Highway engineers these days hate cloverleafs. They are seen as sources of congestion and accidents due to the weaving between vehicles entering and exiting. Many of them have been converted into Parclos on freeway arterial interchanges or into cloverstacks on freeway-freeway interchanges. But if you look at Google Maps, you see that the Bay Area still has tons of them, even at the extremely busy 880-101 interchange. So what is responsible for this situation? It seems like getting rid of them would be a fairly simple way to increase traffic capacity and safety.
Are you effing kidding me? What is your malfunction with this obsession with trashing the San Francisco Bay Area? Are things just that peachy and rosy in Massachusetts that you can't let some place your family has origins go?
Quote from: Max Rockatansky on October 25, 2020, 10:56:29 AM
Are you effing kidding me? What is your malfunction with this obsession with trashing the San Francisco Bay Area? Are things just that peachy and rosy in Massachusetts that you can't let some place your family has origins go?
I wasn't being snarky. I was just asking.
Massachusetts has a whole bunch of cloverleaves, too.
Quote from: 1 on October 25, 2020, 11:11:57 AM
Massachusetts has a whole bunch of cloverleaves, too.
I know, I've had the pleasure of being one of those sad commuters using the I-93/I-95 interchange in Reading.
Quote from: kernals12 on October 25, 2020, 11:07:11 AM
Quote from: Max Rockatansky on October 25, 2020, 10:56:29 AM
Are you effing kidding me? What is your malfunction with this obsession with trashing the San Francisco Bay Area? Are things just that peachy and rosy in Massachusetts that you can't let some place your family has origins go?
I wasn't being snarky. I was just asking.
But come off that way by the way you phrase things, especially when you look at the cumulative sum of what you have said regarding the Bay Area (the thread last night in particular was very clear regarding your opinions). To that end I too don't necessarily agree with how highway based transportation in the Bay has been historically handled, especially when it comes to a new crossing of San Francisco Bay. I'm also not a fan of proposing tolls for State Highways that have always been free (especially 37 and 12). But to than end I don't live in the Bay Area and I can't do much as a non-resident in terms of fighting things like that.
About the best thing I can think to do is talk about those issues in a realistic and tactful manner. About as political as I ever have really gotten with the road community in California was getting behind SB1 a couple years ago. The irony there was that SB1 was being contested heavily in the Central Valley due to a certain set portions of the funds drawn being set aside for the HSR. For my part I saw the benefits of SB1 in terms of highway reinvestment as far out weighing any benefits to the HSR. For what it's worth, I don't know if I changed anyone's opinion but I can say that District 6 seems to have benefited greatly from SB1. That in my opinion is how you should be approaching issues like what you see in the San Francisco Bay Area. Try to understand that for every single good Highway idea there are a lot of really bad ones that have come up also. You have a lot of distrust towards highway development due to the FritzOwl level of dystopian ideas the Division of Highways once had for San Francisco.
The real answer your question above is that facilities are old and Caltrans District 4 doesn't have the funding to upgrade them. For whatever reason (which may be illustrated above) District 4 seems to be not too interested in using things like SB1 for stuff like ramp replacements and signage upgrades. Really the only true development you'll see widely in the Bay Area right now is the construction of toll lanes on I-880/Nimitz Freeway and I-680.
It's not that complicated. The Bay Area started building freeways early, so a lot of cloverleafs were built. They've been playing catchup forever, trying to do seismic retrofits and repair earthquake damage and add capacity where possible. Real estate and construction costs are high so only a few projects can get worked on. Some of the interchanges with poor geometry have been addressed, but there's plenty left.
Quote from: kkt on October 25, 2020, 11:30:21 AM
It's not that complicated. The Bay Area started building freeways early, so a lot of cloverleafs were built. They've been playing catchup forever, trying to do seismic retrofits and repair earthquake damage and add capacity where possible. Real estate and construction costs are high so only a few projects can get worked on. Some of the interchanges with poor geometry have been addressed, but there's plenty left.
Cloverleaf take up a lot of space, so using more space efficient designs could free up valuable land
You are not factually correct. A quick scan of the nine Bay Area counties shows that fewer than 7% of the interchanges are three or four-loop cloverleaf designs. There used to be more, but again, actual research shows that many of them have been converted to parclos or other designs, just as you have suggested.
(there is a small margin of error possible here, since this involved my going through the interchange lists and comparing them to maps)
I'm not going to spend a lot of time on your blatant and immature bias against a region that you don't have any actual experience living in, but if you're going to show your bias, at least get your facts straight.
The Bay Area really doesn't have that many cloverleaves. It's more than most of the west coast, but less than much of the rest of the country (New England and the east coast being the most prolific in this regard). In the Midwest, Minnesota has quite a few, as does Wisconsin.
The reason why 880-101 hasn't been rebuilt is cost.
It would be extremely expensive to put in flyovers in such a heavily urbanized area.
Yes, it's cost, also there are other interchanges too close to 880-101 for good practice. To meet current best practices they'd probably have to rebuild a mile from the actual interchange in each direction with collector-distributor roads. Which is part of the reason the cost is so high...
I-780 @ I-80 interchange is cloverleaf. But that was when I-80 was then co-signed with US-40.
Quote from: kkt on October 25, 2020, 05:18:12 PM
Yes, it's cost, also there are other interchanges too close to 880-101 for good practice. To meet current best practices they'd probably have to rebuild a mile from the actual interchange in each direction with collector-distributor roads. Which is part of the reason the cost is so high...
Yes, I should have been more specific. It is for these reasons that you would need long, expensive flyovers.
Quote from: STLmapboy on October 25, 2020, 02:46:09 PM
The Bay Area really doesn't have that many cloverleaves. It's more than most of the west coast, but less than much of the rest of the country (New England and the east coast being the most prolific in this regard). In the Midwest, Minnesota has quite a few, as does Wisconsin.
Could be mistaken, but I think Illinois has and generally used more than Wisconsin did. I'm only finding I-43 at WI 100 around Milwaukee, possibly a few
extinct once planned ones on I-94 south of I-894, whereas Chicagoland has multiple cloverleafs in a row on some corridors (I-55 east of I-355 for a bit). They were also heavily used in other parts of Illinois (three in a row on I-55 in Springfield, usually at least one in the other decent sized areas). Wisconsin seems quite good at removing the ones they had.
