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Texas Opens Fastest US Highway With 85 MPH Limit

Hugh Pickens writes "Most highways in the U.S. top out at 75 mph, while some highways in rural West Texas and Utah have 80 mph speed limits. All that is about to change as Texas opens a stretch of highway with the highest speed limit in the country, giving eager drivers a chance to rip through a trip between two of the state's largest metropolitan areas at 85 mph for a 41-mile toll road between Austin and San Antonio. While some drivers will want to test their horsepower and radar detectors, others are asking if safety is taking a backseat. A 2009 report in the American Journal of Public Health found that more than 12,500 deaths were attributable to increases in speed limits on all kinds of roads and that rural highways showed a 9.1 percent increase in fatalities on roads where speed limits were raised. 'If you're looking at an 85 mph speed limit, we could possibly see drivers going 95 up to 100 miles per hour,' says Sandra Helin, president of the Southwestern Insurance Information Service. 'When you get to those speeds, your accidents are going to be a lot worse. You're going to have a lot more fatalities.'"

50 of 992 comments (clear)

  1. Yeah but... by Anonymous Coward · · Score: 5, Funny

    It's in texas.

    So. There's that.

    1. Re:Yeah but... by ackthpt · · Score: 5, Funny

      It's in texas.

      So. There's that.

      It's Darwinism in action, but don't expect them to put that in the school books.

      --

      A feeling of having made the same mistake before: Deja Foobar
    2. Re:Yeah but... by MickyTheIdiot · · Score: 4, Funny

      Speaking of Darwinism... how many of those vehicles are pickup trucks with people sitting the bed?

    3. Re:Yeah but... by ackthpt · · Score: 4, Funny

      Speaking of Darwinism... how many of those vehicles are pickup trucks with people sitting the bed?

      In some parts of Texas that's known as Air Conditioning

      --

      A feeling of having made the same mistake before: Deja Foobar
    4. Re:Yeah but... by NFN_NLN · · Score: 5, Funny

      Speaking of Darwinism... how many of those vehicles are pickup trucks with people sitting the bed?

      Was that suppose to read:

      ...with people sitting in the bed?

      -OR-

      ...with people shitting the bed?

      because it could really go either way.

    5. Re:Yeah but... by operagost · · Score: 4, Interesting

      Montana ran with NO SPEED LIMITS, and overall, fatal accidents INCREASED when limits were put in again. Let's stop pseudoscience and politics from spreading death on our roads.

      --

      Gamingmuseum.com: Give your 3D accelerator a rest.
    6. Re:Yeah but... by HungWeiLo · · Score: 4, Funny

      Darwinism only affects the population if the dead driver has not yet reproduced. Since the minimum age for obtaining a driver's license is generally greater than the median breeding age in rural Texas, the increased speed limit may not have any impact on Darwinism's effects on the population there.

      --
      There are a huge number of yeast infections in this county. Probably because we're downriver from the bread factory.
    7. Re:Yeah but... by ackthpt · · Score: 4, Informative

      People refuse to obey the speed limits because the speed limits are retarded. Take any major highway in North America and you'll find massive stretches of more or less completely straight road where there's no reason you couldn't drive all day at your car's top speed, except, the posted speed limit is a third (or less) of said top speed.

      This will never change because the government strongly prefers to keep everyone a criminal, they're much easier to control that way. If speed limits were strictly enforced (and not increased to sane values), there would be riots in the streets.

      The science behind the building of the Autobahn lead to frequent bends in American highways. Ever notice they go a few miles, then suddenly veer a few degrees, then a stretch and veer back? It's to keep you alert because driving, at any speed, is metally fatiguing, moreso at night.

      Not unusual to see in the news someone fell asleep while driving and rolled a few times. The faster you are going when you roll the less likely you are going to be in a happy alive state when coming to rest.

