to I-80. That wouldn't fly too well because of the funding rules.

In short: I-238 is a case of "get over it". It's a numbering oddity, and won't be fixed.

But why should it even be allowed to be an interstate if trucks are prohibited?

Well, because, FHA approved it

Carrying trucks is ONE purpose of interstates, but not the only one.  The S.F. Bay Area is blessed with many other truck routes.

I-580 is built to the same standards as other interstates, and trucks have been allowed during temporary periods when there has been major damage to the I-880 freeway route, most obviously the Loma Prieta Earthquake aftermath in which I-880 structure collapsed.

[cahwyguy]

The key there is "temporary". As I note on my page, there is legislation prohibiting trucks in the stretch through Oakland:

Trucks are banned along the stretch of I-580 that runs along the base of the East Bay Hills in Oakland and San Leandro. The truck ban on I-580 dates back to 1951, before the road was even a highway. Then it was called MacArthur Boulevard and Oakland's City Council wanted to keep it free from truck traffic. MacArthurs Blvd traverses the Oakland hills, which were middle and upper middle class, and the flatlands (which were traversed by US 101E/Route 17 (now I-880) were working class. When MacArthur Boulevard became a highway in the early 1960s, the City of Oakland continued the ban on a roughly nine mile stretch of highway without significant debate. It applied to vehicles weighing more than 9,000 pounds, like big rigs, but not smaller trucks like those delivering packages on residential streets. The ban also excluded buses. In 1967, the ban was up for renewal, this time sparking a more intense deliberation. The possibility that trucks could barrel down both East Bay highways made people irate. The California Department of Transportation, Caltrans, studied the issue in 1967 to verify that trucks could travel an alternate route instead of I-580. The study looked at traffic, not impacts on health or quality of life. According to their website, the department concluded that "there was no strong evidence either to retain or to terminate the truck ban." Caltrans recommended the ban be extended indefinitely, but with periodic reviews of "operations of the alternate routes, 238 and 880." Those reviews happened just a few times, with none occurring after 1972.
(Source: KQED, 7/1/2021)

In 1990, the California Trucking Association asked Caltrans to study lifting the ban on trucks on I-580. And according to their  website, Caltrans officials said if they found good reasons to lift the ban – and the City of Oakland was onboard – they would recommend opening the freeway to trucks. That study never happened though. Residents living along I-580 worried studying the issue would open the door to lifting the ban, so they put pressure on their representatives to stop the study before it started. The Oakland City Council passed a resolution affirming they wanted to continue the ban. State legislators also wanted to stop the study and continue the ban. The Assemblyperson at the time said her constituents felt that if Oakland and San Leandro lifted the ban, they would be breaking a promise made to residents decades ago. The I-580 highway ban is the only one of its kind meant to assuage the concerns of local residents. According to the Federal Highway Authority, there are only nine such bans nationwide. Seven of those bans are due to construction or structural engineering constraints. One ban – on the Theodore Roosevelt Memorial Bridge in D.C. – was ordered by President Eisenhower to keep trucks away from the Lincoln Memorial.
(Source: KQED, 7/1/2021)

So, designating Route 238 as I-238 for that short stretch, in the pre-NavApp days, encouraged trucks to use the I-238/I-880 routing. Nowadays, they likely would have left it as Route 238, because NavApps would simply inform trucks which route to take. But I-238 was designated back in 1983.

And, to bring it back to the original topic, that's one reason for it being Route 15 S of I-805. It is 139(b) non-chargeable miles, so Caltrans could resign it whenever they think it is ready (unlike, for example, Route 210).

[pderocco]

I think the CA 15 designation should have become Interstate 15 when the "missing link" Wabash Blvd./40th St. Freeway was completed in 2000. Does the neighborhood the 40th St. Freeway passes through still have crime, drugs and prostitution problems like it did before the freeway was constructed?

There's been a dramatic drop in all three between 40th St and Central Ave. No one knows why.

[pderocco]

Having the I-15 designation end at I-805 instead wouldn't have been a bad idea, come to think of it.

Better yet, have I-805 go into downtown, and I-15 go down and merge with I-5 at the border crossing. I-15 deserves to go all the way to Mexico, since it also goes all the way to Canada.

[RZF]

Having the I-15 designation end at I-805 instead wouldn't have been a bad idea, come to think of it.

Better yet, have I-805 go into downtown, and I-15 go down and merge with I-5 at the border crossing. I-15 deserves to go all the way to Mexico, since it also goes all the way to Canada.

This makes logical sense, but of course, it will never happen. Wishful thinkin'.

[FredAkbar]

They are driving on a single road. They haven't made any turns. It's no more confusing then if you are driving along US 101 and it turns into Route 170, or vice versa.

