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Are heavy vehicles destroying our bridges?

steverstever Guest Posts: 52,454
Tidester was wondering wonder whether anyone would like to speculate on whether today's heavier vehicles may be contributing to more rapid deterioration of bridges and highways.

"This article says:

"... the average vehicle today simply weighs a lot more than it did then. In 1981, the average passenger vehicle weighed about 3,200 pounds. Today, thanks mostly to more SUVs and vans, the average vehicle weighs almost 4,100 pounds."

Surely, the engineers who designed the I-35 bridge in Minneapolis didn't anticipate such a load. Each traversal of a bridge by any vehicle has a microscopic effect proportional to its weight but that gets multiplied by 1 to 2 BILLION crossings over 40 years!"

I changed Tides' wording from vehicles to SUVs & trucks to make sure this new discussion got everyone's attention. :)
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Comments

  • grbeckgrbeck Member Posts: 2,358
    ...tractor trailers may be destroying our bridges.

    But I would doubt that SUVs make much difference, as bridges have always been built to withstand much heavier vehicles (UPS delivery trucks, tractor trailers that were smaller than the ones used today, but still much heavier than an SUV).

    Using 1981 as a starting point is not quite fair. The great downsizing was still underway. Most of our infrastructure was not built in the 1980s. If anything, I remember articles in the 1980s worrying that the new downsized cars would not be compatible with the design of our roads and bridges (features designed to route a typical 1960s full-size car back on the road could flip a smaller 1980s car). Most of our infrastructure was built using the 1960s full-size car as the standard.

    The bridge that collapsed in Minnesota, for example, was completed in the late 1960s.

    In the 1960s, Cadillacs and Lincolns topped out at over 5,000 pounds, and the biggest Buicks, Oldsmobiles and Chryslers weren't far behind. The most popular vehicles were the Chevrolet Biscayne/Bel Air/Impala/Caprice and Ford Galaxie/LTD, which were hardly feather weights.

    Heavy vehicles are hardly anything new.

    If anything, heavier use by all vehicles is probably contributing to the more rapid deterioration of bridges and highways. Traffic volumes keep going up, up, up.
  • iluvmysephia1iluvmysephia1 Member Posts: 7,704
    and this toll on bridges is affected by the fact that more 16 year-olds join our ranks as drivers every year than 85 year-olds that stop driving. Year after year after year the counts go up...that's bound to take a toll on bridge poundings.

    Being a Pacific Northwesterner originally I have watched the footage of the Tacoma Narrows Bridge's collapse 60-odd years ago. That was engineering error to not take in to account the harrowing winds of the Narrows. My Grandpa lived on the other side of the rebuilt Narrows Bridge in a little community called Gig Harbor. Truly a beautiful place and it's a pretty view down below from the rebuilt bridge as Dad would drive this way to get us to Grandma and Grandpa's house.

    2021 Kia Soul LX 6-speed stick

  • euphoniumeuphonium Member Posts: 3,425
    The bridge was a truss-type bridge, where the deck the traffic travels on is on top of the truss. It is a structural concept very similar to the bridge across the Columbia at Longview and those on I-5, both north and south of Longview. Except on those structures the bridge deck is connected to the bottom cord of the truss and the traffic travels through the structure. Placing the structure on the top cord of the truss allows easier cross-connection between the two main trusses of the bridge, making a lighter, but stronger structure. (The cords of a truss are the top and bottom members that form the outline of the truss.) Trusses generally use a series of triangles as the connection of three members in the shape of a triangle is a fairly stable structure.

    Problems with truss construction usually occurs at the joints where three or more members connect. Usually the connections are a series of plates used to make the connections using rivets (old construction), bolts (Most likely for the Minneapolis bridge) and welding (More modern construction) to connect the plates as they lap on the sides of the main structure members. This would be similar to joining two sheets of paper end to end, using scotch tape on each side to connect them. The paper would be the structure, the tape would be the side connecting plates. The problems with the truss connections is that there can be corrosion in between the plate and member that is not visible from looking at the connection as they inspect. This would require using test equipment of some kind - ultrasound for one. Welds can be inspected with x-rays, but this is expensive. Also micro-cracks can develop in the connecting plates or even in the main structure that can't be seen by the naked eye. These can be generated and enlarged by the passage of traffic.