      Speed limits also are well thought out as the average driver does not possess the skills of Mario Andretti, they're more along the lines of Ma and Pa Kettle. If your reaction time is poor at 65 MPH, going faster isn't going to help anything.

      --

      A feeling of having made the same mistake before: Deja Foobar
  2. Nothing new by orthancstone · · Score: 5, Informative

    "We could possibly see drivers going 95 up to 100 miles per hour."

    Hate to break it to Sandra, but that's the usual speed in many parts of Texas.

    1. Re:Nothing new by Jeng · · Score: 5, Informative

      Hate to break it to Sandra, but that's the usual speed in many parts of Texas.

      As well as Wyoming, only state where I have been passed while going over 100mph.

      --
      Don't know something? Look it up. Still don't know? Then ask.
    2. Re:Nothing new by countach74 · · Score: 4, Insightful

      Not necessarily. The problem with speed limits is they do not take into consideration the vehicle that's being driven, the vehicle's tires, or other various factors that contribute to the safety of those speeds.

      I agree that it increases the potential for Darwinism, but just because one drives at 90-100 MPH on the freeway does not necessarily mean that he or she is driving any more risky than someone driving at 60. Those of us who value our own (and our family's) well being don't drive based entirely on the speed limit. In certain conditions, I drive much slower than the speed limit because that's what's wise. It would be nice if I were also allowed to drive faster when safe.. you know, to make up for the times that I had to drive slower.

      Ultimately, I feel the real problem is that people have been trained to rely on the government to tell them what's right and wrong, what's safe and what's dangerous. It's total bullshit.

    3. Re:Nothing new by BinarySolo · · Score: 5, Funny

      Seems to me that Wreckless Driving is a good thing.

    4. Re:Nothing new by Megane · · Score: 5, Informative

      And...
      1: it's a toll road, which reduces traffic from the start
      2: it's a toll road, so there are fewer entrances and exits
      3: it's RFID toll tag or pay-by-mail (using license plate recognition cameras) ONLY, and existing toll booths on the north half will be removed, further reducing obstacles
      4: not only is it a divided highway (or "dual carriageway" as they say on the other side of the pond), but
      5: it's being built with a concrete surface, not asphalt (all the toll roads around Austin have been concrete) so you won't have potholes
      6: it completely bypasses the Austin metro area and the overloaded San Antonio to Austin I-35 route, even avoiding small towns (part of the point, since this would have been the route for the now-defunct TTC project)

      Even on the overloaded San Antonio to Austin section of I-35, traffic often goes 75-85mph when traffic is light.

      --
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    5. Re:Nothing new by Austerity+Empowers · · Score: 5, Informative

      Well I drive on this road all the time, it's practically deserted because the locals, who refused to fund it with taxes (red state - taxes are just for crack mothers and layabouts, not for roads and shit), are in some sort of quasi-rebellion against the overseas interest who owns the road and put the toll system in place. 85 feels very slow, just the comparatively short run between the Austin airport and round rock feels like you're in the middle of nowhere and may not even see a car much less pass one. Only complete pussies ever drove below 80 on this road, even when the speed limit was 65. Now I expect to see 90-95, but with the exception below, it's straight, wide and open. There isn't a much safer place to go fast that close to a major city.

      Unfortunately as all the toll road speed limits have gone up, more and more people are out seemingly in protest, driving side by side way lower than the speed limit. We don't have a right lane for passing only law here, so you're stuck with them. So it may be 85 mph, but in practice you're stuck with the slowest person on the road.

    6. Re:Nothing new by FSWKU · · Score: 4, Insightful

      There are also well published statistics about how fatalities increase as a result of going at a higher speed (which should be pretty obvious if you give it more than a few minutes of thought).

      Fatalities increase with speed, yes. Because higher speed means a crash has more destructive force than a lower speed. However, that does NOT mean that a higher speed CAUSES more crashes. It just means the crashes that may or may not have occurred either way are far more likely to kill you. And even at 65mph, if you wipe out, you're going to have a really bad day more often than not.

