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Car Forum / Driving, Maintenance, Tuning / Driving / December 2005Orange County & Riverside Working to Double Deck CA-91, Add Cleveland Tunnel
http://www.nctimes.com/articles/2005/11/19/news/californian/22_03_3611_18_05.txt Double-deck freeway, forest route OK'd as part of plan to ease commute to Orange County By: DAVE DOWNEY - Staff Writer ORANGE ---- A freeway through the forest and a double-decked Highway 91 are the highlights of a $10 billion plan adopted Friday for improving travel between Riverside and Orange counties. A regional transportation panel decided to recommend building those new roads, and add a few lanes to the 91, to accommodate the roughly 450,000 cars forecast to travel daily between the counties by 2030. The panel didn't specify whether the forest freeway, extending from Interstate 15 and Cajalco Road to Irvine, would go either in a long, continuous tunnel under the Santa Ana Mountains or a series of short tunnels interspersed with overland highway sections. It would not be built entirely above ground through the Cleveland National Forest, however. If transportation officials wanted to put all traffic on Highway 91, they would need to widen it to 22 lanes, Rahimian said. Today, the freeway has 10 lanes at Interstate 15 and 14 lanes in Orange County. The highway runs through a heavily urbanized area of Corona and Anaheim Hills, and there is little room for expansion. The $10 billion preferred plan does call for some widening on Highway 91 in Riverside County, to match the number in Orange County, Rahimian said. With those improvements in place, officials could accommodate the forecast growth either by constructing a six-lane elevated highway over the 91, or punching a six-lane freeway through the forest. Or, he said, officials also could choose to build both an elevated highway in Corona and a road across the forest. In that case, each would require four lanes. Cost projections include $6 billion for the forest-tunnel highway. The Corona elevated highway's price tag is pegged at $2.7 billion. [The] second deck would partially cover the 91 and would run between I-15 and the Highway 241 toll road in Orange County. It would empty directly onto the 241, where tolls might be scrapped or substantially reduced to lure more commuters. ---- More at link, that was quickly cropped to provide the most roadgeeky info. Dave >http://www.nctimes.com/articles/2005/11/19/news/californian/22_03_3611_18_05.txt > >Double-deck freeway, forest route OK'd as part of plan to ease commute >to Orange County >The $10 billion preferred plan does call for some widening on Highway >91 in Riverside County, to match the number in Orange County, Rahimian [quoted text clipped - 5 lines] >highway in Corona and a road across the forest. In that case, each >would require four lanes. >[The] second deck would partially cover the 91 and would run between >I-15 and the Highway 241 toll road in Orange County. It would empty >directly onto the 241, where tolls might be scrapped or substantially >reduced to lure more commuters. How quickly we forget what happened to the Nimitz Freeway in Oakland on October 17, 1989... Sure, sure, we arrogantly believe that our engineering skills are better now, and that we can build an "earthquake-proof" double-decker freeway. But we also thought that the Titanic was unsinkable... If this deathtrap ever gets built, it will just be one more reason to be glad that I live and work in OC and don't have to drive on the 91. > >http://www.nctimes.com/articles/2005/11/19/news/californian/22_03_3611_18_05.txt > > [quoted text clipped - 25 lines] > If this deathtrap ever gets built, it will just be one more reason to > be glad that I live and work in OC and don't have to drive on the 91. It could happen, and the new San Diego Trolley structures could fall on I-8, or an interchange could collapse on me, or a tsunami could wash me away, or a gas main could blow up under me, or an airplane could crash on my house. They can mitigate the risk. The Nimitz was a very old and poorly designed structure. Maybe a collapse will happen, but I believe the risk can be minimized enough that it wouldn't be my biggest concern in a major earthquake. Dave >It could happen, and the new San Diego Trolley structures could fall on >I-8 What trolley structures? I have driven I-8 through SD regularly for the last 5 years, and I don't recall seeing any sort of Nimitz-style double-decker arrangement with the trolley tracks suspended above the freeway. Where is this double-decker structure located? >or an interchange could collapse on me There's a BIG difference between an overpass that's, what, 100' wide, and a double-decker freeway that goes on