    Looking at the sequence that shows the bridge collapsing, I got the feeling that the bottom cord was the item that failed. The bottom cord is in tension, which means it is being pulled apart. Top cords are in compression - if you try to pick up four books by pressing against the side of the books, instead of supporting from below, you are compressing the books to form a single unit. Compression failures are usually distorted. There was no major distortion until the structure hit the ground. Tensile failures will talk and make noise before they break, but the break is very sudden. With the normal traffic noise I doubt that anyone would have heard are recognized that a failure was about to happen.
  • wlbrown9wlbrown9 Member Posts: 867
    About 15 years ago, Arkansas/Mississippi/Tennessee still had 72,000 truck weight limits...everywhere else had gone up to 80,000 lbs. Much lobbying and predictions that keeping the low limits would hinder commerce. Eventually the truck industry was successful in getting the limits raised. That extra 8,000 might be rougher on the highway and bridge network than a couple hundred pounds on a passenger vehicle.

    Anyone know the history of (US Highway & Interstate) truck weight limits?
  • steverstever Guest Posts: 52,454
    There's some history in this link from Hendrickson USA. Some good diagrams there too about axle weight and the difference a heavy short truck makes vs a heavy long truck.

    And we've tweaked the title a little so we don't pick on Hummers too much - I trust we didn't lose anyone.
  • fezofezo Member Posts: 10,384
    What? Hummers aren't heavy vehicles? :P

    What really hurting our bridges, along with our roads, water systems and anything else in the infrastructure is the insane lack of maintenance. You can see the difference when you hit that rare piece of work that actually IS maintained well. The Golden Gate Bridge is one that amazes me. The thing is over 70 years old and looks like they just built it. There is always someone painting it.

    Over where I am I'm not sure of the reason but the difference between two of the bridges going for New Jersey to Philadelphia is striking. The Walt Whitman looks fine. The Ben Franklin looks like it is going to rust away. I don't get it.

    I suspect that roads and bridges that have to pay their own way do better even though I am loathe to give anyone any ideas about more tolls and the Ben Franklin example would certainly not back this up. I think of things like the Garden State Parkway, George Washington Bridge and the Whitestone Bridge.

    Meanwhile, practically new sections of Route 287 are falling apart and I shudder to think about the Tappan Zee - a truly beautiful structure that has been left to rot with a ton of traffic.
    2015 Mazda 6 Grand Touring, 2014 Mazda 3 Sport Hatchback, 1999 Mazda Miata 2004 Toyota Camry LE, 1999.
  • lemkolemko Member Posts: 15,261
    The Ben Franklin Bridge is also much older than the Walt Whitman. The Ben Franklin Bridge was built in 1926 and the Walt Whitman in 1957. Before the Ben Franklin Bridge, Philadelphians relied on ferry service to get to Camden, NJ.
  • fezofezo Member Posts: 10,384
    Good point, but I still wonder why they can't do basics like paint the Ben Franklin. Structurally it is a pretty bridge but it definitely needs work.

    They still had ferrys going across the Delaware into the 60s in Wilmington. I remember going across the bridge that is now there when they were still building the second span.
    2015 Mazda 6 Grand Touring, 2014 Mazda 3 Sport Hatchback, 1999 Mazda Miata 2004 Toyota Camry LE, 1999.
  • lemkolemko Member Posts: 15,261
    I believe a huge repainting project for the Ben Franklin is already in the works. I read that it costs something like $40 million to do the job and is the job of the Port Authority.

    Of the other major bridges - the Betsy Ross Bridge opened for traffic in 1976, the Commodore Barry Bridge in 1974, and the Tacony-Palmyra bridge in 1929.
  • tidestertidester Member Posts: 10,059
    Most of our infrastructure was built using the 1960s full-size car as the standard.