      --
      "So after all this, you make my case for me. To end this stalemate, you must die..."
    7. Re:Nothing new by Brooklynoid · · Score: 5, Informative

      You said: If there were no speedlimit people would, for the most part, drive INCREDIBLY riskily.

      Research indicates that this is not the case. In areas where speed limits are not enforced, civil engineers find that 85% of motorists drive at what most would call a prudent speed. In fact, in many municipalities, speed limits for a given road are determined by observing traffic and determining the limit based on the 85 percentile speed (assuming, of course, that generating revenue from speeding fines is not part of the equation). Google "85 percentile traffic speed" if you're interested.

  3. Rest of the world already ahead by Anonymous Coward · · Score: 4, Insightful

    Well, that's 136km/h - that's what our recommended travelling speed (130) on the "Autobahn" is in Germany.
    It has proven to be an excellent balance between emission (gears and cars are tuned to that speed), moving forward, but not braking too much due to other people's influences.

    Once again I have deep mis-respect for you "best country in the world" guys.

    1. Re:Rest of the world already ahead by repvik · · Score: 5, Informative

      And autobahn is one of the safest highways as well:

      Traffic zooms by on the German autobahn at 120 mph. The speed-limitless highway system stretches 6,800 miles and the Federal Ministry of Transport has declared the autobahn to be one of the safest road systems in the world despite the roaring, high speeds. US highways, on the other hand, rank as one of the most dangerous where speed limits range from 55 to 75 mph. Strict laws are believed to be the prominent reason the autobahn is safer than US highways.

      http://www.ehow.com/about_6726960_autobahn-safety-vs_-interstate-safety.html

    2. Re:Rest of the world already ahead by CanHasDIY · · Score: 5, Insightful

      Well, that's 136km/h - that's what our recommended travelling speed (130) on the "Autobahn" is in Germany. It has proven to be an excellent balance between emission (gears and cars are tuned to that speed), moving forward, but not braking too much due to other people's influences.

      Once again I have deep mis-respect for you "best country in the world" guys.

      From Expatica:

      The worst case Führeschein scenario is having to take a full driving course, like young German drivers do. "To get a regular driver's license," Christine explains, "you have to take 14 theory classes and at least 12 driving lessons. Driving schools usually offer them twice a week, so that takes about seven weeks. Depending on how quickly you learn, it can be done in about three months; but it usually takes longer, because of holidays and so forth. You start with the classroom sessions, and then move on to the driving portion, taking them in parallel so you learn the rules and also how to apply them." How many driving lessons you'll need to take depends on how quickly you learn. With 12 as the minimum, and 50 on the high end, the full licensing course can cost between EUR 1000-2000.

      Compare that to getting a license in the US:
      - @ 15.5 yrs, take lame written exam
      - @ 16 yrs, take lame driving "test" where you drive a couple laps around the city square or a big empty parking lot, then parallel park

      That is pretty much all the training most US drivers get, which may explain why we have significantly higher accident rates than Germany, even with lower speed limits on highways.

      --
      An enigma, wrapped in a riddle, shrouded in bacon and cheese
    3. Re:Rest of the world already ahead by chemicaldave · · Score: 4, Insightful

      German requirements to obtain a license are orders of magnitude more strict than in the States. Safe drivers make safe roads.

    4. Re:Rest of the world already ahead by cpotoso · · Score: 4, Insightful

      I've driven in the autobahn in Germany and in Austria. Some of them aren't that different than the typical US interestate, in fact I would even say that most interstates are actually better with wider lanes, more gentle curves and longer acceleration in-ramps compared to the autobahns I've driven in. Cars were not significantly newer/better either. The ONLY significant difference is that people actually use their BRAINS while driving in the autobahn. Specifically: you drive in the lane that corresponds to your speed, and pull to the right IMMEDIATELY after overpassing (because the BMW coming behind is coming pretty fast). Drivers going 200 km/h are extra careful, and assume that someone may pull in front of them to overpass another car. All in all, it is the fact that they are using the most important safety device, the BRAIN, rather than trusting some gizmo (technology, anti-lock brakes, etc) to keep them safe.