for MILES. However, YOU can go right ahead and feel free to drive underneath it. > >It could happen, and the new San Diego Trolley structures could fall on > >I-8 [quoted text clipped - 5 lines] > with the trolley tracks suspended above the freeway. Where is this > double-decker structure located? Just west of the new college station between I-15 and College Ave, mostly built since 2003, just recently completed. It's not quite Nimitz style, but it's a big chunk O' concrete above a freeway. That or ride the trolley through the tunnel under SDSU, same difference. > >or an interchange could collapse on me > > There's a BIG difference between an overpass that's, what, 100' wide, > and a double-decker freeway that goes on for MILES. How about stacked interchanges, or the cut-n-cover tunnels on CA-15 south of I-8? The parts of the Nimitz that collapsed are comparable to the amount of concrete I drive under in about 20 minutes around here. According to http://home.pacbell.net/hywaymn/Cypress_Viaduct_Freeway.html 42 people died. If this is wrong, please correct me, but this tunnel-phobic fear (you like that one?) is based on the collapse of a tiny part of a 35+ year old section of freeway effecting a tiny fraction of the daily users? That freeway was completed 48 years ago. Do you really think we haven't learned enough to keep almost all of a freeway from falling now? If not, watch out for the I-5 HOV lanes in Teh OC. Never drive in Mexico, most of their bridges don't look like they'd survive over a 4 or 5. Oh, and make sure you don't leave any doorways. > However, YOU can go right ahead and feel free to drive underneath it. Not a problem, if I'm going to get crushed by a freeway, I'm going to get crushed by a freeway. It's still better than a heart attack on the crapper cause I pushed too hard, which is much more likely. Dave >> >It could happen, and the new San Diego Trolley structures could fall on >> >I-8 [quoted text clipped - 9 lines] >mostly built since 2003, just recently completed. It's not quite >Nimitz style, but it's a big chunk O' concrete above a freeway. There are gigantic flyovers that connect I-805 with I-8, but, once again, this is basically an overpass that's as wide as the road itself; the chances of this little section falling on you when you're driving on I-8 are pretty small. >That or ride the trolley through the tunnel under SDSU, same >difference. Yeah, it sounds like the chances of those trolley tracks falling on top of me as I drive past SDSU on I-8 are vanishingly small. ;) >According to >http://home.pacbell.net/hywaymn/Cypress_Viaduct_Freeway.html 42 people >died. If this is wrong, please correct me, but this tunnel-phobic fear >(you like that one?) is based on the collapse of a tiny part of a 35+ >year old section of freeway effecting a tiny fraction of the daily >users? That's one way to look at it. Another way is to notice that this represents the single largest concentration of deaths in the entire area affected by the Loma Preieta event - including Santa Cruz, which was much closer to the epicenter of the quake. >That freeway was completed 48 years ago. Do you really think we >haven't learned enough to keep almost all of a freeway from falling >now? Yes. It is the height of arrogance to think that anything built by man is "earthquake-proof." >Never drive in Mexico I'll never even GO to Mexico, and it's not because of the earthquakes. ;) >> However, YOU can go right ahead and feel free to drive underneath it. > >Not a problem, if I'm going to get crushed by a freeway, I'm going to >get crushed by a freeway. Do you ever wear a raincoat or use an umbrella? After all, if you're going to get wet, you're going to get wet. Do you ever go to the dentist? After all, if you're going to lose a tooth, you're going to lose a tooth. Do you go to the doctor? Do you have insurance? Do you do ANYTHING to try to take control of your own destiny, or do you let life wash over you like waves on a beach? > Do you go to the doctor? Do you have insurance? Do you do ANYTHING to > try to take control of your own destiny, or do you let life wash over > you like waves on a beach? I take reasonable precautions and don't let the "what ifs..." of natural disasters control my life. I keep water in my house, in case an earthquake happens, I have a flashlight, radio, etc, but I'm also willing to leave my house and not have that stuff with me for hours or days at a time. The decreasingly small chance of a newly built structure collapsing in a quake is something I can live with, a quake is more likely to kill me a lot of other ways anyway. If you want to avoid double-decked freeways it's just less traffic on them for me. Dave > Oh, and make sure you don't leave any doorways. But