    The 1980 date just happened to be the date used in that particular article. As for the 60s, even though there were some monster cars in terms of weight, the average weight of passenger cars was just over 3,000 pounds. In fact, the average weight of passenger cars has decreased over that period but proportionally far more people are driving SUVs and pickups than the engineers ever imagined.

    tidester, host
    SUVs and Smart Shopper
  • fezofezo Member Posts: 10,384
    Whoa! Now that and the Burlington-Bristol Bridge are real adventures!
    2015 Mazda 6 Grand Touring, 2014 Mazda 3 Sport Hatchback, 1999 Mazda Miata 2004 Toyota Camry LE, 1999.
  • kernickkernick Member Posts: 4,072
    I would prefer a bridge that lasted a long time and didn't need much maintenance.

    Have you ever noticed that ancient structures lasted for hundreds or even thousands of years. Why was that? What is the lifespan of our modern structures? I know in Boston the elevated highway was 40-50 years old and crumbling. It takes 15 years and $20B to replace it. How long are the new tunnels and bridges going to last? I hope not just 40 years!

    Maybe we should question whether regular steel and concrete are the best building materials. Replace their use where possible. Once steel is delivered to a building site, and put at the site, you start getting corrosion even before the steel is up. That doesn't bode well for long-life.

    But I believe a lot of the construction attitude in this country is that we'll just replace it and that creates a lot of jobs, and chances for corruption to skim from the projects.

    I'm afraid we have too much of a throw-away philosophy, that is now a paradigm of policy.
  • cooterbfdcooterbfd Member Posts: 2,770
    This would require using test equipment of some kind - ultrasound for one. Welds can be inspected with x-rays, but this is expensive.

    Well, where are our gasoline taxes and tolls going??? To Iraq??? I know here in RI, where we pay some of the largest STATE gas tax in the country, it is SUPPOSED to fund road repairs. Most of it ends up in our general fund, to be spent elsewhere. If the feds and other states do this, it's not fair. This money should be spent on repairs, new infrastructure, and public transportation ONLY!!!!
  • kernickkernick Member Posts: 4,072
    I just paid $300 auto registration tax to my city yesterday. I also did the state registration, which is what pays for the plates and paperwork. The city tax - by far the larger, goes to the general fund.
  • fezofezo Member Posts: 10,384
    "But I believe a lot of the construction attitude in this country is that we'll just replace it and that creates a lot of jobs, and chances for corruption to skim from the projects."

    Precisely so. Big shiny capital projects are much sexier to show off to the folks at home than periodic inspection and maintenance would be. I mean which do you notice more, a big building project of a few guys painting?

    Of course a couple of the most impressive bridges are the ones that ARE older and maintained. I already used the Golden Gate as an example. The George Washington is another.
    2015 Mazda 6 Grand Touring, 2014 Mazda 3 Sport Hatchback, 1999 Mazda Miata 2004 Toyota Camry LE, 1999.
  • roadburnerroadburner Member Posts: 17,312
    I blame Rosie O'Donnell and Queen Latifah- and whoever keeps them supplied with Twinkies.

    Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive

  • fezofezo Member Posts: 10,384
    Good point. I knew there was a way to blame this on Rosie. I Queen Latifah is a harder one for me. Rutgers alum....
    2015 Mazda 6 Grand Touring, 2014 Mazda 3 Sport Hatchback, 1999 Mazda Miata 2004 Toyota Camry LE, 1999.
  • 0patience0patience Member Posts: 1,712
    euphonium,
    You must be in my neck of the woods to be talking about the Longview (Lewis & Clark) bridge.

    I was surprised to hear that 7 years ago, that bridge was inspected and they didn't do anything since then.
    I may have heard it wrong on the radio, but that seemed odd.

    Oregon is constantly inspecting the bridges.
    They have trucks with special cranes that swing down over the side and the inspectors can view the underside of the bridge and inspect it.
  • gagricegagrice Member Posts: 31,450
    I'm afraid we have too much of a throw-away philosophy, that is now a paradigm of policy

    I think that is exactly correct. It makes no difference if it is a car, computer or bridge. I watch the strip malls going up in So. CA. They are pathetic examples of horrible construction. They will be gone in 20 years for sure. Wonder if the pyramids were built like the I35 bridge over the Mississippi river. All we know how to build is for the short term. I wanted to build an adobe home. I see adobe homes in Mexico that are 300-400 years old and still standing. No that is not compatible with current building standards.