  4. It's an Effing Toll Road by CanHasDIY · · Score: 5, Insightful

    Don't like the higher speed limit? Don't drive on it.

    Doesn't get any simpler than that.

    --
    An enigma, wrapped in a riddle, shrouded in bacon and cheese
    1. Re:It's an Effing Toll Road by reidconti · · Score: 4, Insightful

      What, what an asshole move. Not only do you care so little about safety that you threaten to cause bodily harm to another driver because you *don't like the way they drive*, but you're perfectly fine with causing massive traffic jams. Have you ever noticed how most instances of really heavy (but rolling) traffic occur because there's some inconsiderate driver with no lane discipline, no ability to look in their mirrors, and a self-important outlook on their driving, who is holding up countless cars behind them by going slow in the left lane?

      Yeah, probably not. You wouldn't notice something like that.

  5. Here's a safety tip: by Opportunist · · Score: 4, Funny

    With a speed limit of 10mph, you can virtually eliminate car related deaths on highways!

    --
    We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
    1. Re:Here's a safety tip: by ColdWetDog · · Score: 4, Funny

      With a speed limit of 10mph, you can virtually eliminate car related deaths on highways!

      You're forgetting something. At 10 mph, driving through Texas would kill people either from boredom or old age.

      --
      Faster! Faster! Faster would be better!
  6. Autobahn by Anonymous Coward · · Score: 5, Insightful

    The sad fact is that its not speed that kills, its differential speed. Unfortunately our drivers training here is not really up to the standards it should be with modern machines. If you look at Germany they take drivers ed a lot more seriously, as well as licencing, with 6 month courses costing thousands of dollars being the norm. As well the rules of the Autobahn are strictly enforced, if you're going slow in the left lane you WILL be pulled over, just as quick if not quicker than you would for "speeding". Same with sudden lane changes, and just general bad driving. Speed doesnt kill, dumb drivers do.

    1. Re:Autobahn by MozeeToby · · Score: 4, Interesting

      If you can't safely keep up with traffic you need to switch to a road where you can. If your work truck can't reach the speed limit, take a different route. IMO, there should be an implied minimum speed of 5 under the posted limit with very few exceptions. I'd be willing to bet that you'd see fewer accidents if that were the case.

    2. Re:Autobahn by Attila+Dimedici · · Score: 4, Insightful

      If I'm doing the speed limit in the far left lane you have no right to bitch.

      If you are not passing another vehicle, than you are breaking the law and are doing something that is not safe. If you are not passing another vehicle, get out of the passing lane.

      --
      The truth is that all men having power ought to be mistrusted. James Madison
    3. Re:Autobahn by almitydave · · Score: 4, Informative

      Going a safe speed is the most important thing, I applaud you for that, but there are a couple of other relevant facts:
      1) Impeding the flow of traffic is illegal.
      2) Driving in the passing lane without passing is also illegal.
      3) Your speedometer may not match those of other drivers. They may be "going the speed limit" as well.

      I've heard this argument many times, and people need to remember there are more laws than the speed limit that govern how you should drive, especially what lane you should be in. Respecting the posted speed limit is good, but so is respecting all those signs that say "slow traffic keep right." If your aim is to follow the law, follow ALL of them. And probably don't assume people going faster are jerks. Speedometers can vary quite a bit. See Car and Driver's feature on the topic.

      --
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      I'm, you're, he's/she's/it's, we're, you're, they're
  7. Autobahn by mbone · · Score: 4, Interesting

    The German Autobahn's have no speed limits in rural areas. I have driven at 160 Kph (i.e., 100 mph) and been routinely passed by faster vehicles. In fact, if you are in the left lane at that speed, they may get pretty annoyed with you if you don't get over immediately.

