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Is Your GPS Naive?
Posted by
CmdrTaco
on Sun Apr 22, 2007 12:41 PM
from the what's-a-dikfor-anyway dept.
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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An even better application: (Score:5, Insightful)
Social hack - use "bullfight" for "speed trap". (Score:5, Funny)
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Re:Social hack - use "bullfight" for "speed trap". (Score:5, Insightful)
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Re: (Score:3, Insightful)
Re:Social hack - use "bullfight" for "speed trap". (Score:5, Insightful)
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...
Parent
Re: (Score:3, Insightful)
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
Re:Social hack - use "bullfight" for "speed trap". (Score:4, Informative)
If we assume that each road will have a speed trap on it at least once, then they've *already got* the data to determine an appropriate speed limit as per the 85th percentile rule [ite.org]. Interestingly, as Wikipedia [wikipedia.org] notes, "a review of available speed studies demonstrates that the posted speed limit is almost always set well below the 85th-percentile speed by as much as 8 to 12 mph (see p.88) [trb.org]." This indicates that in a vast majority of cases, speed limits are set according to political rather than safety concerns.
Parent
Re: (Score:3, Informative)
Highway speed limits were originally instituted to save fuel. If you drive between 55 and 60 on the highway you'll get about 10% better gas mileage. Having had to drive 40 miles each way for work each month, I figured this out very quickly.
Re: (Score:3, Informative)
Re:Social hack - use "bullfight" for "speed trap". (Score:4, Insightful)
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.
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Re: (Score:3, Insightful)
Re:Social hack - use "bullfight" for "speed trap". (Score:5, Insightful)
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.
Parent
Re:that's not what they told me (Score:4, Informative)
That being said - I usually drive the speed limit exactly (65 usually) since its better for fuel efficiency than doing 75, 85, etc.
Parent
Re: (Score:3, Informative)
you should probably be a little more careful about who you're repying to when throwing around "your type are assholes" respo
you're the problem (Score:5, Insightful)
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.
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Re:that's not what they told me (Score:4, Informative)
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Re:Social hack - use "bullfight" for "speed trap". (Score:4, Interesting)
Because you're putting everybody else at risk more than he is? Or was that a rhetorical question?
Me, I'm personally happy to cruise along in the righthand lane in my non-aerodynamic vehicle that is lucky to go 75 downhill with a tailwind. For some reason going out of my way to break the law, annoy others, and risk my own safety for no reason whatsoever just never occurred to me.
Parent
Re: (Score:3, Insightful)
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!
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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.
Speed-laws are not reasonable (Score:5, Insightful)
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...
Parent
But you agreed to stick to them (Score:4, Insightful)
OK, unfair/discriminatory/whatever, sure. But "ripping others off"? Did they break the speed limit or didn't they?
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.
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).
Parent
Re: (Score:3, Interesting)
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 (unde
Re:Social hack - use "bullfight" for "speed trap". (Score:5, Insightful)
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.
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Re: (Score:3, Funny)
I've done 100mph in a 30 zone.
Driven at 8x legal alcohol.
Overtaken in the wrong lane.
Fallen asleep at the wheel.
Done 140mph on the motorway (70 mph limit).
Driven under the influence of drugs.
Driven 10 miles to work using peripheral vision only.
Taken part in street races.
And I have 0 tickets (except for 2 parking tickets) and NEVER caused an accident.
What's your point ?
Re:Social hack - use "bullfight" for "speed trap". (Score:4, Funny)
Adjust your driving accordingly.
Crown Victoria (2006/2007 models)
max speed 120/130mph (dependant on gearing)
0-60 8.7 sec
Highway - open, available exits
If you're traveling at 60mph, it would take them about 15 seconds to match your speed (leaving the side of the road). That puts 1/4 mile between you and the patrol car before speed is matched.
