Follow Slashdot stories on Twitter


Forgot your password?
Canada Privacy Transportation

Bluetooth Used To Track Traffic Times 133

First time accepted submitter ChanukahZombie writes "The City of Calgary, AB has introduced a new traffic congestion/timing information platform for drivers. 'The system collects the publicly available data from Bluetooths to estimate the travel time and congestion between points along those roads and displays the information on overhead message boards to motorists.' Currently only available on the Deerfoot Trail (the city's main highway artery) but will be 'expanded in the future to include sections of Crowchild Trail and Glenmore Trail in the southwest.' As for privacy concerns, the city says it cannot connect the MAC address collected to the device owner."
This discussion has been archived. No new comments can be posted.

Bluetooth Used To Track Traffic Times

Comments Filter:
  • As for privacy concerns the city says it cannot connect the MAC address collected to the device owner.

    Until they arrest someone and subpoena any data related to that person's MAC. Then they've got a nice bit of tracking data.

    • by Mashiki ( 184564 )

      The city is bound to the privacy act in this case. And in turn, they won't be able to subpoena the information related to the mac without showing that an actual crime was committed. That would be a fishing expedition in Canadian law. And both the Superior Court, and SCC would flush this down so fast that any Crown who tried it would still be reeling from the blow.

      I have to say though, having driven along all of these routes, especially Deerfoot Trail and Glenmore Trail, this is welcome and needed badly.

      • And in turn, they won't be able to subpoena the information related to the mac without showing that an actual crime was committed.

        So, I guess if you carry a bluetooth device and commit a crime, you are hoping that nobody commits a crime that the police can show actually was committed so they can subpoena MAC data for.

        If you commit a crime that isn't a crime, what is the sound of one hand being handcuffed?

        • by Mashiki ( 184564 )

          Doesn't work like that here. You'd only be able to subpoena for the mac of the specific device, not all devices.

          And if you commit a crime that isn't a crime, you're committing a violation not a crime.

          • Doesn't work like that here. You'd only be able to subpoena for the mac of the specific device, not all devices.

            If you already know the MAC, you don't need a subpoena to find out the MAC.

            And if you commit a crime that isn't a crime, you're committing a violation not a crime.


            • by Mashiki ( 184564 )

              If you already know the MAC, you don't need a subpoena to find out the MAC.

              Not how it works in law up here.


              Glad you don't know the distinctions of law in Canada either.

              • Not how it works in law up here.

                So the law in Canada is a moron? Why the hell would you need a subpoena to find out the MAC address when you ALREADY KNOW THE MAC ADDRESS?

                Glad you don't know the distinctions of law in Canada either.

                That "whoosh" is the joke about committing a crime that isn't a crime and the sound of one hand zipping past your touked head, eh?

      • Edmonton has the same problem too, bro. The Whitemud and Yellowhead are clog factories. 75th street, never intended to be a main artery, feels like you're driving through some third world place.The Henday helps, but is only two lanes wide and easily and frequently gets backed up. With the tailgating that goes on everywhere, it just takes one person to hit their brakes and it causes a chain reaction lasting several minutes. This morning I watched a guy almost plow into someone's ass there. There is no more r

        • by Mashiki ( 184564 )

          Yeah I agree it's pretty bad. The real problem is there's no easy fix for it. The boom came out of nowhere really, even places like Grande Prairie are very quickly becoming a mess with the massive influx of people and don't get me started on Lethbridge either. 5am GP is like 5am Kitchener-Waterloo now with everyone hitting the commuter flights to fly into Edmonton and Calgary simply to avoid the traffic.

    • There is nothing to subpoena. This particular device does not store MAC addresses at all. When a Bluetooth device is detected, the first thing that is done is to pass the MAC through a one-way hash. The actual MAC address is immediately discarded and only the hashed value is stored.

      • by The Bean ( 23214 )

        So, when you have someone you wish to track, you take their MAC address and run it through the one-way hash. Boom, tracking acquired!