I think Indiana may have also had more the Wisconsin until many of them were reconfigured into other interchange types.
Quote from: kernals12 on October 25, 2020, 01:52:51 PM
Cloverleaf take up a lot of space, so using more space efficient designs could free up valuable land
It's funny you say this because of your reference to the 880-101 interchange in San Jose. The main reason why that interchange hasn't been upgraded is because there is
not enough space to build a couple of simple flyovers no less a full stack without having to "eminent domain" a significant number of properties around it.
Quote from: myosh_tino on October 25, 2020, 10:31:35 PM
Quote from: kernals12 on October 25, 2020, 01:52:51 PM
Cloverleaf take up a lot of space, so using more space efficient designs could free up valuable land
It's funny you say this because of your reference to the 880-101 interchange in San Jose. The main reason why that interchange hasn't been upgraded is because there is not enough space to build a couple of simple flyovers no less a full stack without having to "eminent domain" a significant number of properties around it.
For freeway to arterial interchanges, SPUIs, Diamonds, Parclos, or DDIs would require less space than a Cloveleaf.
Quote from: kernals12 on October 25, 2020, 10:58:01 PM
Quote from: myosh_tino on October 25, 2020, 10:31:35 PM
Quote from: kernals12 on October 25, 2020, 01:52:51 PM
Cloverleaf take up a lot of space, so using more space efficient designs could free up valuable land
It's funny you say this because of your reference to the 880-101 interchange in San Jose. The main reason why that interchange hasn't been upgraded is because there is not enough space to build a couple of simple flyovers no less a full stack without having to "eminent domain" a significant number of properties around it.
For freeway to arterial interchanges, SPUIs, Diamonds, Parclos, or DDIs would require less space than a Cloveleaf.
880 to 101 would be a freeway to freeway interchange. It would also be somewhat limited in height due to the approach paths for San Jose Airport.
Quote from: kkt on October 25, 2020, 11:35:25 PM
880 to 101 would be a freeway to freeway interchange. It would also be somewhat limited in height due to the approach paths for San Jose Airport.
kkt is correct - the San Jose airport is the primary reason for the lack of an upgrade to this interchange. You can't add ramps above the interchange due to the approach paths to the airport. (This is also why there isn't an interchange between I-880 and CA 87.) Also, you can't put ramps below the interchange due to the high water table in that area. US 101 (the lower of the two freeways) has intermittent pavement flooding problems, despite Caltrans having multiple pumps to keep the roadway dry. So, we're stuck with the cloverleaf configuration. :angry:
Quote from: Revive 755 on October 25, 2020, 10:10:58 PM
Quote from: STLmapboy on October 25, 2020, 02:46:09 PM
The Bay Area really doesn't have that many cloverleaves. It's more than most of the west coast, but less than much of the rest of the country (New England and the east coast being the most prolific in this regard). In the Midwest, Minnesota has quite a few, as does Wisconsin.
Could be mistaken, but I think Illinois has and generally used more than Wisconsin did. I'm only finding I-43 at WI 100 around Milwaukee, possibly a few extinct once planned ones on I-94 south of I-894, whereas Chicagoland has multiple cloverleafs in a row on some corridors (I-55 east of I-355 for a bit). They were also heavily used in other parts of Illinois (three in a row on I-55 in Springfield, usually at least one in the other decent sized areas). Wisconsin seems quite good at removing the ones they had.
I think Indiana may have also had more the Wisconsin until many of them were reconfigured into other interchange types.
I grew up in Wisconsin and thought there were a fair number of cloverleafs. I-43@WI 23. I-90/94@US 151. I-94@US 53. US 53@WI 29 is one of the more wacko cloverleafs I've seen. I-43@I-90 (from back when it was WI 15@I-90). I wish they had built one at US/I-41@US 151 instead of the stupid diamond interchange plopping a couple stop lights on what is otherwise a non-stop drive from Madison to Green Bay.
Quote from: Max Rockatansky on October 25, 2020, 11:25:33 AM
Quote from: kernals12 on October 25, 2020, 11:07:11 AM
Quote from: Max Rockatansky on October 25, 2020, 10:56:29 AM
Are you effing kidding me? What is your malfunction with this obsession with trashing the San Francisco Bay Area? Are things just that peachy and rosy in Massachusetts that you can't let some place your family has origins go?
I wasn't being snarky. I was just asking.
But come off that way by the way you phrase things, especially when you look at the cumulative sum of what you have said regarding the Bay Area (the thread last night in particular was very clear regarding your opinions). To that end I too don't necessarily agree with how highway based transportation in the Bay has been historically handled, especially when it comes to a new crossing of San Francisco Bay. I'm also not a fan of proposing tolls for State Highways that have always been free (especially 37 and 12). But to than end I don't live in the Bay Area and I can't do much as a non-resident in terms of fighting things like that.
About the best thing I can think to do is talk about those issues in a realistic and tactful manner. About as political as I ever have really gotten with the road community in California was getting behind SB1 a couple years ago. The irony there was that SB1 was being contested heavily in the Central Valley due to a certain set portions of the funds drawn being set aside for the HSR. For my part I saw the benefits of SB1 in terms of highway reinvestment as far out weighing any benefits to the HSR. For what it's worth, I don't know if I changed anyone's opinion but I can say that District 6 seems to have benefited greatly from SB1. That in my opinion is how you should be approaching issues like what you see in the San Francisco Bay Area. Try to understand that for every single good Highway idea there are a lot of really bad ones that have come up also. You have a lot of distrust towards highway development due to the FritzOwl level of dystopian ideas the Division of Highways once had for San Francisco.
The real answer your question above is that facilities are old and Caltrans District 4 doesn't have the funding to upgrade them. For whatever reason (which may be illustrated above) District 4 seems to be not too interested in using things like SB1 for stuff like ramp replacements and signage upgrades. Really the only true development you'll see widely in the Bay Area right now is the construction of toll lanes on I-880/Nimitz Freeway and I-680.
you do know that he just wrote text and you really can't tell what his emotions are right? texting is the worst form of communication and assuming a persons emotions from text is ill advised. emojis help but it's still not perfect.