If you're traveling at 120mph, it would take them about 15 seconds to get to 60mph, at which you're already 1/2 mile away. It's an unknown period before they reach max speed, but most sedans of that size that I've driven, the top end is tough. Say another 30 seconds to pass 100. You're more like 1 mile away.
But, when you see the patrol accelerating hard to match your speed, do you slow down? You could. You're going to get a ticket.
Push it up to 150. Now there will be no closing speed. The gap will always get larger. Then take the exit of your choice when you're out of view, and taken an alternative route.
Of course, this is the day you're wishing you hadn't bought a fire engine red Ferrari, driving through Sticksville.
If you're driving a common-enough looking car, you're home free. If you're driving something half-way unique that couldn't be identified when you passed his stopped patrol car at 120mph (what'd that bumper sticker say?), there's nothing to really worry about. It won't necessarly be him looking for you. Ya, radio
People are generally law abiding. They hit the brakes when they see the cop, and pray to not get the ticket. It doesn't matter. He already got you on radar. You're still screwed when you stop. Well, assuming he catches up with you.
Don't be the idiot on cops though. I love the ones who get in a one-car wreck running from the cops. Those are people who shouldn't have been driving anywhere near as high as the speedlimit in the first place.
Parent
Re:Social hack - use "bullfight" for "speed trap". (Score:4, Informative)
They should come here across the pond to introduce themselves to the most recent inventions in motorist taxation like:
The "Accident Assistance Van" and "Yellow Speed Camera Partnership Van". Both are in use by Sussex police and anyone driving along the A14 and A12 can see them on regular basis.
These vans can be parked with a laser speedgun + CCTV pointed through a window (back, side and front), can be parked behind a hedge with the same laser speedgun + CCTV as the only thing visible on a tripod cabled to the hidden van and most importantly can drive at 3 mph under the speed limit and record the speeds of all who overtake them showing van speed and overtaking vehicle speed.
I have seen them used in every single one of these modes of operation. In fact, out of all my A14 journeys in the last month there has been only one where I have not seen one them. None of them has proper police markings.
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Re: (Score:3, Insightful)
Re:An even better application: (Score:5, Funny)
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Now, why would there be... (Score:4, Insightful)
Re:Now, why would there be... (Score:5, Funny)
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Re:Now, why would there be... (Score:5, Funny)
I mean, informing people about terrorist attacks is just playing into their hands.
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The evil bit (Score:3, Interesting)
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The idea, James, is that people could nefariously disrupt the public with messages designed to cause hysteria.
Re:Remember Boston (Score:5, Funny)
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They'd merely alter their route so they could meerkat the carnage as they drove past. Heavens Forbid that they miss the chance to see such a disaster with their very own eyes, driving past at 10mph looking to the side rather than straight ahead. Wow, is that a dead body? That's something to tell the kids tonight!
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RDS exists to allow FM radios in cars to do fun stuff like retune to a national station as you move around and the frequencies change. It also allows radio broadcasts to be flagged as "traffic" so your radio can automatically tune in and play traffic broadcasts to you.
In other words, its function is to usefully and automatically tune your FM radio to a new frequency.
The NBC "terrorism" broadcast flag is designed so that in the godawful scenario whe
Alternatives (Score:2, Funny)
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Advertising tool... (Score:2)
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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.
Re:Advertising tool... (Score:4, Insightful)
Parent
encryption cant help.. (Score:5, Insightful)
Re:encryption cant help.. (Score:4, Interesting)
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"Off the shelf" (Score:2)
There are plenty of extremely simple radio transmission that would be even easier to hack. One that comes to mind are the (rather dated) tones broadcast locally to set off EMS / Fire pagers. Another would be the National Weather Service alerts.
Dan East
Sounds familiar... (Score:5, Interesting)
This could be useful (Score:3, Interesting)
Re: (Score:2, Informative)
Re:IT'S SPELT NAÏVE! (Score:4, Funny)
This is been a lesson in nitpicking, you fucker.
Parent
Re:Shouldn't this have been tagged with HAHA alrea (Score:3, Insightful)