    Yeah, the city wants a house that falls apart in 20 years so they get more taxes on the rebuild.

    The authorities reviewed the safety record of the bridge, which had been designated “structurally deficient” as early as 1990. More than 70,000 bridges across the country are rated structurally deficient like the I-35W bridge, and engineers estimate repairing them all would take at least a generation and cost more than $188 billion.

    159,000.
    That's the approximate number of bridges that are either "deficient" or "obsolete," according to the American Society of Civil Engineers.

    159,000.

    That's more than one in four.

    Approximately 73,000 of them are "structurally deficient" - like the bridge in Minneapolis - while 80,000 others are "functionally obsolete." That means they're carrying more traffic than they were designed to carry.

    Not scary enough? Then try this quote on for size: "I think we're going to see bridges collapse, and we do on a regular basis," said Kent Harries of the University of Pittsburgh's School of Engineering.


    London bridges falling down
  • toro52toro52 Member Posts: 1
    My last trip to Italy I drove over a bridge the Romans built 2000 years ago..maybe the engineers should look at their blueprints..Toro52
  • gagricegagrice Member Posts: 31,450
    As smart as we think we are, we could learn from engineers that were around 5000 years ago. I am sure many of our bridges were built by low bid contractors and brother in law deals.

    It reminds me of a question posed to old Mayor Daley. Why did your son in law get the contract? Mayor Daley popped right back with "What Kind of Man Does not Look out for His Own Kin".

    So we have a lot of bridges built with substandard materials and maybe unskilled labor.
  • cooterbfdcooterbfd Member Posts: 2,770
    maybe unskilled labor

    I don't know about that up here in the northeast. Most, if not all jobs are union, so they are skilled. Now I know that on the Big Dig in Boston, there was talk of using a lower grade or watered down concrete for the tunnel tubes (now they leak) and questions about the method used to fasten the concrete ceiling tiles and the final inspection of them prior to opening it (one fell on a car killing a young lady).
  • steverstever Guest Posts: 52,454
    A lot of the bridges built since WWII were designed for a 50 year lifespan. Plenty, right?

    Fugit inreparabile tempus.
  • fintailfintail Member Posts: 57,097
    And with real incomes stagnant at best, and materialism taking more control than ever, people will be very unwilling to pick up the tab for replacements or repairs.

    The future is going to be a mess.
  • tidestertidester Member Posts: 10,059
    If you are on a bridge when it collapses, are you more likely to survive in a car or an SUV? From the TV reports, I saw a lot of SUVs out there.
  • gagricegagrice Member Posts: 31,450
    Good question. I would say an old VW bug. They would float. You may end up in St Louis, cold, hungry and tired.

    I think the NHTSA will have to add a new safety test. Bridge collapse worthiness.
  • kurtamaxxxguykurtamaxxxguy Member Posts: 1,798
    Having lived in S. Calif. 25 years, I can vouch the heavy truck traffic has dramatically increased (possibly double) over those years.
    Many bridges have been reinforced for earthquakes, but this is for side-side sway and road joints from separating or sliding off the pylons.
    Some bridges are being rebuilt as they are widened, but there are some (several on the 710 freeway, a __major__ carrier of truck traffic) that are deficient.

    Then again, a recent visit to Portland, Oregon revealed an astonishing number of badly maintained bridges on the I-5 and elsewhere.
  • tidestertidester Member Posts: 10,059
    Bridge collapse worthiness.

    Or, perhaps, SCUBA gear in every vehicle?