I agree with the rest of your post, but this example I'm less sure about. US 101 doesn't just suddenly turn into CA-170, it intersects with it (and technically, going "straight" onto CA-170 is signed as a left exit). If you told me to take the Hollywood Freeway that's one thing, going straight onto CA-170 is staying on that road. But if you told me to take 101 North, I think that that would imply staying on the numbered route. Especially if I were new to the area, I'd follow the numbered freeway signs. The road being straight isn't always particularly meaningful, for example northbound at the 5/99 split, the road goes "straight" to become CA-99 but if your intention is to stay on the same route, you should take what looks visually like an exit to stay on I-5.

[Quillz]

They are driving on a single road. They haven't made any turns. It's no more confusing then if you are driving along US 101 and it turns into Route 170, or vice versa.

I agree with the rest of your post, but this example I'm less sure about. US 101 doesn't just suddenly turn into CA-170, it intersects with it (and technically, going "straight" onto CA-170 is signed as a left exit). If you told me to take the Hollywood Freeway that's one thing, going straight onto CA-170 is staying on that road. But if you told me to take 101 North, I think that that would imply staying on the numbered route. Especially if I were new to the area, I'd follow the numbered freeway signs. The road being straight isn't always particularly meaningful, for example northbound at the 5/99 split, the road goes "straight" to become CA-99 but if your intention is to stay on the same route, you should take what looks visually like an exit to stay on I-5.

That's always been an interesting historical holdover. Because it used to be US-99. I always wondered why the junction wasn't designed so the left lanes  didn't merge onto I-5 instead of having to be in the right lanes which then cross over. But I guess it was just a design choice back in the 70s or w/e the 5 opened.

[Max Rockatansky]

US 99 was already an established freeway and was going to pull the bulk of traffic.  It made sense to just allow the original configuration to remain rather than try to wedge US 99 onto a right hand exit.  Trying to reconfigure everything even now doesn't make financial sense.

[cahwyguy]

They are driving on a single road. They haven't made any turns. It's no more confusing then if you are driving along US 101 and it turns into Route 170, or vice versa.

I agree with the rest of your post, but this example I'm less sure about. US 101 doesn't just suddenly turn into CA-170, it intersects with it (and technically, going "straight" onto CA-170 is signed as a left exit). If you told me to take the Hollywood Freeway that's one thing, going straight onto CA-170 is staying on that road. But if you told me to take 101 North, I think that that would imply staying on the numbered route. Especially if I were new to the area, I'd follow the numbered freeway signs. The road being straight isn't always particularly meaningful, for example northbound at the 5/99 split, the road goes "straight" to become CA-99 but if your intention is to stay on the same route, you should take what looks visually like an exit to stay on I-5.

That's always been an interesting historical holdover. Because it used to be US-99. I always wondered why the junction wasn't designed so the left lanes  didn't merge onto I-5 instead of having to be in the right lanes which then cross over. But I guess it was just a design choice back in the 70s or w/e the 5 opened.

Route 170, to my knowledge, was NEVER US 99. US 99 was routed along San Fernando Road prior to the construction of I-5. What would become 170 was routed along Lankershim. Michael Ballard has some pictures showing that 170 perhaps might have been proposed to be US 6 for a short time.

Further, the "Left Exit" notion exists only NB. SB, it is a seamless transition from 170 into 101. In both directions, if you're in the HOV or #1/#2 lanes, the mainline just transitions from 101/170. There are similar transitions for the "straight line forward" for 101 to 134 to 210.

[Quillz]

I was referring to the Grapevine junction.

[FredAkbar]

There are similar transitions for the "straight line forward" for 101 to 134 to 210.

I think if the numbered highway that you're on ends (as with 170S at 101, 134E at 210) the traveler's default would be go keep going straight, because what else would they do. But if the numbered highway "turns" (as with 101N at 170, 101S at 134, even 210N at 134 I suppose) then someone if instructed to follow a numbered road would exit if necessary to stay on that numbered road.

But I've only driven through those intersections sporadically during my life, so I imagine if you are accustomed to the area it might be more natural to think of continuing on the straight road as the default option, regardless of the number change.

[mrsman]

There are similar transitions for the "straight line forward" for 101 to 134 to 210.

I think if the numbered highway that you're on ends (as with 170S at 101, 134E at 210) the traveler's default would be go keep going straight, because what else would they do. But if the numbered highway "turns" (as with 101N at 170, 101S at 134, even 210N at 134 I suppose) then someone if instructed to follow a numbered road would exit if necessary to stay on that numbered road.

But I've only driven through those intersections sporadically during my life, so I imagine if you are accustomed to the area it might be more natural to think of continuing on the straight road as the default option, regardless of the number change.

Following the number is always the straight option on a freeway, based on current signage practices, including the downplaying of the old freeway names.

