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Hardware Hacking

Is Your GPS Naive? 291

Posted by CmdrTaco
from the what's-a-dikfor-anyway dept.
mi writes "Many GPS devices today will try to scan the FM bands for traffic advisories in the area to display on their screens. The signals, however, are neither authenticated nor encrypted, and one can — with commonly available electronics — construct a device to broadcast bogus advisories. Possible codes range from "bullfight ahead" to "terrorist attack"..."
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Is Your GPS Naive?

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  • by Ph33r th3 g(O)at (592622) on Sunday April 22, 2007 @12:44PM (#18832863)
    "Speed trap ahead."
  • by jamestheprogrammer (932405) on Sunday April 22, 2007 @12:48PM (#18832899)
    Why would you have a "terrorist attack" code for a traffic warning system? Okay, so I can see how maybe they might close off streets for emergency personnel, but couldn't you just leave the code at that - "Roads Closed"? I mean, if you go telling drivers that there's a terrorist attack ahead of you, they're going to panic, freak out, and maybe get into a car wreck.
  • by vasanth (908280) on Sunday April 22, 2007 @01:01PM (#18832973)
    the writer seems to think encryption can solve this problem, encryption cant help here as the system is unable to communicate back to negotiate the setup, and if the signals are encrypted with a predetermined key it will be susceptible to replay attacks... how different is this to a common radio channel telling its listeners that there's been a terrorist attack etc? the issue seems to be more of a hype than a real concern...
  • by zCyl (14362) on Sunday April 22, 2007 @01:19PM (#18833103)

    But I can also see this becoming an annoying advertising tool.

    I doubt it. You can also broadcast bogus FM radio station signals containing your own advertisements, because News Flash: FM radio is also not authenticated.

    But in the U.S. the FCC regulates these sort of things, and would not take kindly to you broadcasting all over the spectrum without authorization.
  • by Dun Malg (230075) on Sunday April 22, 2007 @01:43PM (#18833273) Homepage

    Years ago (going on 30 years ago, now), I used to hitch-hike. It was safe then.
    Please. It's still just as safe as it always was (i.e. perfectly safe, unless you're unlucky or alone and female). You think the odd itinerant serial killer didn't used to pick up and murder hitchhikers in the 70's? I can cite you DOZENS of hitchhiker murders from the 70's. The only difference now is that you hear about it on the news, and advances forensic science have led to more conclusions of "definitely murdered hitchhiker", rather than the old separate results of "family in Oregon never hears from hitchhiker again" and "police unable to ID body found by Hwy 8 in Ohio".
  • by Anonymous Coward on Sunday April 22, 2007 @02:16PM (#18833477)
    Ambulances are dispatched. If they are responding to a terrorist attack, they would have been given a location and would know why there would be a 'road block'. Its like saying that an ambulance can't respond to an accident because the roads around the incident were stated as being closed off.
  • by portforward (313061) on Sunday April 22, 2007 @02:41PM (#18833661)
    Or alternatively, you could just drive the speed limit.
  • by icebrain (944107) on Sunday April 22, 2007 @03:53PM (#18834237)
    Or, they could make the speed limit reasonable, instead of setting it to nonsensically-low numbers just to raise revenue.
  • by springbox (853816) on Sunday April 22, 2007 @04:33PM (#18834529)
    Contrary to the opinion of nearly every jerkwad driver on the interstate, approaching 100 MPH is not "reasonable" or safe.
  • by icebrain (944107) on Sunday April 22, 2007 @05:02PM (#18834723)
    I never said 100mph was safe or reasonable... but there are many, many places where the road can (and does, every day) handle traffic safely at 70-75 instead of the posted 55, or 45-50 instead of a posted 35 (excluding residential areas). Many of these restrictions are due to arbitrary laws that say, in essence, "speed limits must be X within Y miles of a city", with no regard to the actual road or what it could safely handle.

    Look up the video sometime of when a bunch of college students lined up across I-285 in Atlanta and did the posted speed limit (55). Traffic backed up for MILES behind them.