Quote from: silverback1065 on October 26, 2020, 08:40:30 PM
Quote from: Max Rockatansky on October 25, 2020, 11:25:33 AM
Quote from: kernals12 on October 25, 2020, 11:07:11 AM
Quote from: Max Rockatansky on October 25, 2020, 10:56:29 AM
Are you effing kidding me? What is your malfunction with this obsession with trashing the San Francisco Bay Area? Are things just that peachy and rosy in Massachusetts that you can't let some place your family has origins go?
I wasn't being snarky. I was just asking.
But come off that way by the way you phrase things, especially when you look at the cumulative sum of what you have said regarding the Bay Area (the thread last night in particular was very clear regarding your opinions). To that end I too don't necessarily agree with how highway based transportation in the Bay has been historically handled, especially when it comes to a new crossing of San Francisco Bay. I'm also not a fan of proposing tolls for State Highways that have always been free (especially 37 and 12). But to than end I don't live in the Bay Area and I can't do much as a non-resident in terms of fighting things like that.
About the best thing I can think to do is talk about those issues in a realistic and tactful manner. About as political as I ever have really gotten with the road community in California was getting behind SB1 a couple years ago. The irony there was that SB1 was being contested heavily in the Central Valley due to a certain set portions of the funds drawn being set aside for the HSR. For my part I saw the benefits of SB1 in terms of highway reinvestment as far out weighing any benefits to the HSR. For what it's worth, I don't know if I changed anyone's opinion but I can say that District 6 seems to have benefited greatly from SB1. That in my opinion is how you should be approaching issues like what you see in the San Francisco Bay Area. Try to understand that for every single good Highway idea there are a lot of really bad ones that have come up also. You have a lot of distrust towards highway development due to the FritzOwl level of dystopian ideas the Division of Highways once had for San Francisco.
The real answer your question above is that facilities are old and Caltrans District 4 doesn't have the funding to upgrade them. For whatever reason (which may be illustrated above) District 4 seems to be not too interested in using things like SB1 for stuff like ramp replacements and signage upgrades. Really the only true development you'll see widely in the Bay Area right now is the construction of toll lanes on I-880/Nimitz Freeway and I-680.
you do know that he just wrote text and you really can't tell what his emotions are right? texting is the worst form of communication and assuming a persons emotions from text is ill advised. emojis help but it's still not perfect.
I refer to:
https://www.aaroads.com/forum/index.php?topic=27559.msg2529175#msg2529175
Suffice to say, a lot can be inferred after reading the "rant." And to that end, I disagree. I've taken written statements from people for twenty years and there certainly is a lot you can take from written word. You can clearly convey emotions, infer them, or even subtly sneak them into writing.
Quote from: Max Rockatansky on October 26, 2020, 08:46:06 PM
Quote from: silverback1065 on October 26, 2020, 08:40:30 PM
Quote from: Max Rockatansky on October 25, 2020, 11:25:33 AM
Quote from: kernals12 on October 25, 2020, 11:07:11 AM
Quote from: Max Rockatansky on October 25, 2020, 10:56:29 AM
Are you effing kidding me? What is your malfunction with this obsession with trashing the San Francisco Bay Area? Are things just that peachy and rosy in Massachusetts that you can't let some place your family has origins go?
I wasn't being snarky. I was just asking.
But come off that way by the way you phrase things, especially when you look at the cumulative sum of what you have said regarding the Bay Area (the thread last night in particular was very clear regarding your opinions). To that end I too don't necessarily agree with how highway based transportation in the Bay has been historically handled, especially when it comes to a new crossing of San Francisco Bay. I'm also not a fan of proposing tolls for State Highways that have always been free (especially 37 and 12). But to than end I don't live in the Bay Area and I can't do much as a non-resident in terms of fighting things like that.
About the best thing I can think to do is talk about those issues in a realistic and tactful manner. About as political as I ever have really gotten with the road community in California was getting behind SB1 a couple years ago. The irony there was that SB1 was being contested heavily in the Central Valley due to a certain set portions of the funds drawn being set aside for the HSR. For my part I saw the benefits of SB1 in terms of highway reinvestment as far out weighing any benefits to the HSR. For what it's worth, I don't know if I changed anyone's opinion but I can say that District 6 seems to have benefited greatly from SB1. That in my opinion is how you should be approaching issues like what you see in the San Francisco Bay Area. Try to understand that for every single good Highway idea there are a lot of really bad ones that have come up also. You have a lot of distrust towards highway development due to the FritzOwl level of dystopian ideas the Division of Highways once had for San Francisco.
The real answer your question above is that facilities are old and Caltrans District 4 doesn't have the funding to upgrade them. For whatever reason (which may be illustrated above) District 4 seems to be not too interested in using things like SB1 for stuff like ramp replacements and signage upgrades. Really the only true development you'll see widely in the Bay Area right now is the construction of toll lanes on I-880/Nimitz Freeway and I-680.
you do know that he just wrote text and you really can't tell what his emotions are right? texting is the worst form of communication and assuming a persons emotions from text is ill advised. emojis help but it's still not perfect.
I refer to:
https://www.aaroads.com/forum/index.php?topic=27559.msg2529175#msg2529175
Suffice to say, a lot can be inferred after reading the "rant." And to that end, I disagree. I've taken written statements from people for twenty years and there certainly is a lot you can take from written word. You can clearly convey emotions, infer them, or even subtly sneak them into writing.
Surely you understand that what you put was a bit on the long side, though, right? It's better than kernals' linked braindump, for sure, but it's still a bit of a tl;dr situation.
Quote from: STLmapboy on October 27, 2020, 10:55:50 PM
Quote from: Max Rockatansky on October 26, 2020, 08:46:06 PM
Quote from: silverback1065 on October 26, 2020, 08:40:30 PM
Quote from: Max Rockatansky on October 25, 2020, 11:25:33 AM
Quote from: kernals12 on October 25, 2020, 11:07:11 AM
Quote from: Max Rockatansky on October 25, 2020, 10:56:29 AM
Are you effing kidding me? What is your malfunction with this obsession with trashing the San Francisco Bay Area? Are things just that peachy and rosy in Massachusetts that you can't let some place your family has origins go?
I wasn't being snarky. I was just asking.
