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I just read all 64 pages in two days. Man, I have a completely new appreciation for Traffic Engineers now. The things you guys do, awesome! Do you ever use variable speeds on roads? I saw the 85th percentile stuff a few pages back, but for roads like this (Reeweg / Waalhaven WZ/ZZ/OZ), the problem is that between 7AM - 10AM and 4PM - 6PM there's a lot of traffic there (and thus 50km/h is a reasonable speed), while at any other time you could easily go 80km/h there. And another question, would you prefer a roundabout there? People are pretty split on that over here, mostly because the majority of traffic are trucks and the railways making things complicated. It'd definitely speed things up, though. Oh, and follow that highway east for some great intersections. I love our Ring 
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Sep 30, 2010 13:10
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I would guess that if they put in a roundabout, it would be best to have bypasses from Waalhavenweg heading south to Reeweg and from Reeweg to east on Waalhaven Z.z. Big truck apron around the middle and wide lanes could probably do it. That's assuming there's roughly equal volume coming from each way, otherwise the intersection would probably be better.
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Sep 30, 2010 14:36
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Doesn't heavier traffic by nature regulate it's own speed? The more congested it gets the slower people are forced to go anyway.
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Sep 30, 2010 15:02
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Choadmaster posted:Doesn't heavier traffic by nature regulate it's own speed? The more congested it gets the slower people are forced to go anyway. The automatic speed limit signs should be increasing with congestion, not decreasing 
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Sep 30, 2010 15:24
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jeoh-kun posted:I just read all 64 pages in two days. Man, I have a completely new appreciation for Traffic Engineers now. The things you guys do, awesome! We do have variable speed limits in some places. They're more reactive than proactive, though. I don't know how many people actually obey them because it's the law, or obey them because conditions are bad and they would have done slowed down anyway. jeoh-kun posted:And another question, would you prefer a roundabout there? People are pretty split on that over here, mostly because the majority of traffic are trucks and the railways making things complicated. It'd definitely speed things up, though. Normally, with that lane arrangement, I'd say no. However, since it is Holland and people are used to bigger roundabouts, and there seems to be plenty of right-of-way. I'll go with my usual "I'd need to see the volumes" disclaimer, but it seems like it could be done. A little clever engineering, and it will probably work well. Even if the capacity's not great, the accidents will at least decrease.
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Sep 30, 2010 17:21
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grover posted:If we have twice as many people on the road, they all have to drive twice as fast to maintain smooth traffic flow. Simply physics. Instead, they do the opposite!! Ah, but it's headways that ultimately determine capacity, not so much speed  When everyone can drive half a second behind the car in front, instead of two seconds, that's when capacity will be awesome.
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Oct 1, 2010 03:25
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Choadmaster posted:Doesn't heavier traffic by nature regulate it's own speed? The more congested it gets the slower people are forced to go anyway.
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Oct 1, 2010 16:20
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Socket Ryanist posted:I've been on too many freeways where everyone is 2 carlengths apart going 70 mph or more, so I'll say... no I've driven through LA too  . But the same people seem to drive right off each other's bumpers in light traffic too.
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Oct 1, 2010 20:28
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Choadmaster posted:I've driven through LA too They're balanced out by the folks who drive 40 mph in every condition. Aggressive drivers mean higher capacities, even if more accidents come along with it.
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Oct 1, 2010 21:42
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Robot driven cars means 100 mph and inches of following distance. Or vacuum tubes. Whatever works.
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Oct 2, 2010 16:23
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Guy Axlerod posted:Robot driven cars means 100 mph and inches of following distance. Or vacuum tubes. Whatever works. Technically, we could already have drive-by-wire cars where you lay down and drive looking at a screen overhead. We already fly-by-wire and sail-by-wire and even automatic trains, so how hard would it be? If you've ever had an electrical failure in your car, imagine that it would make the steering entirely unresponsive and the screen dark, or better yet, disengage a robotic driving service that has taken care of driving for you for five years up to now. Airplanes and ships are such big investments that the buyer will gladly give you some extra time to iron out all the bugs, but cars are relatively cheap and need to get off the drawing board and into the showroom in a much shorter cycle. Combine this with the sheer multitude of environments a single car may encounter during its lifetime and you come to the conclusion that investments poured into automatic driving systems have a much higher chance of bombing spectacularly than they would in airplanes, ships or trains. Volvo tried recently to make a car that would automatically brake if you were in danger of hitting something. The demonstration didn't go exactly as planned. Given the pace things are going, I'd still give robotic cars some 30 years.