    A much bigger threat than pure speed is people who don't pay attention, and realize "Oh crap, that's my exit, four lanes away!" and proceed to cut across said four lanes. Or those who don't bother to check their blind spots when changing lanes, or don't realize that their lane is ending, or don't signal... or insist on driving slow in the left lanes.

    And again... if the purpose of limits really was to promote safety, cops wouldn't have to hide. And there would be no penalty for warning others of a speed trap, either. They don't arrest you for saying to someone, "don't rob a bank, the police will get you!" so why should saying "don't drive fast, you'll get a ticket" be any different? Oh, wait, then the local government won't get its traffic fine revenue... and God forbid that the residents pay for their government themselves...
  • by Dun Malg (230075) on Sunday April 22, 2007 @05:29PM (#18834929) Homepage

    This does show how unreliable the GPS system is.
    No it doesn't, you dunce. This hack really has fuck-all to do with GPS. It's a hack of the TMC protocol, which is a terrestrial FM radio signal.
  • by ozbird (127571) on Sunday April 22, 2007 @06:41PM (#18835385)
    The problem with the speed limit is that it's been fixed since the 70's (55mph in a whole heap of places) while vehicles have continued to improve (safety and handling-wise).

    Pity drivers' ability and attention span haven't kept pace...

    Having seen umpteen people chatting on their cell phones, travelling well in excess of the speed limit on the Beltway around D.C. and oblivious to their surroundings - and the accidents and near misses that result - 55mph seems a perfectly reasonable limit to protect such drivers from themselves.
  • To that end, not much brings a smile to my face more than driving at the speed limit on cruise control (which I always do) in the passing lane, and pissing-off some Type-A driver ... for it by breaking the law.


    Of course you realize that you, too, are breaking the law. Yielding to faster-moving traffic in the leftmost lane is required by law in most states -- it makes no difference whether you think the other person is going "too fast", you're still causing a safety hazard, and I know several cops who love to give out tickets to people who are causing unnecessary hazards like that.

    The speed of safe travel is not an absolute thing, when you're dealing with groups of people the safest speed to be traveling is "however fast everyone else is going", even if it is in excess of the posted limit, and traffic laws do generally reflect that.
  • by icebrain (944107) on Sunday April 22, 2007 @07:17PM (#18835567)
    Slow drivers in the left lane probably cause more multi-car (ie, besides themselves) accidents than speeders do, because it forces so many people to slow down, dodge them, change lanes, etc. I've seen plenty of near-accidents caused by a slow person in the left lane, but I have never seen one caused by someone merely driving fast on a road that could support it (assuming they didn't do something stupid, like weave between traffic or cut someone off). I see no harm in letting someone going faster pass you on the left, but trying to take it on yourself to be a traffic enforcer may very well be putting your life in danger. I was once riding in a rear-facing station wagon seat when the driver decided to do the speed limit in the left lane in Atlanta, and I have never felt more scared in my life, seeing all of those cars fly at me and dodge at the last second.

    I'd like to try something with people that insist the speed limit is always right. I'd like to take several minutes of video (shot from a driver's perspective) on different roads where traffic routinely exceeds the limit by a significant amount (10+). Black out the speed limit signs, and play it to those people. Ask them if they feel that traffic is moving too fast, or at a good speed. If they say it's moving at a decent speed, tell them the actual speed limit and see if they change their minds. (alternatively, cover the signs up, then have them drive the course and see how fast they go. this probably won't work if they're familiar with the area, though.)

    As far as getting such things changed, many of us have tried to talk to the pertinent elected officials and such. However, it must be something in the water at the city council buildings (and I guess this is true of all governments, regardless of size), since once they get elected, the will of the populace that elected them seems to be completely forgotten. Very few city councils are going to want to raise speed limits to reasonable values because they don't want to give up the revenue stream.

    I propose that all money from certain miscellaneous traffic offenses like speeding, seat belt violations (for adults only, not children), and red light cameras, be collected into a national- or state-level fund. The money would be held in an account, and only disbursed for certain good causes (disaster relief, maybe, or scholarships, or something like that). The idea is that we need to remove the financial incentive for local governments to issue such citations. The money needs to be placed completely out of their reach, with no possible way for them to get hold of it directly, or they just see it as a treasure chest. Maybe then, they will start enforcing for safety rather than revenue.