But come off that way by the way you phrase things, especially when you look at the cumulative sum of what you have said regarding the Bay Area (the thread last night in particular was very clear regarding your opinions). To that end I too don't necessarily agree with how highway based transportation in the Bay has been historically handled, especially when it comes to a new crossing of San Francisco Bay. I'm also not a fan of proposing tolls for State Highways that have always been free (especially 37 and 12). But to than end I don't live in the Bay Area and I can't do much as a non-resident in terms of fighting things like that.
About the best thing I can think to do is talk about those issues in a realistic and tactful manner. About as political as I ever have really gotten with the road community in California was getting behind SB1 a couple years ago. The irony there was that SB1 was being contested heavily in the Central Valley due to a certain set portions of the funds drawn being set aside for the HSR. For my part I saw the benefits of SB1 in terms of highway reinvestment as far out weighing any benefits to the HSR. For what it's worth, I don't know if I changed anyone's opinion but I can say that District 6 seems to have benefited greatly from SB1. That in my opinion is how you should be approaching issues like what you see in the San Francisco Bay Area. Try to understand that for every single good Highway idea there are a lot of really bad ones that have come up also. You have a lot of distrust towards highway development due to the FritzOwl level of dystopian ideas the Division of Highways once had for San Francisco.
The real answer your question above is that facilities are old and Caltrans District 4 doesn't have the funding to upgrade them. For whatever reason (which may be illustrated above) District 4 seems to be not too interested in using things like SB1 for stuff like ramp replacements and signage upgrades. Really the only true development you'll see widely in the Bay Area right now is the construction of toll lanes on I-880/Nimitz Freeway and I-680.
you do know that he just wrote text and you really can't tell what his emotions are right? texting is the worst form of communication and assuming a persons emotions from text is ill advised. emojis help but it's still not perfect.
I refer to:
https://www.aaroads.com/forum/index.php?topic=27559.msg2529175#msg2529175
Suffice to say, a lot can be inferred after reading the "rant." And to that end, I disagree. I've taken written statements from people for twenty years and there certainly is a lot you can take from written word. You can clearly convey emotions, infer them, or even subtly sneak them into writing.
Surely you understand that what you put was a bit on the long side, though, right? It's better than kernals' linked braindump, for sure, but it's still a bit of a tl;dr situation.
The least I could do was ask for the annoying angst for the Bay Area bashing to stop. I'm all for constructive criticism of any given area, but that hasn't what OP has been putting forth thus far on the forum. At this point these threads have swung to something more productive in spite of despite what the intentions may have been at the beginning. At this point commenting on it further probably doesn't amount to much if we can stay on track with the topics on this board.
^^^^^^^^^^^
Much of the overall criticism directed at the state of transportation (including highways, of course) in the Bay Area can be attributed to the prioritizations of particular modes and objectives by the combination of the various agencies that contribute or even "vet" the projects that are presented to their collective planners -- and how the area's legislators (all the way from city councils and county supervisors to state assemblypersons and senators) can and do function as an effective "valve" on the project pipeline. When I first resided in the South Bay (1975-86) there was always some level of bias toward collective transit and against expansion of facilities for individual/commercial automotive travel -- but at that time it wasn't sufficient to derail major road projects such as the planning and ROW acquisition for the CA 85 freeway and the slow but steady progress on CA 87. However, there was always a bit of mitigation involved, such as the truck ban on 85 south of I-280 and the narrowing of that facility between CA 17 and I-280 from 4 overall lanes (including one HOV) down to 3, including the HOV; but that was largely attributed to Saratoga/Los Gatos NIMBY's putting their 200 cents in!
More recently both San Jose (city) and Santa Clara (county) planners are firmly in the "urbanism" camp, and since projects within metro bounds are vetted by all agencies, not just Caltrans, priorities as well have changed -- and unless there's a specific safety issue, older interchange modifications generally are well down the "to do" list. But this is not a specific Bay Area issue -- and while this area was among the first to manifest this sea change in priorities, it has certainly been matched elsewhere in the state, like L.A. and its virtual new-freeway ban in the L.A. basin; and definitely with Sacramento, which hasn't seen a completely new freeway facility (although CA 99 was upgraded to a full freeway north of I-5) since 1981, when I-5 was completed south of town. And here in San Jose, one can witness first-hand that priority switch with the in-progress electrification of the Caltrans commute rail line (those facilities to be shared with HSR if and when it ever gets here!), a project well into the hundreds of millions. But right now one long-pressing road/connectivity issue is being considered -- reconstructing the CA 262 Mission Blvd. connection between I-880 and I-680 into a full freeway to eliminate a peak-hour bottleneck in the Warm Springs area that affects local traffic as well -- a situation that has prompted renewed public interest in the concept. We'll just have to see what transpires regarding both whether such a project gets out of the starting blocks and how timely the funding process plays out. 262 is one case where the concept of "induced demand" is a ship that sailed when the original CA 237 freeway connecting the two N-S Interstates was cancelled -- about 3 out of 4 drivers heading to I-680 and points beyond (Pleasanton, Livermore, Tracy, etc.) crowd onto 262 since it's the shortest connection between the freeways. So far there's been no massive or even vocal pissing and moaning from the "woke" and/or urbanist sector regarding the preliminary planning/design for the freeway upgrade; we'll see what happens when a final design is completed and proffered.
But while the upper reaches of US 101 -- particularly in San Mateo County -- have seen little changes to the original late-50's/early-60's interchange configurations, the three high-traffic former cloverleafs -- Trimble/De La Cruz (county G6), San Tomas Expressway (G4), and Lawrence Expressway (G2) have been partially reconfigured in the last couple of decades; the first is now a standard parclo for NB 101 but retained the double-loop cloverleaf for SB 101 (sans C/D lanes and thus a traffic PITA!); the other ones are now cookie-cutter parclos. Whether these mods are extended northward at some point is yet TBD -- but at least some progress has been made.
The parclos on I-880 in Fremont and Union City used to be full cloverleafs (obvious in satellite imagery) so it's not like nothing has been done to upgrade the interchanges.
Quote from: Max Rockatansky on October 25, 2020, 10:56:29 AM
Are you effing kidding me? What is your malfunction with this obsession with trashing the San Francisco Bay Area? Are things just that peachy and rosy in Massachusetts that you can't let some place your family has origins go?
