Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


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This discussion has been archived.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:
  • 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?

  • by icebike ( 68054 ) * on Wednesday November 28, 2012 @09:12PM (#42125309)

    There is a significant density of Android phones. Just about everywhere.
    I just whistled up a map of Calgary, and turned on the Traffic layer [google.com]. I can see every traffic jam in the city in real time.

    If you can't see that, perhaps you need to learn how to actually use your phone.

  • 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. [511.org]

    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) [ca.gov] 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 [511.org], 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.

Syntactic sugar causes cancer of the semicolon. -- Epigrams in Programming, ACM SIGPLAN Sept. 1982