    I've never been to Germany, but as I understand it, they don't have nearly as many problems with accidents on their autobahns, and their speed limits are much higher. Then again, in order to drive you have to actually prove that you can. Here, the driver's test is little more than "can you go around the block without hitting anything?" There are millions of people out driving in this country that really shouldn't be driving anything more than a bicycle, like the lady who was going down the highway behind me two weeks ago, _reading_a_book_ while she was driving. I'm thinking it's easier and cheaper (not to mention more lucrative) for governments here to set low limits for everyone, in the hope that the stupid drivers will survive their accidents, rather than make the driving standards tougher.
  • by mi (197448) <slashdot-2014@virtual-estates.net> on Sunday April 22, 2007 @07:51PM (#18835769) Homepage

    If you have an issue with the speed limits in your town, please contact your local elected officials. Have you ever been to a city council meeting?

    In too many localities police will usually let a local resident off with a warning while ripping others off. This keeps local residents (who attend council meetings) content, and brings easy revenue (people from afar are very unlikely to challenge the tickets in local court) to the town. This selective enforcement gets documented occasionally and is a real bane of highway travel.

    NJ's Governor Corzine just had a nasty accident [yahoo.com], because his driver (a State trooper, no less) was going 91 in a 65 mph zone (Governor's vehicle can only do that in an "emergency"). The governor will take months to recover, because the moron was not wearing his seatbelt. Neither the hypocrite trooper (who had a similar accident a few years ago), nor the hypocrite governor are expected to be punished by law, although tens of thousands drivers are fined in NJ for the same (and lesser) offenses every year — most of them without causing an accident.

    The speed laws are not reasonable — they take neither car's age and quality nor the driver's experience and health into consideration. What's too fast for an inexperienced 17- or half-blind 70-year-old driving a Buick is unreasonably slow for a healthy middle-aged driver driving a BMW...

  • US 20 here in Ohio has a few areas where it's a 4 lane divided highway, all but identical to Interstate 80 a few miles north, but the speed limit is 45 for no good reason. Corn fields on the right, corn fields on the left, nothing but fucking corn and the ever-present Highway Patrol cars in the median. Along the same route there are also some useless speed trap towns where the speed limit is 25 because one house happens to be close. Again, this is on a 4 or sometimes 5 lane highway and of course there are almost more cops than residents in these towns.

    I don't care where the road runs, speed limits should be set by taking a normalized average of the speed people drive on it and then rounding to the nearest 5. On I-80, this would put the limit at either 80 or 85 and the majority of US 20 at 65 or 70, dropping down to 45 or 50 in the towns. There's no reason any marked road should have a limit lower than 35, nor should a 4+ lane road ever go below 45.
  • by Firethorn (177587) on Sunday April 22, 2007 @09:15PM (#18836237) Homepage Journal
    If every on the interstate is going 70 and the posted limit is 55, driving 70 is dangerous.

    I think that you meant drive 55 would be dangerous

    Studies have shown that differences in speed are more dangerous than high speeds alone.

    If everybody else is doing 70, you're safest doing 70 as well.
  • by icebrain (944107) on Sunday April 22, 2007 @09:20PM (#18836279)
    Training should be something like what you go through to be a pilot--you aren't allowed full privileges until you've proven you know how to handle things. Granted, there are still stupid pilots out there, but the percentage is much lower than for drivers.

    I think the reason so many people get short fused when driving is that they get nervous. And they get nervous because they can't process things fast enough, or multitask well enough. They lose situational awareness (SA), which is essentially the knowledge of what's going on around you (or they never develop any SA to begin with). Any fighter pilot will tell you that losing SA in combat will get you killed--quickly. Losing it on the road can do that, too. And to top it off, many people just don't have the coordination or reflexes to handle machinery like this. They have to consciously think about controlling the car, modulating their pedal inputs, and basic driving.