    My understanding is that the German Auto Club serves a function much like the US NRA. Touch the speed limit, and your political career will be limited.

  8. stupidest argument ever by v1 · · Score: 5, Insightful

    'When you get to those speeds, your accidents are going to be a lot worse. You're going to have a lot more fatalities.'"

    That happens anytime you raise the speed limit. from 55 to 65. from 45 to 55. from 10 to 20. We've already had this argument brought up multiple times, and you lost. Take that argument and go away.

    Statistically speaking anyway, once you're hurtling down the road at 65 mph or faster, you're already well over the curve for speed-to-lethality tradeoff. Dropping your odds of survival from 2% to 1.8% really doesn't impress me that much.

    --
    I work for the Department of Redundancy Department.
    1. Re:stupidest argument ever by TheCarp · · Score: 4, Insightful

      Add that to research that suggests that many people drive at the speed they feel comfortable at, regardless of the posted limit, and it really is a very good question.

      What is the point? Personally, I think its because some people like the idea of being able to pull over any car at will. Just keep the rules in that area where most people break a few as a matter of course, but not so egregious that its obvious thats what you are doing, and its both a money source and a source of arbitrary abuse of power.

      I have heard it directly from cops mouths.... if they want to pull someone over, the standard wisdom is, all they have to do is watch them for a few minutes and they will find a reason. What does that say about the standards that are set?

      --
      "I opened my eyes, and everything went dark again"
  9. Stay out of the left lane if you're not passing by Control-Z · · Score: 5, Insightful

    Just stay out of the left lane when not passing and driving will be much safer for everyone.

  10. Re:Net actual speed by Desler · · Score: 4, Informative

    You don't have to pull over. It has cameras that check your toll tag on your car or snaps your license plate to charge you for the trip. Any modern tollroad is like this. They do have places to pull over if you want to pay in cash but it's not required. You can blas up 45 miles from Austin to Georgetown currently without ever stopping.

  11. Please raise it 88 MPH. I have a Delorean. by Cutting_Crew · · Score: 4, Funny

    Then you really dont have to worry about anything. of course when traveling back and forth in time i could always collide with another vehicle. Oh and i also need lightning.

  12. Re:Apples and Oranges by WillAdams · · Score: 5, Insightful

    When I was stationed in (middle-of-nowhere) Texas in 1987--8, the drivers were courteous to a fault, and pulling over onto the (fully paved) shoulder to allow a faster car overtaking one was the norm.

    --
    Sphinx of black quartz, judge my vow.
  13. I drive that road regularly by snadrus · · Score: 4, Informative

    I've been to the North-East US and understand that most roads in Europe look the same, so here's what's to know about this road:
    - This road is where there is a lot of flat land. Even at 85 you can see where you will be in a few minutes (and virtually not take a turn until you get there). You can also see any animals that may enter this road, but it's mostly a bridge anyway which avoids that.
    - There's nothing to see on this road. No billboards or distractions. No gas stations, restaurants, few farm houses. Few exits.
    - The road has heavy steel guard rails that would stop most anything driving along it. These rails are after over a car lane of margin. A few places don't where it's just flatland for 1000s of feet.
    - The state-standard noisy edge-of-the-road keeps drivers from hitting the road's guard rails.
    - If I drove you on it blindfolded (in a car whose engine noise doesn't give away the speed like mine does), you'd think we were driving - Very light traffic. No old cars
    - The biggest risk was just getting bored, & speed helps this.

    --
    Science & open-source build trust from peer review. Learn systems you can trust.
  14. There's nothing Darwin about it. by raehl · · Score: 5, Insightful

    There is nothing unsafe about driving very fast on roads designed for driving very fast. You are FAR safer driving on a restricted-access divided highway at 100 MPH than you are driving on a 45 MPH city street with cross traffic, or a country road. Especially now that many states are putting up those cables in the median that prevent cars from getting across into oncoming traffic.