This was hands down the most ridiculously defensive response I've seen on this forum. That's saying a lot.
At least our cloverleaves are poopless out in MA...
Quote from: SectorZ on October 29, 2020, 08:57:53 PM
Quote from: Max Rockatansky on October 25, 2020, 10:56:29 AM
Are you effing kidding me? What is your malfunction with this obsession with trashing the San Francisco Bay Area? Are things just that peachy and rosy in Massachusetts that you can't let some place your family has origins go?
This was hands down the most ridiculously defensive response I've seen on this forum. That's saying a lot.
At least our cloverleaves are poopless out in MA...
How is that being defensive? Are you saying I'm defensive because I don't particularly care for some random new user from Massachusetts having a constant tone of negativity towards the a Bay Area because his Dad didn't like it? What new ground are we exactly covering here that hasn't been discussed about a million times by now?
And I'm I getting it right that you are implying that I'm somehow defending the current state of road based transportation in the Bay Area with the "poopless" statement? If that's the case of you clearly haven't read much on this board. More so, is that a hot take on the homeless situation in the Bay Area?
Okay... Let's have more discussion about Bay Area cloverleaf interchanges and less commentary about the merits/motivations/whatever of individual users' replies... Thanks.
Quote from: mapman on October 26, 2020, 12:52:16 AM
Quote from: kkt on October 25, 2020, 11:35:25 PM
880 to 101 would be a freeway to freeway interchange. It would also be somewhat limited in height due to the approach paths for San Jose Airport.
kkt is correct - the San Jose airport is the primary reason for the lack of an upgrade to this interchange. You can't add ramps above the interchange due to the approach paths to the airport. (This is also why there isn't an interchange between I-880 and CA 87.) Also, you can't put ramps below the interchange due to the high water table in that area. US 101 (the lower of the two freeways) has intermittent pavement flooding problems, despite Caltrans having multiple pumps to keep the roadway dry. So, we're stuck with the cloverleaf configuration. :angry:
It's manifestly untrue that a flyover from I-880 to US-101 wouldn't be allowed because of the approach path to SJC. In addition to do being able to do it in the existing headroom, the blast fence at the end of runways 30 is almost as high as the flyover would have to be. SJC may be a reason for not making a US-101/CASR-87 interchange, but it certainly isn't the reason that US-101/I-880 hasn't been done, attempted, started, or well studied. My guesses are any combination of the following:
1) Construction costs
2) Possible Land Acquisition cost
3) Construction impact upon existing traffic (irony of ironies)
4) Recent construction in the area
5) Urbanist opposition to helping roads in any way.
US 101 - CA 92 was one terrible cloverleaf that's been made much better. Much of the work was done in the early 1980s, if I remember right.
Quote from: sparker on October 29, 2020, 07:43:38 PM
More recently both San Jose (city) and Santa Clara (county) planners are firmly in the "urbanism" camp, and since projects within metro bounds are vetted by all agencies, not just Caltrans, priorities as well have changed -- and unless there's a specific safety issue, older interchange modifications generally are well down the "to do" list. But this is not a specific Bay Area issue -- and while this area was among the first to manifest this sea change in priorities, it has certainly been matched elsewhere in the state, like L.A. and its virtual new-freeway ban in the L.A. basin; and definitely with Sacramento, which hasn't seen a completely new freeway facility (although CA 99 was upgraded to a full freeway north of I-5) since 1981, when I-5 was completed south of town.
Would the Capital Southeast Corridor project count as new construction for the Sacramento region? Though I don't think it is intended to be freeway (yet).
Quote from: sparker on October 29, 2020, 07:43:38 PM
But right now one long-pressing road/connectivity issue is being considered -- reconstructing the CA 262 Mission Blvd. connection between I-880 and I-680 into a full freeway to eliminate a peak-hour bottleneck in the Warm Springs area that affects local traffic as well -- a situation that has prompted renewed public interest in the concept. We'll just have to see what transpires regarding both whether such a project gets out of the starting blocks and how timely the funding process plays out. 262 is one case where the concept of "induced demand" is a ship that sailed when the original CA 237 freeway connecting the two N-S Interstates was cancelled -- about 3 out of 4 drivers heading to I-680 and points beyond (Pleasanton, Livermore, Tracy, etc.) crowd onto 262 since it's the shortest connection between the freeways. So far there's been no massive or even vocal pissing and moaning from the "woke" and/or urbanist sector regarding the preliminary planning/design for the freeway upgrade; we'll see what happens when a final design is completed and proffered.
I'll actually start a separate thread for this as it is interesting in of itself for many historic and current reasons!
Quote from: kkt on October 29, 2020, 11:01:14 PM
US 101 - CA 92 was one terrible cloverleaf that's been made much better. Much of the work was done in the early 1980s, if I remember right.
Looking at HistoricAerials, the work to upgrade that interchange to add the two flyovers (SB 101 to EB 92, NB 101 to WB 92) occurred sometime between 1984 and 1988. There are stubs for flyovers that were never built (EB 92 to NB 101 and WB 92 to SB 101) during that project.
Quote from: kkt on October 29, 2020, 11:01:14 PM
US 101 - CA 92 was one terrible cloverleaf that's been made much better. Much of the work was done in the early 1980s, if I remember right.
A more recent elimination of a cloverleaf was CA 92 and CA 82. It's now a rather nice parclo.
The cloverleaf at I-680 / CA-4 is another example of an awful interchange that has had few improvements. Back in the early 2000's, around the same time as the HOV lanes were added to that stretch of I-680 they moved the I-680 merge lanes onto a set of parallel C/D lanes, but otherwise it's nearly the same as it was when built back in the 1960's. Improvements have been planned for this interchange for a good 20 years now, but funding has not been made available yet. The weaving situation on CA-4 is made even worse by the short spacing of the adjacent Pacheco Blvd exits. CA-4 is currently undergoing widening between Morello and CA-242 which will add a third lane in each direction, but no other improvements to the interchange are funded at this time.
The cloverleaf at I-680 and I-580 benefitted significantly when they added a flyover ramp from I-680 South to I-580 East, but a huge bottleneck still exists because of backups on the loop movement from I-580 West to I-680 South.