    I've been wondering about all these people we have been watching giving interviews on TV. They tell us they were in free fall during the collapse - like 40 to 60 feet free fall - and yet they are able to talk about it? How much of a role did their vehicle type play in their survival?
  • tidestertidester Member Posts: 10,059
    (possibly double)

    At least. The population of California has just about doubled in 40 years.
  • john500john500 Member Posts: 409
    I've seen some references to the Philadelphia area in this thread. In the NY-NJ-Pa area, all bridges over the Delaware River and Hudson River are controlled by either the Delaware River Port Authority or the Hudson River Port Authority. When one calculates the amount of money that has been collected via tolls, it can easily be seen that the collected toll value represents the cost of several total bridge constructions over 20 years. It would be completely inexcusable for any of these bridges to fail. If any of these bridges ever should fail, the first action should be to hold all members of the Port Authority criminally liable for negligence. I'm not familiar with the organized crime (i.e. quasi-government) practices in Minnesota.
  • gagricegagrice Member Posts: 31,450
    I can tell you as a landowner in MN, it is highly over taxed. There is no excuse. They have given a lot of their tax dollars to promoting ethanol and other corporate welfare. That may be an underlying loss of budget dollars to maintain the infrastructure.

    The bottom line with maintenance of the infrastructure is the fact that it is not glamorous. Politicians want to say they are going to spend money to promote important projects like football stadiums.

    Bridges, not to worry!
  • fezofezo Member Posts: 10,384
    Right you are! Nice tie-in with the ethanol (hey if you could somehow blame Toyota here you;d have all your bases covered :P ).

    Putting aside my wise crack you know the calculation was that you can buy more votes with overpriced corn than with bridge maintenance.

    Meanwhile, with the authorities over here, most of the bridges are very nicely maintained but the Ben Franklin looks bad and there really isn't an excuse for it. The Tacony-Palmyra and Burlington-Bristol have no excuse. These things are gold mines.

    The PANYNJ seems to do pretty well with their crossings. The GW bridge looks as impressive as ever and holds as much traffic as you can throw at it. The Lincoln Tunnel is pretty amazing. I mean one tube goes back to the thirties and the third tube opened in 1957. I'd be hard pressed to tell you which tube is which. The only thing wrong with the Holland tunnel is that one end is in Jersey City. I don't suppose they can do much about that.
    2015 Mazda 6 Grand Touring, 2014 Mazda 3 Sport Hatchback, 1999 Mazda Miata 2004 Toyota Camry LE, 1999.
  • euphoniumeuphonium Member Posts: 3,425
    the sucking ferry system enabling a few to sail very cheaply to live on islands of grandeur & exclusivity.

    If those residents were to pay their freight on ferrys, not touching the fuel tax, the questionable bridges could be made safer sooner. Earthquake is the fearsome hazard. Sports fans enjoy Safeco and Qwest fields for their kid's games and they were financed with tax $'s.

    I could never understand why good people in the Inland Empire should pay fuel taxes to subsidize the Puget Sound ferries. :sick:
  • bigfurbigfur Member Posts: 649
    I went over the I35W bridge. It was making some noises but i didnt think twice because of the construction going on on the bridge. Problem MN has is that they take too much money and spend it in other places, i understand this isnt a political forum so ill just leave it at that. Had the state saved some of the money it was giving away i bet the bridge would have been fixed instead of "inspected more often". Keep in mind that heavy trucks such as semis and dump trucks cross almost EVERY bridge in America. To blame a bridge collapse on heavy trucks or suv or whatever is just wrong. These bridges are designed to handle much more weight then trucks could put on it. At this point i would have to put blame squarely on the state of Minnesota for not fixing the bridge when it knew it needed to be. (sorry for being long winded and harsh, but lets face it, that could be me they are searching for right now.)
  • tidestertidester Member Posts: 10,059
    These bridges are designed to handle much more weight then trucks could put on it.

    They are indeed designed to handle large static loads but I am not so sure that the cumulative effects of microstresses were adequately considered back in the 60s.
  • cooterbfdcooterbfd Member Posts: 2,770
    The only thing wrong with the Holland tunnel is that one end is in Jersey City. I don't suppose they can do much about that

    Sure they could, make it a one way OUT of NJ.

    What's the best part of being from NJ? Being FROM NJ!!! :P :P :P
  • fezofezo Member Posts: 10,384
    Yeah, but I'm still here......

    Down the shore though. Can't complain.....too much....

    We do have a wicked bridge that goes from our town to the barrier island next door. It's coming up on 50 years old. Is scheduled more major refurbishing but at least two years away. We'll see if the new inspections change that.
    2015 Mazda 6 Grand Touring, 2014 Mazda 3 Sport Hatchback, 1999 Mazda Miata 2004 Toyota Camry LE, 1999.
  • gagricegagrice Member Posts: 31,450
    Only cross that bridge during light traffic.

