How does google maps estimate travel time on urban roads?

Discussion in 'Off-Topic' started by Neyolight, Oct 4, 2012.

  1. Neyolight

    Thread Starter Member

    Dec 13, 2011
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    Hello

    I always wondered how does google maps estimate travel time from A to B on urban roads? Does it take into account the delays at traffic light intersections, roundabouts , left and right turn or delay caused by congestion?

    Lets say if I want to go from A to B and there are 4 traffic lights in between the two points - surely the highway travel time method of computing travel time (Distance/ Average Speed) wont be accurate in this case?

    Thanks
    Neyo
     
  2. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    If I were estimating travel time, I do not add the delays for traffic lights. I doubt any of the mapping services ... or your GPS device ... gurantee's your time of arrival will be what it states when the estimatiion is done.

    At least the GPS device can "update" the arrivial time based on your location at the moment ... which will account for your driving habits (speed) up to the moment.
     
  3. Neyolight

    Thread Starter Member

    Dec 13, 2011
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    When you reach a traffic light many things can happen:

    1) You hit Green and drive straight through - No delay

    2) You hit Red and wait the entire cycle length - Delay Observed

    3) You join a queue at green and experience some delay

    4) You join a queue at red and experience greater than observed in 2


    Shouldn't accurate travel time prediction take into consideration all the above factors? We can also move from traffic light to roundabouts where even if you dont have to give way to anyone, you still slow down to safely go around it.
     
  4. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    I've been in the queue four cars back and didn't make the green light. The first car's driver thought it was more important for her to finish her text message than go on green.

    My delay was for an additional cycle. Should we account for inconsiderate drivers as well? There are reason's it's called an estimated time. In rural area's ... do you account for the time you might be behind that farm implement moving down the road at a much slower speed than the speed limit?
     
  5. Neyolight

    Thread Starter Member

    Dec 13, 2011
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    This sounds like a one-off incident. Dint anyone horn at her? You must be on an approach with a short green time.
     
  6. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    It happens far too often to be an isolated incident.

    There is a "short" green light that turns yellow by the time you cross the six lanes at a different intersection. But that crossing is controlled electronically so the main lanes have green the vast majority of the time. I can tell you at that intersection when I notice it's red, I start slowing down at about 100 feet and the light changes by the time I get to a complete stop. Then it's off to the races to make it across before the light turns yellow. So, I really doubt there is an "average time" you can absolutely count on when figuring out the Arrival Time.

    Traffic control signals are no longer fixed lengths.

    All horning does is annoy people ... except the intended. They get upset you interrupted what they were doing.
     
  7. loosewire

    AAC Fanatic!

    Apr 25, 2008
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    Gps times you,if you stop the gps go into reroute,so if there an offical request for

    your time,you would be timed to your last stop.If you turn it off,your cell phone

    could pick up where you left off. I would not try to fool mother gps,big brother looked

    out for mom when it counts and you have pass cameras you have no clue where

    they are....they are tracking you too. You can't get out of Dodge,only a few understands

    what that means. I am getting the the strange under lines under my words,mrs.Dodge

    is watching me.....I better dress when I come to the computer any more.When I sent

    the information the underlines disappear. I was using google gps today.
     
    Last edited: Oct 5, 2012
  8. Sparky49

    Active Member

    Jul 16, 2011
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    Not supposed to use your hornn when stationary in the UK.
     
  9. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    The navigation software on my android phone even accounts for traffic..
    I had my garmin gps and android phone set to the same location once for kicks and noticed the android phone had the arrival time 30 minutes after the garmin..
    I thought thats strange.. BUT Then I hit the traffic jam and it was almost dead on with the arrival time.
     
  10. Markd77

    Senior Member

    Sep 7, 2009
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    I don't know if they do this, but they could use real time data from other people travelling on the route, or predict how long it will take based on traffic on the same weekday and time from historical data.
     
  11. loosewire

    AAC Fanatic!

    Apr 25, 2008
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    Like I say a number of sources monitor movement.
     
  12. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    so your phone is being used for "other" things ... like feeding information to others. I wonder if your charged for the data stream your continually sending them.

    On the bright side, you'll be able to show law enforcement everywhere you've been at any given date and time.
     
    Georacer likes this.
  13. loosewire

    AAC Fanatic!

    Apr 25, 2008
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    I take the high road,I have posted that many times.

    Like there a under cover paid by the Elbo Room for security.
     
  14. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    The difference is, loosie, he signed the user agreement with that GPS app ... giving them permission to "tap into" his location. A simple court order could get them to turn over his position.
     
  15. loosewire

    AAC Fanatic!

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    G.P.S. on Loosewire on thursday.

    a. Enviromenal project

    b. Working with Byrant

    c. Promoting Loosewies Image

    d. All of the above
     
  16. paulktreg

    Distinguished Member

    Jun 2, 2008
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    I doubt very much any GPS navigation software takes traffic lights into consideration, you lose time at some and gain at others if they take an average. Time from A to B taking into account speed limits and local traffic conditions (if that information is available to them and Google probably do?) is all it needs.
     
  17. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    Paul,

    Your right. That would be alot of computing resources tracking millions of phones, certainly something only the largest of organizations has access to.
     
  18. loosewire

    AAC Fanatic!

    Apr 25, 2008
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    I was riding in a auto that had G.P.S. and a Ipad with google mapping

    with voice,when the auto changed directions or anything different in

    the plan,it say rerouting computing where you were and how long. If

    you stop when you start again the voice replies. So I would say,the

    timing and place is a factor that they have worked out,how may be

    story of its own.
     
  19. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    You certainly can update TOA based on the distance between current location and final destination, but that would not explain the discrepancy noted ... GPS and Phone Maps ... of 30 minutes.
     
  20. t06afre

    AAC Fanatic!

    May 11, 2009
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    But if my spirit is lost. How will I find what is near

    Don't question I'm not alone Somehow I'll find my way home

    My sun shall rise in the east So shall my heart be at peace

    And if you're asking me when I'll say it starts at the end

    You know your will to be free
     
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