stay out of the doorways during the quake, the door will hit you! :-) I've wondered about transition roads during a quake - somehow I see those tall structures giving a good toss to vehicles at speed. They're just now building a train overpass on the 78. jg -- @home.com is bogus. http://automobilemag.com/photo_gallery/0511_transylvania/ > > Oh, and make sure you don't leave any doorways. > [quoted text clipped - 5 lines] > > They're just now building a train overpass on the 78. You mean the Sprinter overpass? I got so excited, thinking it was going to be a useful overpass the first time I saw it. Then I found out it was just the SM Loop. D'oh. Dave Scott, The Nimitz was built during the 1950's, when there was much less understanding of earthquakes. It was obviously not built to withstand a 7.0+ earthquake. There's structures that carry 2-directional traffic above ground-level traffic in So Cal. Think of the 4 lane viaduct that carries carpoolers above I-110 SOV's (built in the early 90's), the I-5 HOV viaduct that links to the 55 freeway (built in the late 90's/early 2000's); not to mention other flyover ramps that have been built throughout California over the past 10 years, with strict engineering requirements. I would feel safer on one of these carpool ramps in an earthquake, than along some city street in San Francisco, any day. -Brent > >http://www.nctimes.com/articles/2005/11/19/news/californian/22_03_3611_18_05.txt > > [quoted text clipped - 25 lines] > If this deathtrap ever gets built, it will just be one more reason to > be glad that I live and work in OC and don't have to drive on the 91. >The Nimitz was built during the 1950's, when there was much less >understanding of earthquakes. It was obviously not built to withstand [quoted text clipped - 4 lines] >above I-110 SOV's (built in the early 90's), the I-5 HOV viaduct that >links to the 55 freeway (built in the late 90's/early 2000's) I'm familiar with the HOV flyovers at the 5-55 interchange in Santa Ana. They are only one lane wide, and run mostly *between* the two halves of the freeway. The same is true of the HOV flyovers in the expanded El Toro Y. This is nothing like what is being proposed for the 91. >>The Nimitz was built during the 1950's, when there was much less >>understanding of earthquakes. It was obviously not built to withstand [quoted text clipped - 10 lines] > expanded El Toro Y. This is nothing like what is being proposed for > the 91. Exactly. If those HOV elevated ramps fell, they'd most likely fall to one side or another. Which would cause major problems, but it's nothing like the total failure of the Nimitz in West Oakland, or such as is being proposed for CA-91. There are parts of the I-5 Express Lanes in downtown Seattle that are built underneath the mainline lanes, and all of them are constructed as a viaduct alongside Capitol Hill above the downtown core. That's probably far less safe than the HOV lanes on I-5/CA-55 or I-110, but those Express Lanes here in Seattle have weathered the decades just fine so far.  SignatureRobert I. Cruickshank roadgeek, historian, progressive > >>The Nimitz was built during the 1950's, when there was much less > >>understanding of earthquakes. It was obviously not built to withstand [quoted text clipped - 26 lines] > Robert I. Cruickshank > roadgeek, historian, progressive This is only going to be 4-6 elevated lanes, much like elevated HOV lanes. From the sound of things these will be HOT lanes to connect directly into the OC toll roads, and the current HOT lanes will connect into CA-91 west of CA-241. These aren't going to be like the Nimitz structure, and the only other option would either remove over 500 buildings which nobody seems willing to accept, or require taking the rail tracks north of CA-91 which is logistically a bad idea. They could just cut more tunnels through/under the mountain, but that's a whole new set of problems. Dave I guess theoretically any bridge or viaduct can fail. But the problem with the Nimitz (and the Embarcadero that came close to failing) was that the upper deck tied into the lower deck. The more modern "double decking" is achieved by independent structures of differing heights... the upper decks have columns that go all the way to the ground, independently of the lower decks. So the upper deck is just a very tall structure, no different than a flyover. > I guess theoretically any bridge or viaduct can fail. But the problem > with the Nimitz (and the Embarcadero that came close to failing) was [quoted text clipped - 3 lines] > independently of the lower decks. So the upper deck is just a very tall > structure, no different than a flyover. I think that would be worse...taller piers, in theory, would be more prone to