    To jump back to the flying example: When I started flying, I could only keep track of a few things at a time. I sometimes missed things, and probably survived a couple things just by luck. Just making the airplane go where I wanted it to was a conscious effort. Even getting to this point took 45 hours of instruction, practice, and studying. I got the license, but didn't do much flying on my own for a while.

    Then, my dad and I finished building our airplane. It was a much higher-performance model than what I was flying before (think tuned sports car vs. a Camry), but there were some critical differences: our plane is more responsive, so it doesn't have to be manhandled around like the old Cessna did; it has a bubble canopy instead of car-like windows (easier to look around), and my "instructor" was much more experienced (my dad has 10k+ hours). I started flying with him every chance I got.

    Then one day, something changed. I realized that I didn't have to consciously think about how to fly the plane any more. Instead I could just make the plane go where I wanted it to as an extension of myself, leaving my higher mental functions able to keep track of where all the _other_ airplanes were, where I was, and what was happening around me. Now, after 150 hours of flying, I can lead a four-ship formation around, handle the radio communications, navigate, and still fly the airplane. And even then, I'm required (like all other pilots) to have some form of recurrent training or examination at least once every two years (or more often, depending on what you fly). It's actually gotten to the point where I find flying easier than driving, and I have a lot more experience with the latter. There are fewer idiots in the air, because the system catches them and keeps them on the ground. Pilots don't fly in bad weather until they get the specific training and checkride that they need to do so (well, a few try, but the results are usually fatal).

    The lesson applies to driving, too. It takes time and good instruction before someone is really capable of handling everything that comes at them on the road. Ideally, Unfortunately, the vast majority of people never get that instruction or experience, they don't learn from it, or they just physically can't handle it. And I guess therein lies the conundrum. Cars are nearly essential in this country, unless you live somewhere with good public transit, and making it harder to get a driver's license means a lot of people will be stuck with no way to get to work or the grocery store. On the other hand, making the driving test so lax that nearly anyone can pass also puts a lot of lives in jeopardy unnecessarily. Which one is more important to you? I certainly don't know.
  • Translation (Score:1, Insightful)

    by Anonymous Coward on Sunday April 22, 2007 @10:13PM (#18836637)
    You sure took a lot of words just to say "I am an asshole".

  • Do you have any idea how bad an idea it is to break other traffic laws to enforce the speed limit?!
    Speed limits are somewhat arbitrary. Getting out of the way of someone who wants to pass you is prudence. You do not want someone hitting your rear bumper at 80 mph!
  • by Namarrgon (105036) on Sunday April 22, 2007 @10:23PM (#18836685) Homepage

    police will usually let a local resident off with a warning while ripping others off

    OK, unfair/discriminatory/whatever, sure. But "ripping others off"? Did they break the speed limit or didn't they?

    a real bane of highway travel

    I would have said "unsafe drivers" were more of a real problem. A ticket when you break the speed limit may be annoying, but having your family wiped out by (e.g.) a drunk driver or a trucker pushing his alertness limits or a speeding NJ Governor, now THAT's a problem.

    The speed laws are not reasonable -- they take neither car's age and quality nor the driver's experience and health into consideration.

    True enough. Of course, it gets complicated if you try to write legislation that codifies something as subjective as car quality and driver experience. The commonly accepted approach is to set the limits at a reasonably low average and to let the cop use his/her discretionary judgment. Perhaps your own car or apparent experience are not sufficiently reassuring - or perhaps the cops have just seen too many middle-aged corpses in wrecked BMWs.

    You & I can argue about where the limits are set, but it's pointless. The roads are common property, the rules for sharing them are the rules we agreed to abide by when we got our licenses, and there really aren't many times when one simply must drive that fast (hint: they usually involve sirens and flashing lights).

  • you're the problem (Score:5, Insightful)

    by nanosquid (1074949) on Sunday April 22, 2007 @10:27PM (#18836707)
    They said you do not have any obligation to move or go faster than the speed-limit whatsoever.

    Your primary obligation is to drive safely and avoid accidents. In most cases, that means that you don't have to go faster than the speed limit, but you still have to heed "slow traffic keep right".