  • by aNonnyMouseCowered ( 2693969 ) on Wednesday November 28, 2012 @08:27PM (#42124873)
    TFA is low on details re: what Bluetooth devices are being monitored. I know my cellphone and laptop have Bluetooth support, but I keep that mostly turned off. Do all cars in Canada come with built-in Bluetooth tracking technology? Triangulating from actual cellphone signals appears to me to be a more fool-proof if not spook-proof technology. The limited range of BT devices do make them a better choice in terms of privacy.
    • by zerro ( 1820876 ) on Wednesday November 28, 2012 @08:31PM (#42124907)

      You don't need to monitor every bluetooth device. You just need a decent sampling of users passing through points in your "system". This is just one of several ways you can uniquely identify a particular object to track overall flow of the herd.

      • by AmiMoJo ( 196126 ) *

        You would be surprised how many you can pick up too. A while back the place I worked bought a Bluetooth spamming machine that tried to send messages to any device in range. We had a few hundred hits an hour as people drove past the shop, and it wasn't even on a particularly busy road.

        I wonder how sustainable it is though. Most new devices make sure they are not discoverable until you push a button to make them visible for a minute or two. In ten years time it might not work so well.

        I'd love to see an open s

    • by wbr1 ( 2538558 )
      Any on devices. Pretty simple really, scan for bluetooth devices at points a,b,c. See devices x,y,z pass at times t1,t2,t2. Solve for speed since distance is known. Viola, congestion report. And a handy database of MAC addresses. Sure, they cant tie them to specific devices now, but subpoena the manufacturer, seller, or after an arrest, and you do have a tracking mechanism for people. However, post warrant/arrest, most people already have a tracking device in their pocket. A mobile phone.
      • OMG this is slashdot. How can you people not know that MAC addresses are as transient as IP addresses?!? If you own the entire network you're operating in, then yes, you can be relatively sure that a mac address is real, but on a public network? No way in hell. Most network cards allow you to change mac addresses at will, most android devices as well. I have a Bluetooth audio receiver that I bought several of because it was really handy. Unfortunately I can't use them anywhere near each other because they a

        • Can someone impersonate your car's or phone's BT MAC address? Yes. Does the average person have the knowledge and ability to do so? No.

          So, if the government database shows that a BT device with a MAC address matching that of your car or phone was on Deerfoot Trail at 2am on Monday, then it is likely, but not certain, that your car or phone was on that road at that time. Note that the presence of your car on phone on the road does not mean that you were there. Similarly, the absence of your car's or phone's

          • What is an "expert hacker"??

            Apparently someone with a rooted phone that can download a single file and type:

            > adb push wlan_config /data/local/tmp/
            > adb shell chmod 777 /data/local/tmp/wlan_config
            > adb shell /data/local/tmp/wlan_config --dry-run bt=

            Mac Address changed. What's your mac address? I might take a trip up to Canada and get you some speeding tickets...

        • by plover ( 150551 )

          Don't panic. It doesn't matter for this application if your phone is tied to your identity. All they care about is if the average times of devices detected that passed points a, b, and c. They don't have to perfectly scan every phone, or perfectly know every MAC address. They're just trying to learn the average speed of the traffic moving on a particular stretch of road at a particular time.

          They can get equal information from a spoofed MAC.

          Now, what they probably aren't expecting is a concerted effort b

    • by vux984 ( 928602 )

      Well, there's a relatively recent 'distracted driving' law there that prohibts handheld electronics while driving amongst other things.

      So there are more than -plenty- of people to monitor driving around with a bluetooth handsfree solution of some sort.

  • by bjdevil66 ( 583941 ) on Wednesday November 28, 2012 @08:42PM (#42125041)

    Of course no government or private entity would ever start tracking speeds of drivers and start sending owners of the phones speeding violations if they're deemed to be speeding, right?