shaking during an earthquake (longer moment arm). The problem is the fixed end of the pier, in the ground..I guess you could dampen each pier where it connects the ground. I think tying the two strutcures together in the same piers would be more rigid, though. Didn't the Nimitiz fail moreso b/c of the ground conditions there? IIRC, some large areas in the Bay Area are subject to liquifaction during an earthquake, such as the reclaimed lands from the bay. An elevated freeway in Kobe Japan failed due to liquifaction > > I guess theoretically any bridge or viaduct can fail. But the problem > > with the Nimitz (and the Embarcadero that came close to failing) was [quoted text clipped - 9 lines] > each pier where it connects the ground. I think tying the two > strutcures together in the same piers would be more rigid, though. Tall bridge piers can be built to high seismic standards. > Didn't the Nimitiz fail moreso b/c of the ground conditions there? > IIRC, some large areas in the Bay Area are subject to liquifaction > during an earthquake, such as the reclaimed lands from the bay. An > elevated freeway in Kobe Japan failed due to liquifaction The 1995 Great Hanshin Earthquake (M=6.9), commonly referred to as the Kobe earthquake, more than 5,500 were killed and over 26,000 injured. The economic loss has been estimated at about $US 200 billion. The Loma Prieta earthquake occurred on October 17, 1989 in the greater San Francisco Bay Area in California and measured 7.1 on the Richter magnitude scale (6.9 on the Moment magnitude scale). There were at least 66 deaths and 3,757 injuries as a result of this earthquake. The highest concentration of fatalities, 42, occurred in the collapse of the Cypress structure on the Nimitz Freeway (Interstate 880), where a double-decker portion of the freeway collapsed, crushing the cars on the lower deck. The quake also caused an estimated $6 billion in property damage, the costliest natural disaster in U.S. history at the time. SignatureScott M. Kozel Highway and Transportation History Websites Virginia/Maryland/Washington, D.C. http://www.roadstothefuture.com Philadelphia and Delaware Valley http://www.pennways.com I'm way out of my depth here, but I think I've seen models of interesting oscillations that can develop when the lower and upper decks get out of phase in their shaking. Also note that despite the age of the structure (and its design standards) ONLY the upper deck failed. I also know you don't want things too rigid... Of course, tall piers have failed TWICE at the 5/14 interchange; both times rebuilt to allegedly more stringent standards. Though there must be something to those standards, seismic retrofitting ate up a huge amount of CA's highway budget in the 90s. Whatever the ground conditions of the Nimitz, I doubt the ground conditions are any better in its new location (which is closer to the Bay). But it's built completely differently. A funny thing for a Californian is to drive through much of the rest of the country where the piers look like matchsticks compared to our structures. > I'm way out of my depth here, but I think I've seen models of > interesting oscillations that can develop when the lower and upper [quoted text clipped - 14 lines] > the country where the piers look like matchsticks compared to our > structures. yeah, our Seismic design for bridges here in the Midwest (OH) consists a raised block of concrete next to the beam seat to keep the beams from sliding off the pier. > > I'm way out of my depth here, but I think I've seen models of > > interesting oscillations that can develop when the lower and upper [quoted text clipped - 18 lines] > raised block of concrete next to the beam seat to keep the beams from > sliding off the pier. How quickly people have forgotten the New Madrid quake... See also http://hsv.com/genlintr/newmadrd/ if you're not familiar. The areas marked 5 and up would face probable damage, and 4+ would at least be at risk given the lack of preparedness for a quake like this. Dave >>>I'm way out of my depth here, but I think I've seen models of >>>interesting oscillations that can develop when the lower and upper [quoted text clipped - 26 lines] > > Dave Actually, New Madrid was *five* quakes, all of which reached intensity X or greater. > >>>I'm way out of my depth here, but I think I've seen models of > >>>interesting oscillations that can develop when the lower and upper [quoted text clipped - 29 lines] > Actually, New Madrid was *five* quakes, all of which reached > intensity X or greater. Yep, I've heard the set of four called the New Madrid Quakes, and the final one in the series that destroyed the town of New Madrid on 2-7-1812 I've heard called the New Madrid Quake. I could be wrong