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Oct 2, 2010 22:09
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What if you had a bunch of high-capacity automated cars on a pre-set track using proven existing infrastructure and can be semi-computer automated, yet still overseen by by real human drivers? You could even link them together for even more capacity.
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Oct 2, 2010 22:44
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So Vacuum Tubes then? You seem to be talking about it like I want it done tomorrow. I'm talking about the beep boop future where robot driven cars work and work well. Did you see WallE? Like on the spaceship, but with hopefully fewer fat people.
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Oct 2, 2010 23:51
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No, I'm talking about trains.
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Oct 2, 2010 23:59
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If you like crazy near-future prototypes, this site has some nice ones. How about a truck you drive onto a railway? Or a giant bus that splits apart so you can make it diesel or electric by plugging a different drive section at the front?
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Oct 3, 2010 00:01
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theflyingexecutive posted:What if you had a bunch of high-capacity automated cars on a pre-set track using proven existing infrastructure and can be semi-computer automated, yet still overseen by by real human drivers? You could even link them together for even more capacity. There was an article in either Discover or Scientific American a few years ago about this. There were tiny pod-cars, each holding one person, that would daisy-chain and take up about half a lane. In the case of a mechanical failure, having the pods linked together would provide some redundancy. Without that, though, every time a tire popped or debris fell into the road, there would be a huge pile-up. Probably still safer than human drivers, but I think people will prefer 10 self-inflicted accidents to one they can't control or anticipate.
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Oct 3, 2010 01:41
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The point I was really making is that nobody would trust [s]drive by wire[/i] automatic navigation cars, no insurance company would insure a company that made them, and no manufacturer would be able to make a completely foolproof system. The ridiculous mental hurdles you have to go through are solely because Americans are so infatuated with cars. Just take a look at car commercials: a single car on a curving road with no other traffic on a beautiful day, a situation that would almost never happen. The exaggerated feeling of freedom that cars give people means that our alternative medium-distance transportation infrastructure (rail, light rail, buses, hell, even carpooling) falls into disuse and people like Cichlidae have to figure out how to crunch every last modicum of efficiency from infrastructure that was planned out half a century ago to accommodate ever-increasing demand because of a stigma surrounding public transportation. Only when car ownership becomes so infeasible as to necessitate expanding higher-capacity transportation do people actually call for it, but by then there's no money, space, or resources to make it happen. edit: Sorry, I guess I mean automatic navigation theflyingexecutive fucked around with this message at 06:40 on Oct 3, 2010 |
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Oct 3, 2010 05:17
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One thing to keep in mind here is to use the proper terms for what we want. We already have throttle-by-wire, and technically the hydraulic systems that operate your power brakes work in the same way - just with fluid in a line instead of electrical signals on a wire. Better hope your brake lines are well maintained. Nobody blinks an eye about it either. If you spring a leak, you have no brakes except for your E-brake. Even then, a "brake by wire" system would be more complex than the current power brake systems. They'd cost a lot more for about zero benefit. I'm sure we could have steer-by-wire if we really wanted it, but this is one case where mechanical linkage and hydraulics makes the most sense because it's cheap, proven, and easy to implement and on a very small scale. There's no efficiencies of scale to be gained by going steer-by-wire, as opposed to throttle by wire. You'd have to basically reinvent the entire steering system for minimal gain. Keep in mind that "fly by wire" in an airplane does not imply automatic flight, that's the job of the autopilot/flight director, and you can have that in an airplane with all hydraulic controls or even manual linkages. In the simplest of terms, all fly-by-wire does is replace thousands of feet of expensive hydraulic lines with, relatively speaking, cheaper electrical wiring. The control surface actuators are now free to be either electrically operated or operated by much smaller, easier to service hydraulic systems actuated by computer. Now, the computer used in a fly by wire system does interpret all of your inputs and makes the airplane do them, and thus allows the airplane to not be pushed beyond its performance envelope, for instance. But it's a separate thing from true automation. Fly-by-wire/main hydraulic control are also implemented because the large control surfaces on airplanes that use them are pretty impossible to move on human power alone, and this is not the case for car scale systems. Power steering and brakes are a convenience to ease driving, yes, but they are far, far weaker than the systems used in aviation and are so far less complex. It's like comparing a Commodore 64 to an iMac. Automated driving (which is what you guys are describing) doesn't need drive by wire to work. In a perfect world it would make it easier to implement, yes, but it is by no means necessary. kefkafloyd fucked around with this message at 05:45 on Oct 3, 2010 |
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Oct 3, 2010 05:40
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kefkafloyd posted:One thing to keep in mind here is to use the proper terms for what we want. This diagram shows the e-brake as a foot-pedal, but it would be the same if it was a hand-lever. Same with the rear drums; the diagram would look identical if they were rear disks. 