    • God damn it, that's not even remotely possible.

      • Cars have unique identifiers (VIN). When you register your car with the government (as you are required to do to drive it on public roads) you provide your name and the VIN to the government.

        The car manufacturer assigns the VIN to the car. For a factory installed Bluetooth system in the car, the car manufacturer also knows (or could get) the BT MAC address and store that in a database matching the VIN to the BT MAC. The government could require the car manufacturer to make this database of (VIN, BT MAC) pai

        • Who said the BT MAC addresses of the cars are unique?
        • by Pulzar ( 81031 )

          Doing this would be a bad idea. BT MAC can be spoofed so pranksters could make trouble. Speeders could turn off BT in their cars.

          However, I do think it is very technically feasible to do it.

          Wait, so you're saying the system is easily corruptible and bypassable, but it still makes it feasible? To use the common phrase around here, I don't think that word means what you think it means.

          • by Obfuscant ( 592200 ) on Wednesday November 28, 2012 @11:04PM (#42126149)

            Wait, so you're saying the system is easily corruptible and bypassable, but it still makes it feasible?

            Back in the 60s, they had these things called "payphones". Little slots you put money in, you got to call other people. There was info around specifying what kind of washer (and the mod to it) would substitute for a quarter. Easily corruptible. Some of the phones, all you had to do was short the microphone case to the phone and you got free calls. Easily corruptible. Very feasible.

            In the 70s, the uni library had a copy machine system that people could put a card into and charge copies to their accounts. A simple plastic card, with an internal layer that was opaque to IR -- except for the holes punched into it before being laminated between two IR transparent but visibly opaque covers. Easily corruptible. (All you had to do was punch holes in a standard playing card until the system accepted it as valid...) Very feasible.

            Every so often, the road department puts out traffic counting systems to determine how many cars use certain roads. Used to be a simple hose with a pressure sensor. Yeah, someone could jump up and down on the hose and create fictional cars. Easily corruptible system, but very feasible.

            Any system where the expectation of being gamed is low enough that the cost of being gamed is covered by the honest people is still easily corruptible but quite feasible for regular use. Most people aren't going to be spoofing their bluetooth MAC address while driving down the road, if they even know how to do it. That makes this easily corruptible system quite feasible for measuring average traffic speeds.

    • No, because you can't give me a speeding ticket for being a passenger in a car, taxi, bus, train, back of a police car...
    • Well, you really do not need bluetooth to track cars. All cars have license plates that you can read with a camera and some software. This is widely used on the highways around my city, for over 5 years now. Sometimes I am really surprised how out of touch Slashdot's self-proclaimed nerds are with technology: []
  • Of course, if you live in Calgary and you have to drive anywhere via Deerfoot, Crowchild or Genmore anywhere near rush-hour times you're painfully aware of how congested the traffic is, no need for realtime updates when there's 40 cars of stop and go in front of you.
    • When they ran the pilot last year (or was it two years ago) I found it useful and actually was fairly accurate. Deerfoot bottlenecks and congests at certain points every day and once you are past those it moves along OK if there aren't any accidents, blizzards, etc. If I see an estimated time that is way larger than the usual time including bottleneck congestion I'll probably try a different route. I was surprised and happy to see it up and running yesterday.
  • Surely that should be "blueteeth"!

  • If they only need the MAC addresses for the time that the device is traversing the system, then there's no reason to log the data for long term. TFA doesn't say how long they keep the data. Were the journalists too stupid to ask that obvious question, or did the government say "We'll get back to you"?

    • If they only need the MAC addresses for the time that the device is traversing the system, then there's no reason to log the data for long term.

      "If they only need information X for a short time, then there's no reason to log information X for the long term." Insert your own phrases for "information X" and see how it applies to government (or private corporation) systems. Try "web query" and then think about how many websites log that information for a very long time. (Mine keeps logs back to ... mid '90s, probably. Definitely more than five years.)