    Even the article summary has to grasp for straws in trying to provide a "balanced" summary.... this 85 MPH divided highway is apparently unsafe because.... driving fast on country roads increases fatalities!

    But a divided highway is not a country road.

    Accidents between two cars going in the same direction at relatively the same speed (+/- 10-15 mph) are rare. It's the car going 35 MPH+ one way that encounters another car going 35 MPH+ in a different direction (hed-on or cross traffic) that kills people. Divided highway fatalities are usually coming up on stopped traffic in fog or at night, or falling asleep and leaving the highway.

    One more point to note ... if you're going to get in a single-car accident at 65 MPH and hit a pylon or something, you're dead. If you do it at 85 or 90 MPH, you're just REALLY dead. Same difference.

    1. Re:There's nothing Darwin about it. by tibit · · Score: 4, Insightful

      65mph frontal crashes into a wall/pylon larger than the car's front are survivable in plenty of modern cars. Just barely, perhaps, but they are. Arguably, for such a "survivability", I'd much rather go 85MPH and not make it for sure.

      --
      A successful API design takes a mixture of software design and pedagogy.
    2. Re:There's nothing Darwin about it. by jythie · · Score: 4, Insightful

      Thing is, you can only engineer so much into the highway's design before you start encountering more problems on the human side. Reaction times do not improve, and unfortunately people rarely increase their following distance when driving faster (esp as the number of users increases), so yes, higher permitted speeds tend to result in more accidents.

      Thing is, this isn't a politician, scientists, or institution saying this, it is the insurance companies. They tend to do a pretty good job of cutting through the BS since their profits are directly connected to actually things right.

      And while it is true that such collisions are 'rare', they are still common enough to be a daily occurrence on most major highways

    3. Re:There's nothing Darwin about it. by xaxa · · Score: 4, Informative

      The biggest difference is the time travelled during the reaction time.

      In 1.5s (standard reaction time), a car travelling at 85miles/hour travels 10 metres further than one travelling at 70miles/hour.

      Once the brakes are applied, perhaps to avoid an obstacle, the car travelling at 85miles/hour will be travelling significantly faster than the 70miles/hour one when it hits the obstacle -- braking isn't linear, and the difference between hitting the obstacle at 5mph and, say, 40mph can be fatal)

    4. Re:There's nothing Darwin about it. by Carewolf · · Score: 5, Informative

      The other point is people regularly drive over the speed limit, regardless of the speed. SO when you are doibng 85, some a hole is doing 120. Drive at 120 is different the 65 and 85. Wind and air pressure at 120 can cause you to lose control.

      A car going past you at 120mph is not going to give you nearly as much turbulence as overtaking a truck doing 60mph. In fact one of the reasons a fast car can go 120mph is because it doesn't cause a lot of turbulence. It can be a bit of a shock to be overtaken by someone going 150mph, when you are already going 100mph in Germany, but beyond the surprise it is not affecting you.

    5. Re:There's nothing Darwin about it. by Anonymous Coward · · Score: 5, Insightful

      People like to point to the Autobahn for speeds like this but there are clear differences.

      - Licenses are much harder to get in Germany and require much stricter testing
      - The high speed roads are very well maintained and are not straight so they tend not to create driving "hypnosis"
      - People take driving more seriously on the Autobahn instead of treating it like a game or a chance to play with their phones

      Hit a bump in a road at 90+ and your average SUV would probably lift off the ground and lose control.

    6. Re:There's nothing Darwin about it. by schlachter · · Score: 4, Insightful

      most of us are driving 70-80mph anyways when the limits are 55-65mph...and arbitrarily enforced. Why not just make the limits 85mph and enforce it strictly? Far less ambiguity and stress for the driver. And no need to negotiate down tickets or argue when pulled over.