grover fucked around with this message at 11:26 on Oct 3, 2010 |
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Oct 3, 2010 11:22
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theflyingexecutive posted:The point I was really making is that nobody would trust [s]drive by wire[/i] automatic navigation cars, no insurance company would insure a company that made them, and no manufacturer would be able to make a completely foolproof system. The ridiculous mental hurdles you have to go through are solely because Americans are so infatuated with cars. Just take a look at car commercials: a single car on a curving road with no other traffic on a beautiful day, a situation that would almost never happen. The exaggerated feeling of freedom that cars give people means that our alternative medium-distance transportation infrastructure (rail, light rail, buses, hell, even carpooling) falls into disuse and people like Cichlidae have to figure out how to crunch every last modicum of efficiency from infrastructure that was planned out half a century ago to accommodate ever-increasing demand because of a stigma surrounding public transportation. Only when car ownership becomes so infeasible as to necessitate expanding higher-capacity transportation do people actually call for it, but by then there's no money, space, or resources to make it happen. Car commercials are nothing but wide open country driving and driving through the empty streets of Manhattan. Except for minivans, nobody shows cars in the suburban hell holes they're likely to end up in. I wonder if advertisers have a better grip on the what Americans want than the rest of us Americans.
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Oct 3, 2010 16:04
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grover posted:A lot of cars (all?) have two separated sets of hydraulic lines and split chambers in the master cylinder so that even if one line leaks, braking is only lost on two wheels, and the car can still brake on the other two wheels. Including the mechanical e-brake/parking brake, there's at least double redundancy everywhere, and triple redundancy in the most vulnerable areas. You're right, I had forgotten about split master cylinder systems. This is true, but the type of redundancy used in cars is still far less on a scale than the often quadruple actual line redundancy to multiple control surfaces used on an airplane. It's still possible, but extremely unlikely, that both splits fail, but obviously even then the E-Brake is still there.
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Oct 3, 2010 16:36
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kefkafloyd posted:You're right, I had forgotten about split master cylinder systems. This is true, but the type of redundancy used in cars is still far less on a scale than the often quadruple actual line redundancy to multiple control surfaces used on an airplane. It's still possible, but extremely unlikely, that both splits fail, but obviously even then the E-Brake is still there. The results of a brake failure are a whole lot less catastrophic in a car than in an aircraft. You may wreck your car, but you're likely to walk away from it. If you lose control of the elevator on your jet, though?
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Oct 3, 2010 17:04
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kefkafloyd posted:You're right, I had forgotten about split master cylinder systems. This is true, but the type of redundancy used in cars is still far less on a scale than the often quadruple actual line redundancy to multiple control surfaces used on an airplane. It's still possible, but extremely unlikely, that both splits fail, but obviously even then the E-Brake is still there. Those redundant hydraulic lines on planes have a tendency to fail catastrophically at the same time, too.