    What is funny is my wife has always hated going over big bridges. Maybe she knows something we don't. The odds are that we will not have another incident like this for many years.
  • grbeckgrbeck Member Posts: 2,358
    But what was the average weight of vehicles actually sold? And weights of passenger cars were increasing through the mid-1970s, before the great downsizing effort by GM began for the 1977 model year.

    For the 1960 model year, weights for the full-size Chevrolet ranged from 3,485 pounds (Biscayne two-door sedan with the six) to 3,960 pounds (Nomad wagon with V-8).

    By 1969, weights for the full-size Chevrolet were up to 3,530 for the comparable Biscayne, and 4,300 for the Kingswood Estate. By 1976, every full-size Chevrolet was well over 4,000 pounds, with some at 5,000 pounds. Almost every Chevelle/Malibu weighed at least 4,000 pounds, and this was supposed to be the midsized car.

    The comparable Fords showed the same growth pattern.

    Most of our infrastruture was built for 1960s full-size cars, and the weight of those cars was steadily increasing when those bridges and roads were built. I would think that this would have been taken into account when those roads and bridges were designed.
  • andre1969andre1969 Member Posts: 25,655
    is that these bridges are simply getting old. And when they need repairs and maintenance, there just isn't that much money in the appropriate budgets to do it right, so they go for the lowest bidding contractors, and try to cut corners whereever they can to make those dollars stretch further.

    A couple years back, I had to have a bunch of dumptruck loads of gravel for a driveway and garage I was putting in. Each load of gravel was 14 cubic yards, and one cubic yard was 3,000 pounds. So that's 21 tons right there just for the load! I'd guess that Mack dumptruck weighed about 8 or 9 tons itself, so figure the fully loaed truck would come in around 30 tons. And that's on a fairly compact footprint, i contrast to something like a bus or a tractor trailer.

    So after having to deal with a 30 ton mass, I don't think a private vehicle is going to make much difference, whether it's a Metro or an Excursion.

    Now if the road surface or some part of the bridge is starting to fail, a larger car/truck/SUV might do more damage than a lighter one, but I imagine that it's still just old age/lack of maintenance that's doing most of the harm, along with original construction that may have just been done quick and dirty.
  • andre1969andre1969 Member Posts: 25,655
    For the 1960 model year, weights for the full-size Chevrolet ranged from 3,485 pounds (Biscayne two-door sedan with the six) to 3,960 pounds (Nomad wagon with V-8).

    By 1969, weights for the full-size Chevrolet were up to 3,530 for the comparable Biscayne,


    I'm kinda surprised that a base '69 Biscayne isn't even heavier than that, when you consider how much they bulked up from 1960 to 1969. But then, wasn't the '60 still using the old "Blue Flame" inline-6? If so, that was a heavy engine, and just switching from it to the more modern 230/250 CID inline-6 probably saved at least 200 pounds.
  • lemkolemko Member Posts: 15,261
    Heaviest car I ever owned was a 1975 Cadillac Sedan DeVille which I believe weighed 5,128 lbs. Cars started to become lighter after that. Heaviest production car was the Russian ZIL which weighed somewhere in the neighborhood of 7,000 lbs!
  • lemkolemko Member Posts: 15,261
    The Collectible Automobile article on the 1957 Chrysler cars states they used more aluminum on their cars than the other makes. Other makes used about 40 lbs. of aluminum on their cars where Chrysler used about 100 lbs. Were the '57 cars lighter than the '56 cars as a result? You'd think with more widespread use of aluminum and plastic, today's vehicles would be a lot lighter. But then again, cars of the past didn't have stuff like NAV, better stereo systems than home units, and umteen airbags and electronic black boxes.
  • andre1969andre1969 Member Posts: 25,655
    Were the '57 cars lighter than the '56 cars as a result? You'd think with more widespread use of aluminum and plastic, today's vehicles would be a lot lighter.