      How about "gun purchase background checks"? How many years are those kept?

      How about "GPS road-tax t

      • why would you imagine they'll throw out perfectly good data once they have it?

        I realize that asking people to read the article they're commenting on is a stretch, but they say "without tracking other information about the traveler to minimize the impact to the person’s privacy", hence the question about logging..

        • I realize that asking people to read the article they're commenting on is a stretch,

          I realize that taking the government's word at face value is a stretch, but I'm glad you do. You keep the other end of the bell curve bell shaped.

  • I have a page with links to other examples of, and discussion about, bluetooth traffic monitoring; see []
  • Could have saved them a bundle with my competing technology, a sign that says "5:30am to 8:30pm: congested"
  • ...but come on, does anyone here really believe that if you choose to enable your Bluetooth device that others are not free to interface with your device to the extent that they can uniquely identify it? If you don't want to be tracked, maybe you should think twice about turning on Bluetooth.

    • Bluetooth, Tire pressure monitors, Cell phones, Keyless entry fobs, seriously, are you going to just shut them all off while traveling. Bluetooth is just one of many ways to track the travel times of an individual vehicle. Add ANI to the list. A growing database can figure out of you took the alternate route, worked late, or detoured to the taven on the way home from the historical data collected.

      The question is is the data compiled or discarded daily? This was not mentioned. Dept of transportation may

    • Not just turning on Bluetooth, turning on discovery too. Although a lot of bluetooth car kits/head units default to on+discoverable.
  • by petman ( 619526 ) on Wednesday November 28, 2012 @10:22PM (#42125853)
    Personally I think this is an ingenious use of technology. You people are so paranoid about privacy. You seem to be able to find a sinister side to everything, don't you? Come on, get over it. Let's celebrate creativity instead of always raining on people's parade.
    • Did you realise you are reading Slashdot?

      Your interjections of common-sense based reasoning and mildly optimistic outlook are not wanted here.

      Paranoia exists here because *they* really are out to get us. The world really is only a finger width away from total annihilation and the zombie apocalypse is not only plausible, but inevitable and about to happen at any minute.

      As every single reader of Slashdot is an American, we all have our fully automatic firearms ready and loaded ( and concealed ) , waiting for

    • by antdude ( 79039 )

      Everyone, let's spy/stalk on Petman. [grin]

    • The fact that this comment has been modded insightful and not funny is a very real proof that the Slashdot readership is far removed from the hot grits days.

    • Personally I think this is an ingenious use of technology.

      I totally agree. In the end, however, my paranoia is your naivete. People in positions power tend to maximize that power (or profit) over time. It's simply "good business" or "strong governance". If they could turn at system like this into information to use against you (or to legally take money out of your pockets), they will.

      Here in Arizona there are technology company lobbyists working all the time to increase the surveillance on us, marketing

  • It seems that every comment so far has centered on the privacy implications of the collection of MAC addresses, I'm a little more concerned with where the collection of a few more bytes of data could go. I'm a few years out of the parking industry now, but the big new technology just few years ago was the use of OCR to collect license plate numbers in real time. I recall an industry presentation hawking a handheld device that could take a picture, and do the computation with little noticeable delay. It s
  • A bit off-topic, but have you heard they're going to be tracking cell-phone (and accessories) signals to monitor traffic patterns? It's amazing! Why doesn't Slashdot ever accept a story on the subject?

    You can read more here: [] [] [] [] [] [] []

  • The basic idea is that you use a set of Bluetooth receivers interspersed along a traffic corridor and attempt to track unique MAC addresses through the corridor and thus you can come up with an average, near real time, travel time through that corridor.

    Some of the more interesting parts of doing include a car full of people, each with a cell phone and a laptop and quite possibly the car's own Bluetooth system. So while it is good for averaging speed and validating other measurement methods, it is not very

  • "As for privacy concerns the city says it cannot connect the MAC address collected to the device owner."