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Oct 3, 2010 17:41
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grover posted:The results of a brake failure are a whole lot less catastrophic in a car than in an aircraft. You may wreck your car, but you're likely to walk away from it. If you lose control of the elevator on your jet, though? As long as you've got thrust, you can still fly the plane to some degree. But that's why planes have quadruple redundancy. I guess my point is that steer or brake-by-wire isn't going to happen not for safety or insurance reasons, but because on the whole it's impractical and too expensive on such a small scale. On an airplane, the scale is so large that fly-by-wire makes a lot of sense. Some might bring up throttle-by-wire, but it's a bit of a different scenario. Throttle by wire happened because it's actually stupid easy to implement, is pretty cheap, and has benefits that outweigh having a physical throttle cable, like eliminating mechanical complexity on cruise control. A throttle cable is a very small, simple system to implement compared to a steering system or brake system. Of course, it has its drawbacks - witness the Toyota accidents. edit: quote:Those redundant hydraulic lines on planes have a tendency to fail catastrophically at the same time, too. A well-designed multi-hydraulic system would be designed in such a way that if you lost hydraulic pressure to, say, your elevator, you wouldn't lose it to the ailerons, flaps, or vertical stabilizer. You also have hydraulic fuse blocks to prevent loss in one system from draining the entire system. The multiple redundant lines should also be routed to different areas of the aircraft. Obviously if you have a situation like the DHL Airbus A300 where you have something the designers didn't anticipate (being hit by a missile), you're kinda boned, but those guys landed that plane using only thrust. Japan Airlines 123 did have total hydraulic failure - but that's because it was missing half of its tailplane due to bulkhead failure. Even then they were still able to use thrust steering and elevation until they simply ran out of air to fly in by virtue of landing into a mountain. The 747 is a great example of designing multiple hydraulic systems, because in many situations where control was lost on one surface you still had other surfaces to work with. Complete total loss of all four hydraulic systems on that aircraft usually requires something that will kill you anyway, like losing most of the tailplane. This is opposed to the original design of the Douglas DC-10, which had tons of flaws in its redundant systems. Many systems were routed within single points of failure (such as all hydro lines being routed within the same area on the vertical stabilizer's engine, so an uncontained engine failure could destroy all the hydro lines). It didn't have hydraulic fuses in its original design so that if the hydro system for the horizontal stabilizer failed, you'd lose your flaps and ailerons too. Even then, the guys who had the task of flying United 232 to Sioux City still managed to do it under engine thrust alone and would have made the first successful hydro-free landing had they not had the bad luck of some wind pushing a wingtip down to strike the ground. Obviously if you lose both engines, you'll lose hydro pressure, but if this happens at most stages of flight, you'll still have the ram air turbine to work with for some hydraulic assist. Fly-by-wire aircraft have performed twin engine failure landings in the past as well (Air Transat 236). kefkafloyd fucked around with this message at 18:34 on Oct 3, 2010 |
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Oct 3, 2010 18:06
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kefkafloyd posted:I guess my point is that steer or brake-by-wire isn't going to happen not for safety or insurance reasons, but because on the whole it's impractical and too expensive on such a small scale. On an airplane, the scale is so large that fly-by-wire makes a lot of sense. How about we approach this from the other side? Driverless trains are commonplace these days. How small can we make them before it becomes too costly to implement? Obviously driving on the road is a great deal more complex than following tracks, but assuming we had the infrastructure, would it be feasible to have mini-trams that could carry a half dozen people at a time?
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Oct 3, 2010 18:12
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Cichlidae posted:How about we approach this from the other side? Driverless trains are commonplace these days. How small can we make them before it becomes too costly to implement? Obviously driving on the road is a great deal more complex than following tracks, but assuming we had the infrastructure, would it be feasible to have mini-trams that could carry a half dozen people at a time? I don't see why it wouldn't work in theory, but I don't think you can mix this type of traffic with our current unpredictable system. At that point, you're better off building your standard isolated light rail/subway/tram system. I don't see why you couldn't automate the trackless trollies that run around Cambridge and Watertown, but they go through busy city streets. Think of the chaos they'd have to deal with. Now, if all these things had electric motors powering every wheel with a kind of advanced brake system and some way to eliminate most of the steering system... you could do this on a normal car.