      --
      My God can beat up your God. Just kidding...don't take offense. I know there's no God.
    7. Re:There's nothing Darwin about it. by sarysa · · Score: 4, Interesting

      most of us are driving 70-80mph anyways when the limits are 55-65mph...and arbitrarily enforced. Why not just make the limits 85mph...

      The safety freaks will say people will start going 95-105mph if you raise the speed limit to 85, and people listen to them.

      I can guarantee you that unless it's a steep downhill, there's no way I would've done so with the $500 cars I used to drive or the much nicer vehicle that I drive now. (which is an SUV -- I'm not often motivated to go 90) The only time I ever hit 100 was going downhill on Nevada's highway 6 (I think that's it, it's near 50 which is the "lonliest road in America"), which has no other traffic whatsoever and is generally a long straightaway. Yeah, you have your performance freaks who are already frequently going 90 and weaving in and out of traffic who might gain the confidence to make 100 their average, but that fringe does not represent the majority.

      I sure hope safety is taking a back seat. We've gone WAY too far in terms of safety to the point where it's become some kind of mortality derangement. Life is a fatal disease, and there's no way to prevent driver fatalities unless we all go 10mph and prevent the physically infirm from driving. Frankly I find the chaos of Mexico's highways more appealing than the excessively proactive, taxation-masquerading-as-safety scheme we have on American highways today.

      --
      Charisma is the measure of someone's ability to lie with a straight face.
    8. Re:There's nothing Darwin about it. by nbauman · · Score: 4, Informative

      I've read about a hundred papers on auto collisions and talked to a couple of dozen auto safety engineers to make sure I understood what I was reading. The fatality rates of automobile collisions increase by about a square function of the speed. When you have a collision, you have a lot of energy to dissipate, and KE = 1/2 mv^2.

      I don't have my files around to cite, and I've forgotten most of my college physics, but here's the bottom line (Fermi exercise; the numbers may not be right, but if you have better numbers you can recalculate it for me):

      1. According to a presentation on front-end collisions I read in Automotive News by a Mercedes-Benz engineer, it's impossible to make a car that will keep you alive in a front-end collision into a rigid barrier at more than about 50 or 55mph.

      A car crashes into a barrier. The occupants are restrained by their seat belts. The front end of the car crushes until the car comes to a stop. The front end, from bumper to firewall, is about 50 inches. The maximum deceleration the occupant can survive is 50g. When you run the numbers, the initial speed is about 50mph. With those parameters, the front end of the car is completely crushed, up to the firewall, and the passenger compartment is intact. Above that speed, the engine goes into the passenger compartment, the passenger compartment crushes and collapses, and the collision usually isn't survivable.

      The engineer said that you can't raise the survivable speed significantly, because the front end would have to be impractically long (that 50 inches would increase as the square of the speed).

      There might be somebody out there who drove into a brick wall at 65mph and lived. This is an idealized model, and specific circumstances can affect it.

      But that's the physics of most head-on collisions, and it's been confirmed in collision labs and in accident investigations on the road.

      In fact, most people don't survive a head-on collision at >55mph, as this classic study http://papers.sae.org/670925/ by Nils Bohlin http://en.wikipedia.org/wiki/Nils_Bohlin found out. Great read, BTW (if you're a physics/engineering nerd).

      2. OK, so not all collisions are head-on into a barrier. Let's assume that Texas road is designed well enough to avoid that. Let's assume it's lined on the sides with breakaway signs, popcorn-filled barriers and right-of-ways filled with sand.

      You've got people driving along at 85mph. For a certain number of those cars, something will go wrong. Maybe a tire will blow. Maybe one car will bump another. Maybe a wheel won't be aligned right. (I've seen wheels fall off.) There will be a lot of human failures, like drivers falling asleep, or failing to pay attention,

      Once you have the initial disruption, a car at 85mph (vs. 55mph) (a) is much less stable, and much harder to get back under control and (b) has a lot more energy to dissipate before it comes to a stop.