  • by Animats ( 122034 ) on Thursday November 29, 2012 @02:48AM (#42127071) Homepage

    CALTRANS uses loop detectors in freeways and major roads to monitor congestion. They just count cars in each lane and measure how fast they're going. They've been doing that for over two decades. You can see the result at . LA used to have a dedicated cable channel with that data. No privacy-invading user-identifying technology needed. []

    The data is used in several ways. The most important one is that when the system detects high traffic density at slow speed at one sensor, and lower density at higher speed at the next one in the same direction, it means trouble, usually an accident. The traffic detectors report the lanes separately. If something is blocking a lane and traffic is going around it, that's detected too. Cell phone and Bluetooth monitoring won't give you that.

    CALTRANS has had cameras (which you can watch on line) [] on high poles over freeways for decades. Some have pan, tilt, and zoom capability, so when the automated system detects trouble, someone can use a camera to look at the problem area and dispatch whatever is needed.

    Another use of this data is to control the metering light system at on-ramps. Freeway throughput peaks at 35 MPH (at higher speeds, the cars have to space out more) and cars are deliberately delayed a few seconds at on-ramps when speeds drop below that level.

    Both of these functions require reasonably accurate data, but there's no need to identify cars individually. This all works quite well without it. Probably better. Counting all the cars on a second by second basis is more useful for detecting problems fast than some statistical measure of some of them.

    The data also goes out to web sites, apps, driving time predictors, etc. There's an free API [], integration with transit data, integration with CHP incident info, a developer group, etc.

    A truism of traffic management is that fast response to trouble on a freeway increases the capacity by about one lane, and it's a lot cheaper than adding a lane.

    So I'm not too impressed with some small-scale trial that snoops on Bluetooth headsets.

  • It's been done in the Netherlands on dozens of locations already. Also, "anonimized" cell tower information (GSM/3G) is being used by TomTom to do the exact same in several countries.
  • It's a perfectly cromulent word.
  • Some of the highways around Philadelphia now have a similar system, but I believe they may use the EZPass toll collection RFID tags to get travel times.
  • The system collects the publicly available data from Bluetooths to estimate

    Wouldn't that be Blueteeth?

  • The same system is being installed around Boston, MA and other localities. I love seeing the sign and knowing how long it is going to take me to reach a certain point. It takes a lot of stress out of being stuck in traffic. Less stressed drivers means traffic loosens up and moves more freely, instead of people bunching up on each other's cars and causing a traffic jam.

    Additionally, the data will be publicly available, so mapping applications on GPS devices and smart phones can show traffic congestion in rea

    • Similiar systems have been in used at airports for years, to measure waiting times at security checks etc. The ones that measure road congestion can be bought off the shelf, or can be rented (when a construction company works on a stretch of highway for instance). This is really old technology, and I wonder how it ever got up to Slashdot's front page.
  • How would they differentiate between people walking along the street with their phones in their pocket and BT-enabled cars driving along the same street, if all they're basing the collection on is the device MAC address?

  • The city of Minneapolis also estimates travel time and displays the information via over-road screens. I'm not sure how they calculate the trip time (I don't believe it's via bluetooth), but it's a waste of effort, time, and thus money

    Here's why it sucks: The display boards are infrequent - there's like 1 board along my 25 minute drive, and I drive via heavily traveled highways and freeway. Because they are so infrequent, I can only obtain trip length information for half of my trip.

    Here's what they sh

  • there was this case, when aol released search data together with a pseudonymous user-id. Many people got uncloaked, because first they searched for their own name or some other identifiying information, then for something like sex toys.

    So the bluetooth-data isn't anonymous, too. Now they have the MAC and your traffic pattern, and when you have your device with you when you're alone somewhere i.e. in a police office, they may collect your MAC and connect it to your full name. When they later get access to th

The world is coming to an end--save your buffers!