Quote from: michravera on October 29, 2020, 10:34:52 PM
Quote from: mapman on October 26, 2020, 12:52:16 AM
Quote from: kkt on October 25, 2020, 11:35:25 PM
880 to 101 would be a freeway to freeway interchange. It would also be somewhat limited in height due to the approach paths for San Jose Airport.
kkt is correct - the San Jose airport is the primary reason for the lack of an upgrade to this interchange. You can't add ramps above the interchange due to the approach paths to the airport. (This is also why there isn't an interchange between I-880 and CA 87.) Also, you can't put ramps below the interchange due to the high water table in that area. US 101 (the lower of the two freeways) has intermittent pavement flooding problems, despite Caltrans having multiple pumps to keep the roadway dry. So, we're stuck with the cloverleaf configuration. :angry:
It's manifestly untrue that a flyover from I-880 to US-101 wouldn't be allowed because of the approach path to SJC. In addition to do being able to do it in the existing headroom, the blast fence at the end of runways 30 is almost as high as the flyover would have to be. SJC may be a reason for not making a US-101/CASR-87 interchange, but it certainly isn't the reason that US-101/I-880 hasn't been done, attempted, started, or well studied. My guesses are any combination of the following:
1) Construction costs
2) Possible Land Acquisition cost
3) Construction impact upon existing traffic (irony of ironies)
4) Recent construction in the area
5) Urbanist opposition to helping roads in any way.
I admit I'm not an expert on this, but I don't see how the I-880/US-101 interchange could affect the operations of the airport in any way. Assuming that the interchange is the red circle and the runways are the green lines, and I just can't see how a plane could swoop around from that interchange to line up with either of those two runways.
(https://i.imgur.com/wdTyWnz.png)
I'm not an expert either, but I wonder what an aircraft's go-around flight would look like when they have to abort a landing?
Quote from: kkt on October 30, 2020, 09:34:15 PM
I'm not an expert either, but I wonder what an aircraft's go-around flight would look like when they have to abort a landing?
As someone who has landed, gone around, aborted landings, and done a large number of touch-and-go and stop-and-go landings and missed approaches on both runway 30R/12L and a few on 30L/12R, I can tell you that I-880 and US-101 doesn't even enter into the calculation of anything that you do at SJC. When you abort a landing and either go around or go missed, the first thing that you do is to fly the runway heading for some distance (usually until you are basically over the Bay on the 30 runways and until you have passed Downtown on the 12 runways) before you start a turn. About the only thing that the I-880/US-101 interchange is any good for is a reference point to use for your (really) tight traffic pattern (which is 1000 ft MSL or about 950 ft AGL) and, even then, you usually are well outside of it. Most of the time, you are at about 400ft MSL (350 ft AGL) when you come over I-880. When they give you straight in, you usually keep it to over 2000 (sometimes cheat it to 1500) over Downtown. When I was flying a lot more, I often heard advisories of unlighted construction cranes as high as almost 400 ft within a mile of the airport. Basically, no one flies below 500 ft AGL unless they have just taken off or are landing in the next 10-20 seconds, or are having troubles. The parking garage and likely the blast fence are higher than a flyover ramp would have to be and they are on the airport property. An I-880/US-101 interchange improvement may not get built in time to matter, for a lot of reasons, but the airport isn't one of them.
Quote from: michravera on October 29, 2020, 10:34:52 PM
Quote from: mapman on October 26, 2020, 12:52:16 AM
Quote from: kkt on October 25, 2020, 11:35:25 PM
880 to 101 would be a freeway to freeway interchange. It would also be somewhat limited in height due to the approach paths for San Jose Airport.
kkt is correct - the San Jose airport is the primary reason for the lack of an upgrade to this interchange. You can't add ramps above the interchange due to the approach paths to the airport. (This is also why there isn't an interchange between I-880 and CA 87.) Also, you can't put ramps below the interchange due to the high water table in that area. US 101 (the lower of the two freeways) has intermittent pavement flooding problems, despite Caltrans having multiple pumps to keep the roadway dry. So, we're stuck with the cloverleaf configuration. :angry:
It's manifestly untrue that a flyover from I-880 to US-101 wouldn't be allowed because of the approach path to SJC. In addition to do being able to do it in the existing headroom, the blast fence at the end of runways 30 is almost as high as the flyover would have to be. SJC may be a reason for not making a US-101/CASR-87 interchange, but it certainly isn't the reason that US-101/I-880 hasn't been done, attempted, started, or well studied. My guesses are any combination of the following:
1) Construction costs
2) Possible Land Acquisition cost
3) Construction impact upon existing traffic (irony of ironies)
4) Recent construction in the area
5) Urbanist opposition to helping roads in any way.
My initial guess as a local would be the Koll "North 4th" industrial park immediately adjacent to the SB 101>SB 880 ramp; Koll owns a shitload of commercial property in Santa Clara County and seems to have a great deal of political pull. That industrial park was built in the early '80's (my business almost relocated there in '86), displacing a trailer park and old steel wartime industrial structures, so it's likely that the company would rather not have to downsize their holdings. Since 880 makes a 45-degree turn through the 101 interchange, it's probable that any revision would to some degree "straightline" that curve, which itself would require movement west -- right into the Koll park. Also the UP Milpitas branch, which is an active rail line, crosses 101 immediately south of the interchange; it would likely pose as an obstacle to expansion in
that direction. There's just no solution to 101/880 that wouldn't require tweaking the nose of corporate interests that would undoubtedly push back with every tool in the bag!
The 1 to 2 story light industrial park adjacent to the interchange doesn't seem like that much of a problem. This is not homes or landmark structures that people have fallen in love with. A good buyout offer, relocation expenses, and a generous timeline for relocation should be sufficient. Same for the other three sides, really, the car- and truck-oriented businesses there should be possible to relocate. The railroad would be a problem to move, but it's 1600 feet from the center of the interchange so it seems like it should be possible to rebuild the interchange while leaving it in place.
The adjacent interchanges along both I-880 and US 101 are closer than would be ideal.