    I'm pretty sure the '57 models were very close in weight to the '56 models, but not sure if they were lighter. I think the base weight of my '57 Firedome hardtop coupe is something like 3910 pounds, but I'd imagine the '56 was very close. I wonder if the 3-speed torqueflite transmission was much heavier than the 2-speed Powerflite?

    I think modern cars also have much more substantial bracing up underneath, where it matters. So while all that flimsy plastic and beer-can thick sheetmetal may scatter to the four winds in an accident, the remaining hulk will still protect the occupants better than an older car with thick sheetmetal, but inadequate sub-structure.
  • grbeckgrbeck Member Posts: 2,358
    I'm sure that the greater sound-deadening material, along with more sheetmetal, were offset with lighter engines.

    But bridge designers would have expected vehicles to get heavier, as that was the trend at the time (1960s).

    Of course, some bridge designers didn't need to worry about that. The bridge linking the Macungie Car Corral area to the rest of Macungie Park only has to be strong enough to withstand a certain 1974 Cadillac Calais hardtop that returns once a year... ;)
  • fezofezo Member Posts: 10,384
    57 Chryslers? Wouldn't it figure that only Chrysler could make aluminum rust?

    Andre hit on a couple of things that are exactly the problem. One is low maintenance You can't just let most of these things go without maintaining them. They will fail guaranteed.

    The other point is low bid contracts. Someone got the bright idea that the lowest bid is the best deal. Do you take your car to the cheapest mechanic? Have the cheapest contractor build your house? Use the cheapest plumber? I have dealt in these things and we invariably get the worst service for the cheapest price. This is all well and good when we are talking cleaning contracts but I can't tell you how many mistake ridden buildings we have because of this.
    2015 Mazda 6 Grand Touring, 2014 Mazda 3 Sport Hatchback, 1999 Mazda Miata 2004 Toyota Camry LE, 1999.
  • robertsmxrobertsmx Member Posts: 5,525
    Not just weight, but consider impact from increased traffic too. At the time the bridge went down, it was handling 141,000 vehicles per day (I’m assuming, both ways). Number of vehicles can take a toll too.

    Besides, someone earlier hit the nail right, poorer structural integrity may have to be blamed for the collapse stemming from "Quick Build" techniques that is more prevalent now than ever (not sure how things were, back in the 60s though).
  • euphoniumeuphonium Member Posts: 3,425
    out in the boon dox are not capable of the crossing by Emergency vehicles such as Fire tankers and even ambulances.

    The 15 residents of the unreachable area are happy using an old railroad flatcar so the FD asked them to make their bridge safe for their engines. The residents balked.

    Their lack of cooperation was met with researching the County Records to see who paid the annual tax bill. That revealed the mortgagee. The mortagee, upon being informed of the situation, divulged the name and policy number of the insurance company. The different insurance companies were advised of the problem and they wrote to each of the 15 residents advising them to install a safe bridge or get other insurance. Other insurance is not economically available. The 15 are being stubborn. :sick:
  • trispectrispec Member Posts: 305
    The trucks hauling large loads are the problem. The cars are simply to small to start the road and bridge damage in the first place. Once the trucks have done their damage of course any weight becomes contributory.

    Trucking in the country has simply gone nuts. We American's with our comparative wealth have lost even the slightest sensitivity to how much stuff we consume. Hundreds of years from now when society looks back (if we survive that long) the stories of waste are going to be completely shocking to our grand kids.

    The trucking industry still gets large subsidies from government. Make the trucking industry pay for the bridge and highway maintenance. Car drivers are definitely not the problem folks.
  • 1stpik1stpik Member Posts: 495
    We all pay MORE than enough money in taxes to maintain our transportation systems. This includes truckers, who pay fortunes in gas taxes on their 9 mpg rigs, plus more fortunes in other taxes and fees on everything from registrations to inspections to tires.

    The truth is that local, state and federal officials simply steal the tax money from the "trust funds" established specifically for construction and maintenance of roads and bridges. They vote themselves an ever-growing share of our taxes to spend on pet projects. Then when something bad happens, they try to blame us for not paying them enough money.

    Don't fall for this self-perpetuating scam.
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