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Oct 3, 2010 18:25
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kefkafloyd posted:Of course, it has its drawbacks - witness the Toyota accidents. Plus a lot of good ole' fashioned fraud on top of that for good measure. (Why blame yourself or see your insurance rates raise when you can sue Toyota instead?) These are highly computerized cars with sophisticated black boxes; neither Toyota nor the government investigators could find a single case where the drive-by-wire was at fault. kefkafloyd posted:I guess my point is that steer or brake-by-wire isn't going to happen not for safety or insurance reasons, but because on the whole it's impractical and too expensive on such a small scale. On an airplane, the scale is so large that fly-by-wire makes a lot of sense. grover fucked around with this message at 18:58 on Oct 3, 2010 |
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Oct 3, 2010 18:55
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grover posted:The Toyota investigation discovered that the "unwanted acceleration" accidents unattributable to the floor mats were not caused by a failure in the drive-by-wire system, but by human error, and people pushing the gas instead of the brake. "The harder I pushed on the brake, the faster I went" indeed. I didn't mean to imply that the accidents were solely caused by the drive-by-wire system, but that the potential for flaws or bugs exist in these systems, and that these highlighted the potential. Even then, the black box systems in automobiles are nowhere on the scale of reliability or usefulness as the ones in aviation. If Toyota was an aircraft manufacturer, they'd be in hot trouble with the FAA over their actions (not necessarily what the data would reveal) Plus, you can't exactly "ground" a fleet of cars, as the NHTSA doesn't (as far as I know) have that authority. They can ban the importation of cars that do not adhere to standards, but that's pre-sale. The NTSB can only make recommendations on their investigation, and even their recommendations are up to the FAA to enforce in aviation. Obviously because the implications of an accident are, as mentioned earlier, on such a smaller scale than aircraft. There's no airworthiness directives for cars. Yeah, you can do a recall, but it's not on the same legal space as a federal grounding of aircraft. Though I'm sure if we wanted to give them that kind of authority, Congress could. Keep in mind that I'm on the side of throttle-by-wire, mind you - just trying to point out that the risks are still there, ableit minimal. Should have been a bit more precise about it. quote:Brake-by-wire is an integral part of every production hybrid-electric car on the planet. You can't have regenerative brakes without it. These cars have the infrastructure necessary to make this practical, though. Electric motor and hybrid cars require you to pay for that extra complexity already, so that stuff is already engineered into it. In a traditional car, there'd be probably little to zero benefit to brake by wire without redesigning the braking system (as seen in hybrid cars). ABS is computer controlled, yes, but a car with ABS brakes doesn't need brake by wire to function. Note that we're not really disagreeing on anything here, I just think people have a misconception on what a theoretical "drive by wire" car could do for them when the small scale systems on cars are still, for the most part, human strength operable.
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Oct 3, 2010 19:59
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kefkafloyd posted:I don't see why it wouldn't work in theory, but I don't think you can mix this type of traffic with our current unpredictable system. At that point, you're better off building your standard isolated light rail/subway/tram system. I don't see why you couldn't automate the trackless trollies that run around Cambridge and Watertown, but they go through busy city streets. Think of the chaos they'd have to deal with. It's called PRT.
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Oct 4, 2010 01:15
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FISHMANPET posted:It's called PRT. PRT systems are not at-grades with roads and separated from normal traffic. They're basically miniature rail systems and wouldn't be cross-compatible with the existing road network. That's not what chiclidae was asking about, at least, not what I read from his post. kefkafloyd fucked around with this message at 01:39 on Oct 4, 2010 |
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Oct 4, 2010 01:37
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kefkafloyd posted:These cars have the infrastructure necessary to make this practical, though. Electric motor and hybrid cars require you to pay for that extra complexity already, so that stuff is already engineered into it. In a traditional car, there'd be probably little to zero benefit to brake by wire without redesigning the braking system (as seen in hybrid cars). ABS is computer controlled, yes, but a car with ABS brakes doesn't need brake by wire to function. Brake-by-wire is actually more common than you think, and it's not just in hybrids. Many modern vehicles have ditched the mechanical proportioning valve altogether for electronic brake distribution - it, combined with the more advanced ABS implementations that are much more common now than 10 years ago, are needed to properly handle things like stability control and traction control. Hell, a smart braking system can do an impressive approximation of a limited-slip differential, and that technology has been in use for probably about 15 years. It's not a proper replacement, but it does mean that an open diff with one wheel on a tractionless surface isn't