    Honestly, I think your type are assholes.

    I stay with traffic flow, and I haven't gotten a moving violation in the 20 years I have had a license. And if you drive too slow in the left lane, I keep a safe distance.

    Nevertheless, I have my opinion about people like you, and let me say: you're the asshole. It's people like you who put some intellectual game ahead of the safety of people around them. You know full well that you will get some bumper-hugging type-A personality behind you who doesn't keep safe distance from you, and when you two have an accident on the highway, you're going to take other people with you and block traffic for hours. You're just as much a "type-A" personality as the person who speeds, and you're just as dangerous. It's just that you're passive-aggressive instead of simply aggressive.

    The only safe thing to do is that if the guy behind you isn't keeping a safe distance, you get out of the way. If you don't, you endanger yourself and everybody around you needlessly.
  • by metamatic (202216) on Sunday April 22, 2007 @11:31PM (#18837051) Homepage Journal

    It's funny that you say that. I've been legally driving for 18 years (and a few before that, shhh). I've managed to be in 4 car accidents. I take speed limits to be a guideline of how fast I should be driving. Knowing the max speed is 65mph on a highway, but having effectively unlimited visibility ahead of me and empty roads, I tend to go faster. Lets say more than 50% of my driving has been over the speed limit.

    The 4 accidents I've been in have all been low-speed accidents (under 40mph). 3 of which were driver or vehicle failure ahead of me.

    1) Bumper tag between 4 cars ahead of me. Unable to stop for the suddenly stopped vehicle ahead of me.

    [...]

    3) Truck, no brake lights, locked up tires rear-ended stopped vehicle ahead of him. Unable to stop.

    So in 2 of your 4 accidents, you were driving too fast, and were unable to stop when something bad happened in front of you. Hence, you rear-ended someone. Presumably the insurance company held you to be at fault. You might have been driving at low speed in absolute terms, but you were clearly driving too fast--or leaving inadequate stopping distance, if you want to look at it that way.

  • by thefirelane (586885) on Monday April 23, 2007 @03:28AM (#18838063)
    And there would be no penalty for warning others of a speed trap, either. They don't arrest you for saying to someone, "don't rob a bank, the police will get you!" so why should saying "don't drive fast, you'll get a ticket" be any different?

    Do you honestly not understand the difference? Telling someone to drive the speed limit is still legal... however, you are warning people who are already breaking the law, that they will be caught.

    I assure you, if someone already has robbed a bank, and you tell them to go a certain way to avoid a cop... you will be prosecuted.
  • by mysticgoat (582871) on Monday April 23, 2007 @09:51AM (#18840233) Homepage Journal

    Pity drivers' ability and attention span haven't kept pace...

    Mod parent up.

    Sane speed limits are based on the limits of human reaction times, the physics of inertia and friction, and patterns of traffic density, types of vehicles, and frequency of exceptional events (like toddlers chasing after balls that bounce into the street). Since signage cannot be changed on a minute by minute basis, posted speeds are often lower than what would be safe for the moment. That does not make them unreasonable, nor does it suggest that the driver, from his very limited point of view, should be deciding when he can break the speed limit and get away with it.

    If and when a slashdot reader gets a license to drive, it binds him to a social contract that requires him to accept these limits. If he violates that contract, he needs to face sanctions. Those around him should also take note that this person does not abide by his agreements and is a risk in other areas, such as employment agreements, production of code that is free of time bombs and backdoors, etc, etc.

  • by operagost (62405) on Monday April 23, 2007 @10:44AM (#18841019) Homepage Journal
    Makes you wonder why Magnum, P.I. bothered with a Ferrari at 35 MPH.
  • by irc.goatse.cx troll (593289) on Monday April 23, 2007 @01:12PM (#18843057) Journal
    I think a better use of technology would be having speedlimits broadcasted so you could know. A lot of times the signs will be be hidden behind a big overgrown tree or bush, or purposely hard to see. If your car could just alert you that you're approaching the speed limit (and preferably only you, and not do anything other than sound a buzzer and light something), I think there would be less accidental speeding.

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