Quote from: michravera on October 31, 2020, 04:30:57 AM
As someone who has landed, gone around, aborted landings, and done a large number of touch-and-go and stop-and-go landings and missed approaches on both runway 30R/12L and a few on 30L/12R, I can tell you that I-880 and US-101 doesn't even enter into the calculation of anything that you do at SJC. When you abort a landing and either go around or go missed, the first thing that you do is to fly the runway heading for some distance (usually until you are basically over the Bay on the 30 runways and until you have passed Downtown on the 12 runways) before you start a turn. About the only thing that the I-880/US-101 interchange is any good for is a reference point to use for your (really) tight traffic pattern (which is 1000 ft MSL or about 950 ft AGL) and, even then, you usually are well outside of it. Most of the time, you are at about 400ft MSL (350 ft AGL) when you come over I-880. When they give you straight in, you usually keep it to over 2000 (sometimes cheat it to 1500) over Downtown. When I was flying a lot more, I often heard advisories of unlighted construction cranes as high as almost 400 within a mile of the airport. Basically, no one flies below 500 ft AGL unless they have just taken off or are landing in the next 10-20 seconds, or are having troubles. The parking garage and likely the blast fence are higher than a flyover ramp would have to be and they are on the airport property. An I-880/US-101 interchange improvement may not get built in time to matter, for a lot of reasons, but the airport isn't one of them.
Thanks for the benefit of your experience!
Quote from: kkt on October 31, 2020, 09:53:10 AM
The 1 to 2 story light industrial park adjacent to the interchange doesn't seem like that much of a problem. This is not homes or landmark structures that people have fallen in love with. A good buyout offer, relocation expenses, and a generous timeline for relocation should be sufficient. Same for the other three sides, really, the car- and truck-oriented businesses there should be possible to relocate. The railroad would be a problem to move, but it's 1600 feet from the center of the interchange so it seems like it should be possible to rebuild the interchange while leaving it in place.
The adjacent interchanges along both I-880 and US 101 are closer than would be ideal.
Quote from: michravera on October 31, 2020, 04:30:57 AM
As someone who has landed, gone around, aborted landings, and done a large number of touch-and-go and stop-and-go landings and missed approaches on both runway 30R/12L and a few on 30L/12R, I can tell you that I-880 and US-101 doesn't even enter into the calculation of anything that you do at SJC. When you abort a landing and either go around or go missed, the first thing that you do is to fly the runway heading for some distance (usually until you are basically over the Bay on the 30 runways and until you have passed Downtown on the 12 runways) before you start a turn. About the only thing that the I-880/US-101 interchange is any good for is a reference point to use for your (really) tight traffic pattern (which is 1000 ft MSL or about 950 ft AGL) and, even then, you usually are well outside of it. Most of the time, you are at about 400ft MSL (350 ft AGL) when you come over I-880. When they give you straight in, you usually keep it to over 2000 (sometimes cheat it to 1500) over Downtown. When I was flying a lot more, I often heard advisories of unlighted construction cranes as high as almost 400 within a mile of the airport. Basically, no one flies below 500 ft AGL unless they have just taken off or are landing in the next 10-20 seconds, or are having troubles. The parking garage and likely the blast fence are higher than a flyover ramp would have to be and they are on the airport property. An I-880/US-101 interchange improvement may not get built in time to matter, for a lot of reasons, but the airport isn't one of them.
Thanks for the benefit of your experience!
The Koll group might have something to say about their industrial park being encroached upon; as I stated earler, they own a lot of properties in Santa Clara County and are quite well-connected. But be that as it may -- although Caltrans doesn't usually entertain such things, a turbine-type interchange (
a la Oak Park/US 50/CA 99/Biz 80) might well fit reasonably well into the space provided; while the turbine ramps may not be truly high-speed (guessing 35mph as average), it certainly would be an improvement over what's on the ground now!
US-101 N to I-880 S should be closed to improve weaving. Mainline traffic could use I-280 N to get to the freeway.
That leaves US-101 S to I-880 N. Not sure what could be done. Maybe a loop ramp from CA-87 S to I-880 N? That might not be possible because of the river.
Ramp statistics from CalTrans. The most recent are 2010. They released the spreadsheet in 2018 but many many ramps were not measured including the US 101-I-880 ones. These are AADTs (no peak hour statistics for ramps).
101 NB to 880 NB ... 23,900
101 NB on from 880 NB ... 9,000
101 NB to 880 SB ... 9,100
101 SB to 880 SB ... 7,900
101 SB on from 880 SB ... 23,300
101 SB to 880 NB ... 4,800
101 SB on from 880 NB ... 10,600
Quote from: sparker on October 31, 2020, 04:39:27 PM
Quote from: kkt on October 31, 2020, 09:53:10 AM
The 1 to 2 story light industrial park adjacent to the interchange doesn't seem like that much of a problem. This is not homes or landmark structures that people have fallen in love with. A good buyout offer, relocation expenses, and a generous timeline for relocation should be sufficient. Same for the other three sides, really, the car- and truck-oriented businesses there should be possible to relocate. The railroad would be a problem to move, but it's 1600 feet from the center of the interchange so it seems like it should be possible to rebuild the interchange while leaving it in place.
The adjacent interchanges along both I-880 and US 101 are closer than would be ideal.
Quote from: michravera on October 31, 2020, 04:30:57 AM
As someone who has landed, gone around, aborted landings, and done a large number of touch-and-go and stop-and-go landings and missed approaches on both runway 30R/12L and a few on 30L/12R, I can tell you that I-880 and US-101 doesn't even enter into the calculation of anything that you do at SJC. When you abort a landing and either go around or go missed, the first thing that you do is to fly the runway heading for some distance (usually until you are basically over the Bay on the 30 runways and until you have passed Downtown on the 12 runways) before you start a turn. About the only thing that the I-880/US-101 interchange is any good for is a reference point to use for your (really) tight traffic pattern (which is 1000 ft MSL or about 950 ft AGL) and, even then, you usually are well outside of it. Most of the time, you are at about 400ft MSL (350 ft AGL) when you come over I-880. When they give you straight in, you usually keep it to over 2000 (sometimes cheat it to 1500) over Downtown. When I was flying a lot more, I often heard advisories of unlighted construction cranes as high as almost 400 within a mile of the airport. Basically, no one flies below 500 ft AGL unless they have just taken off or are landing in the next 10-20 seconds, or are having troubles. The parking garage and likely the blast fence are higher than a flyover ramp would have to be and they are on the airport property. An I-880/US-101 interchange improvement may not get built in time to matter, for a lot of reasons, but the airport isn't one of them.