useless. Combine all of that with the electronic brake assist that's increasingly common as well, and I think may well be mandated in the near future by the government. Studies repeatedly show that even in the face of impending catastrophe, people just don't lay on their brakes hard enough, soon enough. A lot of cars now come with a computer that can detect what looks like a panic stop. In that situation, the computer ignores whatever partial brake pressure is being applied and clamps down full force. If nothing else it's an improvement in that you get full brakes the moment you touch the pedal, instead of the amount of time it takes for you to get full pressure on it. A small difference, but one that can matter. Also, just for shits and grins - an increasing number of cars have electrically-operated parking brakes. Steer-by-wire is already in place too, at least on some luxury cars. Look at all of the ones that can park themselves (albeit, badly). It's not just a matter of an electric motor moving the mechanical steering column and wheel, either. Either Lexus or Honda had to do a recall of their vehicles equipped with it because in a specific situation, the steering wheel would actually be 45* or more off of center while driving straight, until the computer recalibrated itself - that's a car with no default mechanical link between the wheel and the steering rack. Throttle-by-wire is old hat, but there are already adaptive implementations in place - adaptive cruise control will set a speed and automatically slow down when it can tell you've come up on slower traffic. In a nutshell, the controls that are required to do this are already in use. Not all are truly ubiquitous yet, but that's coming; power windows were a luxury at one point. The development that needs to happen is all in the computers that need to navigate based on these and handle the occasional exception. Failsafes in a car don't need to be on the same level of an aircraft; in a car, all you really need is the ability to maintain control while you pull off to the side of the road to a stop a few seconds later. I don't see anything approaching a fully automated car yet. I think the next logical step would be a car that can drive in a given lane as long as you want it to. I would pay just about any amount of money for a car I could navigate by myself into the HOV lane of the freeway, and then tell to follow that lane and give me an alert about 23 miles later when I actually need to get out of it again, and give me control at that point to drive the rest of the way in.
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Oct 4, 2010 03:08
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quote:Brake-by-wire is actually more common than you think, and it's not just in hybrids. Many modern vehicles have ditched the mechanical proportioning valve altogether for electronic brake distribution - it, combined with the more advanced ABS implementations that are much more common now than 10 years ago, are needed to properly handle things like stability control and traction control. Hell, a smart braking system can do an impressive approximation of a limited-slip differential, and that technology has been in use for probably about 15 years. It's not a proper replacement, but it does mean that an open diff with one wheel on a tractionless surface isn't useless. This is all fascinating stuff. I just thought it hard to believe that such things would be difficult to do economically in mass-production automobiles. Hybrids, luxury cars, I can understand because there's a price premium involved. I suppose to the end user really is the same thing as the hydraulics, but at least for brakes you can do all of this great safety stuff. Plus, it was only until fairly recently that power windows and locks were generally options. And yeah, they were a luxury until economics dictated they were cheaper to implement across the board. On the other hand... quote:Steer-by-wire is already in place too, at least on some luxury cars. Look at all of the ones that can park themselves (albeit, badly). It's not just a matter of an electric motor moving the mechanical steering column and wheel, either. Either Lexus or Honda had to do a recall of their vehicles equipped with it because in a specific situation, the steering wheel would actually be 45* or more off of center while driving straight, until the computer recalibrated itself - that's a car with no default mechanical link between the wheel and the steering rack. I thought these cars simply used electric motor power steering commandable by a computer in place of a traditional hydraulic system, but were still connected to the steering wheel via a mechanical column. I didn't think they were actually making production cars with it yet. To be fair, I don't really keep up with the luxo marques, I read what goes on in the performance area... and I'm sure those guys would think of steer-by-wire as anathema. Would there really be any benefit to steer-by-wire on non-luxury passenger cars that wouldn't have those auto-park features? Yeah, you can lose some weight by ditching the steering column, but... would the ordinary average car really get niceities like customizable steering feel? I suppose it's easier to argue for brake by wire with the safety things - where's the safety improvement in steer by wire? Could the computer use that in tandem with a stability system? Genuinely curious here,
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Oct 4, 2010 03:45