[This is different from surface streets, where one would have to physically make a turn and likely the street name doesnt change, even if the highway number follows a turn.]

This even holds with regard to control cities, for the most part, at least in CA.  I-210 has the control of San Fernando (or Sacramento) within Pasadena even east of the 134/210 interchange and does not have 134's control, even though it is straight.  Similarly, US 101 Hollywood Fwy northbound has the control of Ventura, and not Sacramento (except for some signs) and US 101 Ventura Fwy has the control of Los Angeles and not Pasadena. 

So while the numbers have taken precedence and there is less and less use of signing the old freeway names on a regular basis, I do think that using the old freeway name as a control city (obviously in the proper direction) could be helpful.

For the most part, this is already done.  The entire Ventura Fwy (134 and 101) has Ventura as the westbound/northbound control until you reach Ventura.

But this should be done in other cases as well.  There is a trend to remove the Hollywood control over the Hollywood Fwy in favor of Ventura.  I think Hollywood and Ventura (or Hollywood and Los Angeles) should be cosigned at least at the major interchanges with other freeways between 5/170 and the East LA interchange.  At 5/170 I like Hollywood-Los Angeles (170) with Burbank-Los Angeles (5) to let people know that both routes are good ways to get into Downtown generally at that split.

101/134/210 as a straight line concept is great, and those that don't go that way that often probably don't view that as being all the same freeway, even though you generally keep left to stay on this straight line.  For this reason, I think it would be helpful that at 15/210, 215/210, and 10/210 in Redlands that there be supplemental signage directing traffic headed to the San Fernando Valley to use 210.  The Pasadena control is nice, but many travelers would first head into Los Angeles with the knowledge that SFV is part of LA, so if one takes 210, one really has all parts of the Valley at their disposal via 134 to 101 or 118.

[ran4sh]

But why should it even be allowed to be an interstate if trucks are prohibited?

That's like saying the Interstates inside I-285 (Georgia) should be re-designated because trucks are prohibited.

No one actually believes that would be a good idea, it's just understood that segments of Interstates in urban regions can have trucks banned as long as there's still a complete network of other Interstate(s) available as an alternative for trucks to use.

[RZF]

There are similar transitions for the "straight line forward" for 101 to 134 to 210.

I think if the numbered highway that you're on ends (as with 170S at 101, 134E at 210) the traveler's default would be go keep going straight, because what else would they do. But if the numbered highway "turns" (as with 101N at 170, 101S at 134, even 210N at 134 I suppose) then someone if instructed to follow a numbered road would exit if necessary to stay on that numbered road.

But I've only driven through those intersections sporadically during my life, so I imagine if you are accustomed to the area it might be more natural to think of continuing on the straight road as the default option, regardless of the number change.

Following the number is always the straight option on a freeway, based on current signage practices, including the downplaying of the old freeway names.

[This is different from surface streets, where one would have to physically make a turn and likely the street name doesnt change, even if the highway number follows a turn.]

This even holds with regard to control cities, for the most part, at least in CA.  I-210 has the control of San Fernando (or Sacramento) within Pasadena even east of the 134/210 interchange and does not have 134's control, even though it is straight.  Similarly, US 101 Hollywood Fwy northbound has the control of Ventura, and not Sacramento (except for some signs) and US 101 Ventura Fwy has the control of Los Angeles and not Pasadena. 

So while the numbers have taken precedence and there is less and less use of signing the old freeway names on a regular basis, I do think that using the old freeway name as a control city (obviously in the proper direction) could be helpful.

For the most part, this is already done.  The entire Ventura Fwy (134 and 101) has Ventura as the westbound/northbound control until you reach Ventura.

But this should be done in other cases as well.  There is a trend to remove the Hollywood control over the Hollywood Fwy in favor of Ventura.  I think Hollywood and Ventura (or Hollywood and Los Angeles) should be cosigned at least at the major interchanges with other freeways between 5/170 and the East LA interchange.  At 5/170 I like Hollywood-Los Angeles (170) with Burbank-Los Angeles (5) to let people know that both routes are good ways to get into Downtown generally at that split.

101/134/210 as a straight line concept is great, and those that don't go that way that often probably don't view that as being all the same freeway, even though you generally keep left to stay on this straight line.  For this reason, I think it would be helpful that at 15/210, 215/210, and 10/210 in Redlands that there be supplemental signage directing traffic headed to the San Fernando Valley to use 210.  The Pasadena control is nice, but many travelers would first head into Los Angeles with the knowledge that SFV is part of LA, so if one takes 210, one really has all parts of the Valley at their disposal via 134 to 101 or 118.

Some signage right by the interchange that says "To SF Valley/Ventura use 210" and below that "To Downtown Los Angeles use 10".