      Maybe you'll be lucky and slide to a stop along the pavement, but the physics is against it. If you don't crash against a barrier, that energy tends to convert to rolling energy.

      The tendency is to roll, along a couple of axes. First you roll across the horizontal plane, until the car is perpendicular to the direction of travel. Then the car flips over, and usually rolls until it stops. Rollover accidents are the most fatal. Racing cars are built with reinforced tops and rollover bars that can take a rollover, but when I was studying this stuff, the roofs of passenger cars usually collapsed after one or two rollovers, and even if they didn't collapse, the occupants got a lot of damage.

      So you're going to roll over a lot more violently, and a lot farther, at 85mph than you would at 60mph.

      Whether a driver should risk his life and brain by driving >85mph is a question that physics can't answer. But the death rate goes up pretty fast above 55mph.

      As my physics professor used to say, I don't care if you kill yourself, as long as you get the physics right.

  15. Re:Apples and Oranges by LoudMusic · · Score: 4, Interesting

    I'm not saying you're wrong, but look at it from the other car's perspective. They're gaining on the truck at 40 KPH, which is fairly quick, and they check their mirror and see nothing so they go for the pass. Before they get around the truck you've shown up gaining on them at 130 KPH. Before they can accelerate out of the way you have to slow down to avoid rear-ending them.

    No one is at fault for this - it's just the nature of a road system that allows such diverse speeds. In the US on roads which allow high speeds, typically greater than 60mph, there is also a minimum speed not more than 30mph below the maximum. If you don't have a maximum speed designated for the road it's much harder to manage a minimum speed.

    One thought I've had is to have speed ranges defined per lane. It works best on roads with 3 or more lanes. Lane 1 would be 50-100 KPH, lane 2 would be 80 - 150 KPH, lane 3 would be 130 - 200 KPH, lane 4 would be 180 - unlimited KPH.

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  16. The predicted carnage numbers don't add up. by djl4570 · · Score: 4, Interesting

    Years ago when we finally got rid of the double nickle speed limit there were people predicting carnage on the nations highways. I tried to run the numbers and came up with inconsistent results. Here's a couple of stats I remember from that era:
    AAA reported that over eighty percent of injury accidents occur at speeds under forty miles per hour and within a few miles of home. This was in their monthly magazine.
    At the same time it was widely reported that half of all traffic fatalities were the result of intoxicated drivers. (Alcohol, drugs.)
    Those two stats leave very little room for accidents on high speed freeways where speed is the sole factor in the accident.

  17. Wrong, does not always happen by SuperKendall · · Score: 4, Interesting

    That happens anytime you raise the speed limit. from 55 to 65.

    Accident rates in Colorado lowered when they raised the speed limit from 65 to 75.

    One good reason you are not accounting for is that no matter what the speed limit is, drivers drive at a speed they consider comfortable on a highway. That means that people like you imperil everyone else by sticking close to an old and arbitrary speed limit. Once you raise the limits there is a much greater equalization of people driving around the same speed, making the whole road safer.

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    "There is more worth loving than we have strength to love." - Brian Jay Stanley
  18. Re:Apples and Oranges by Anubis+IV · · Score: 4, Informative

    Still done that way today. I occasionally take SH 79 back and forth between Austin and Hearne, which is a 65mph road with one lane in each direction for the vast majority of it. Even when the difference in speed is minimal, a large percentage of drivers will use the shoulder as a "get out of the way" lane to allow someone to pass if they're unable to get around on their own due to oncoming traffic. There have only been a small handful of times that I haven't seen that happen, and even then, those drivers were still going at least the speed limit.

    Texas drivers still don't honk at each other either. I've seen people sit through two full cycles of a stop light without honking at the car at the front of the line that for some reason didn't go either time. Having grown up in south Florida, which has a very northeastern U.S. culture due to all the snowbirds down there (i.e. honking is a way of expressing the fact that the light is almost green and you haven't started rolling forward yet) , it continues to boggle my mind.