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kefkafloyd posted:Would there really be any benefit to steer-by-wire on non-luxury passenger cars that wouldn't have those auto-park features? Yeah, you can lose some weight by ditching the steering column, but... would the ordinary average car really get niceities like customizable steering feel? I suppose it's easier to argue for brake by wire with the safety things - where's the safety improvement in steer by wire? Could the computer use that in tandem with a stability system? There's already adjustable steering that's more sensitive at lower speeds and less sensitive at higher speeds, so that's one advantage. Linking the accelerator with traction control and the other systems could give some improved performance, as well. And isn't someone (BMW?) working on a concept car that only has one pedal, combined gas and brake? A setup like that would work best electronically. Of course, I'm a civil engineer, not mechanical, so don't expect too much insight from me. I'm learning a lot from you guys, though 
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Oct 4, 2010 03:52
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IOwnCalculus posted:Steer-by-wire is already in place too, at least on some luxury cars. Look at all of the ones that can park themselves (albeit, badly). It's not just a matter of an electric motor moving the mechanical steering column and wheel, either. Either Lexus or Honda had to do a recall of their vehicles equipped with it because in a specific situation, the steering wheel would actually be 45* or more off of center while driving straight, until the computer recalibrated itself - that's a car with no default mechanical link between the wheel and the steering rack. It was the Lexus LS. Video: https://www.youtube.com/watch?v=zVxGH4zl6zU Can you tell me what these are that have started showing up on I-71 and I-480 (at least)?  They seem to be radar drones of some sort, as I've started getting a lot of K-band falses on the highways where these are which correspond with where the obvious directional antenna is pointed. What's odd is that they're shooting at very strange angles, often aimed from a sign on the NB side pointing at the SB lane 1/2 to 3/4 of a mile south of the sign.
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Oct 4, 2010 03:56
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Like I said, my expertise is in aviation, not automobiles, so my base of knowledge comes off large scales. I'm learning a lot too. I'm a car enthusiast but I'm still more of an end user than an expert.
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Oct 4, 2010 04:01
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wolrah posted:It was the Lexus LS. Video: Looks like a speed detector to me. Around here, they're installed by third parties who then sell the data to the state DOT and, presumably, to online traffic sites. Those speeds can be used to calculate travel time and show real-time congestion maps. It could be pointing perpendicular to the tube in your situation. They can easily differentiate between speeds in different lanes, so they usually are aligned perpendicular to traffic. Then again, the ones we have here are squares, not tubes, so it could be a different design.
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Oct 4, 2010 04:11
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I am a bit  about these cameras and I finally found this explanation. http://vbgov.com/vgn.aspx?vgnextoid...nextfmt=default The city calls them Machine Vision cameras which help guide the timing at traffic lights. Can these record video or is just a stream of data that is interpreted by the traffic light? How do they work? I know the site says it doesn't record the video, but they are freaking everywhere now. Thanks.
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Oct 4, 2010 19:30
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AIIAZNSK8ER posted:I am a bit
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Oct 4, 2010 21:32
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AIIAZNSK8ER posted:I am a bit Those are just video detection cameras, according to the link. They're not sophisticated enough to record video at definitions that would allow license plate reading. The cameras just pick out a detection area and return more or less a binary signal of "car" or "no car" to the controller, like a loop. I suppose in theory they could detect when someone runs a red light, but they'd have no way of proving who it is or communicating it to the police. Remember, signal controllers are VERY stupid. Edit: GWBBQ posted:Here in Stamford they have old-style and PTZ domes all over and they said they're to help monitor traffic flow and that the city DOT can look at them, but they're not used for enforcement. Those lights aren't for detection at signals, they're for traffic monitoring and to help respond to accidents. Those cams have direct feeds to the Bridgeport operations center, and they can zoom in enough to get your license plate if needed. However, they're not used for enforcement, just monitoring. You can flip them off, speed in front of them, pretty much anything short of performing a terrorist act in front of them, and nobody will care or try to hunt you down. Cichlidae fucked around with this message at 21:50 on Oct 4, 2010 |
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Oct 4, 2010 21:48
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kefkafloyd posted:This is all fascinating stuff. I just thought it hard to believe that such things would be difficult to do economically in mass-production automobiles. My car has ESP, and that's a fairly low end 7 year old compact. I don't know how common it it in the states, but it's almost ubiquitous in Europe. I think if we are going to see innovation along these lines it's likely to be in America though. Over here we'd be more likely to put money into improved public transport.
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Oct 4, 2010 23:17
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