Thanks for the benefit of your experience!
The Koll group might have something to say about their industrial park being encroached upon; as I stated earler, they own a lot of properties in Santa Clara County and are quite well-connected. But be that as it may -- although Caltrans doesn't usually entertain such things, a turbine-type interchange (a la Oak Park/US 50/CA 99/Biz 80) might well fit reasonably well into the space provided; while the turbine ramps may not be truly high-speed (guessing 35mph as average), it certainly would be an improvement over what's on the ground now!
Maybe Koll would be unhappy with it, but I would think to a large property owner it's just another investment, and they don't feel any more personal about it than a bunch of stocks or bonds. If they want that invested in an industrial park, they could buy or start another one.
^^^^^^^^^^^
The Koll park is actually a very nice, park-like complex (as I stated previously, I almost moved my business there in 1986, a few years after it opened); it would not only be the Koll company that would likely object to any significant encroachment but the tenants of the offices and warehouses in the park. Approaching the issue as if it, or any particular property, is no more than a fungible entity doesn't take into consideration the commercial rental pricing in the South Bay; suggesting that an eminent domain settlement for taking a sizeable portion of the property would be considered appropriate compensation for both the relocation costs of the tenants plus the diminished recurring rental/lease revenue accruing to the property owners would likely be a non-starter in this case. If any plans for revamping of the 101/880 interchange involve substantial encroachment on that office park, expect to see litigation in short order (unless Caltrans is prepared to "back up the Brinks truck" to Koll and the affected lessees). But all this is speculation -- there are no plans for any interchange revision in the works presently; the current situation, substandard as it is, will probably stick around for at least the next decade.
And this is why I said flyovers would be prohibitively expensive. It's not the cost of the structures themselves but the cost of the right of way necessary to accommodate them and construct everything to modern standards.
A shame that so many freeway to freeway interchanges were designed as cloverleafs when stacks do a much better job. Of course, there is no feasible way to upgrade this 880/101 now, but I do wonder why this was chosen in the first place. The 101/110 stack interchange in L.A. (even with its own issues) is a far better design than a cloverleaf. The 101/110 interchange is older than this interchange so Caltrans could have put in a similar stack into the 101/880 interchange when it was first created.
Quote from: mrsman on November 01, 2020, 04:14:12 PM
A shame that so many freeway to freeway interchanges were designed as cloverleafs when stacks do a much better job. Of course, there is no feasible way to upgrade this 880/101 now, but I do wonder why this was chosen in the first place. The 101/110 stack interchange in L.A. (even with its own issues) is a far better design than a cloverleaf. The 101/110 interchange is older than this interchange so Caltrans could have put in a similar stack into the 101/880 interchange when it was first created.
Maybe it's because the area used to be rural so the planners put the cheapest freeway-to-freeway interchange there, and didn't expect the explosive traffic and population growth decades later that would overwhelm the design. See also: I-680 and I-580 interchange.
Yes, the 101-880 interchange was contracted in 1960 when San Jose was a modest farm town.
See the photo-essay by Max Rockatansky at https://www.gribblenation.org/2018/01/california-state-route-17.html
with the relevant scan from California Highways and Public Works.
^^^
Man, I worked over that article twice and somehow I don't even remember a lot of what I wrote. Thankfully those CHPW volumes were pretty exacting in terms of finding specific dates of freeway openings.
Quote from: TheStranger on October 30, 2020, 11:11:46 AM
Quote from: kkt on October 29, 2020, 11:01:14 PM
US 101 - CA 92 was one terrible cloverleaf that's been made much better. Much of the work was done in the early 1980s, if I remember right.
Looking at HistoricAerials, the work to upgrade that interchange to add the two flyovers (SB 101 to EB 92, NB 101 to WB 92) occurred sometime between 1984 and 1988. There are stubs for flyovers that were never built (EB 92 to NB 101 and WB 92 to SB 101) during that project.
That interchange seemed to be another one that was partially constructed on the assumption of future improvements occurring (which fortunately did for the most part). I remember in the late 70's/early 80's coming back from SFO to the east bay on 92 the s/b 101 to e/b 92 cloverleaf was constructed on wooden pilings, like a fishing pier or railroad trestle - haven't seen that one anywhere else. The 92 mainline overpass over 101 was built in the typical early 70's design and this funky cloverleaf tied into it but, perhaps like the infamous "Stonehenge" 101/680/280 interchange that sat unfinished for many years, they didn't have the funds to complete it so that was the quick fix. It was finally replaced with a flyover when the rest of 92 was improved in that area, including bypassing that solo signal at Norfolk St.
The US 101/CA 92 interchange was completed and open to traffic by December 1988. I was at the Stereophile magazine audio show held at the now-gone Dunfey Hotel facing the northwest quadrant of that interchange in late April 1989; they were just doing the interchange landscaping (pretty much just sowing grass) at that time. The original cloverleaf was simply a street interchange expanded into a rudimentary freeway-to-freeway facility; the CA 92 overpass wasn't even divided until the freeway east through Foster City to the bridge landing was widened in 1973-74.
Quote from: CtrlAltDel on October 30, 2020, 08:23:04 PM
I admit I'm not an expert on this, but I don't see how the I-880/US-101 interchange could affect the operations of the airport in any way. Assuming that the interchange is the red circle and the runways are the green lines, and I just can't see how a plane could swoop around from that interchange to line up with either of those two runways.
(https://i.imgur.com/wdTyWnz.png)
It may seem silly, but the FAA does mandate maximum structure heights on all sides of a runway, though they are much less strict on the sides than off the ends of course. As I understand it, the reason for this is for visibility when approaching at an angle as well as preventing interference with instruments.
That being said, I know for a fact that you can fit flyover ramps at 880/101 there within the height limits because a couple students at my university designed a stack interchange replacement for their senior project. And the comments others have made about cost and Right of Way/eminent domain are right on the mark, they did indeed find that significant property would be needed and the cost would thus be prohibitive. (Not to mention very limited merge areas due to close spaced interchanges all around.)
What a good project! Was that at a Bay Area college?
Quote from: kkt on November 15, 2020, 09:08:25 AM
What a good project! Was that at a Bay Area college?
Yup! Santa Clara University, which is just in the bottom left of the aerial CtrlAltDel posted :P