though, since I only heard there was 4 quakes in the series. Dave >>>>>I'm way out of my depth here, but I think I've seen models of >>>>>interesting oscillations that can develop when the lower and upper [quoted text clipped - 38 lines] > > Dave They don't know 100% for sure, but the first series included three in succession. There were single major quakes a few weeks later, and the current belief is that the total was 5. > I'm way out of my depth here, but I think I've seen models of > interesting oscillations that can develop when the lower and upper [quoted text clipped - 14 lines] > the country where the piers look like matchsticks compared to our > structures. Funny? I don't think so. I hate driving on those things. Especially when I think of this big quake here, and that big quake there, and ... >>I guess theoretically any bridge or viaduct can fail. But the problem >>with the Nimitz (and the Embarcadero that came close to failing) was [quoted text clipped - 14 lines] > during an earthquake, such as the reclaimed lands from the bay. An > elevated freeway in Kobe Japan failed due to liquifaction The failure to I-880 on Oakland was mostly a function of the design. The structure was far too rigid, and the rebar in the concrete lacked horizontal bracing. The ground in that area is harder alluvium, which is similar to most of the Bay Area, and doesn't liquefy like the softer landfill as you would find in SF's Marina district. > http://www.nctimes.com/articles/2005/11/19/news/californian/22_03_3611_18_05.txt > [quoted text clipped - 17 lines] > built entirely above ground through the Cleveland National Forest, > however. The main issues facing this - aside from funding - are seismic. Not so much a concern that a tunnel might collapse in an earthquake, but uncertainty about where the fault lines are in the Santa Anas, in case the tunnel were to shift. As long as a funding source can be found, I'm in favor of it... SignatureRobert I. Cruickshank roadgeek, historian, progressive > > http://www.nctimes.com/articles/2005/11/19/news/californian/22_03_3611_18_05.txt > > [quoted text clipped - 22 lines] > uncertainty about where the fault lines are in the Santa Anas, in case > the tunnel were to shift. I think that's part of the reason for them leaving the option of a series of shorter tunnels. I'm not certain, but I think it was in a previous article in the NC Times. The environmental studies, given the cost estimates, probably will take a whole new look at the seismic issues. Hopefully a side effect of this project can be a better understanding of the faults in SoCal. > As long as a funding source can be found, I'm in favor of it... It will almost definitely have to be a toll road, but given the use of the 91 Express lanes, it's not doubtful that it could happen with a price of as little as $3 or $4 per use, which would be almost the same as, if not less than, the gas saved by using it. Considering Riverside County has a cross-county expressway/freeway in the planning stages along Cajalco Rd also, and the current Orange County toll roads it seems like it would be a very accessable, and thus profitable, route. Both counties already have or plan to have significant investments in their F&E systems to work with this route, and it will help grow the tax base in both regions also. Funding will be found. Looking at the Cajalco Rd interchange and the space around it makes me wonder how they'd build that end also. I'm sure this project will significantly effect the growth patterns of that area also, but it's just another necessary evil caused by the current housing issues and growth of the region. Dave >The main issues facing this - aside from funding - are seismic. Not so >much a concern that a tunnel might collapse in an earthquake, but >uncertainty about where the fault lines are in the Santa Anas, in case >the tunnel were to shift. That's another excellent point. The maps published in the OC Register a few weeks ago show very clearly that at least one known (and how many UNknown?) faults will be crossed by the tunnels. http://quake.wr.usgs.gov/info/1906/historical.html The above page shows some fences across the San Andreas that were offset during the 1906 SF quake. Can you imagine what would happen if one of the faults being crossed by the tunnels were to shift like that? >>The main issues facing this - aside from funding - are seismic. Not so >>much a concern that a tunnel might collapse in an earthquake, but [quoted text clipped - 13 lines] > one of the faults being crossed by the tunnels were to shift like > that? You are safer in a properly constructed tunnel than on an overpass, bridge or elevated section during a quake. |
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