Where does google maps get it traffic travel time from?


Recommended Posts

I travel to/from work on a 1 lane each direction road every day.  But google maps is extremely accurate at telling me what the travel time is on that road.  This morning there happened to be an accident on the road that was causing a rather long back up.  Google maps said that travel time was 50 minutes due to very heavy traffic.  How does it know this?  This road is a not a well known road that isn't on any traffic reports.

Link to comment
Share on other sites

It does get some data from your phone too as well as other people's phones that are sitting in traffic before you.

 

But I think there's an official source as well.

Link to comment
Share on other sites

probably some kind of sensors on the ground that detect the speed of the cars

 

I know there are sensors in the ground for stop lights but this doesn't make sense.

Link to comment
Share on other sites

Most roads don't have sensors in the road and in general they are used for Traffic count (excepting the ones at stop lights which tell the traffic system how long to run a light). It's generally from positioning data that most people send to Google. TomTom has a user network that does the samething where people can report traffic or speed traps and such things.

Link to comment
Share on other sites

It does get some data from your phone too as well as other people's phones that are sitting in traffic before you.

 

But I think there's an official source as well.

 

What info could it be getting?  Does the gyro in the iphone still somehow figure out how fast I am going even though the phone isn't moving and then send it back to the gmaps servers?  I am asking seriously because I am amazed at how accurate it is and not at the fact that it is freaky weird.

Link to comment
Share on other sites

Most roads don't have sensors in the road and in general they are used for Traffic count (excepting the ones at stop lights which tell the traffic system how long to run a light). It's generally from positioning data that most people send to Google. TomTom has a user network that does the samething where people can report traffic or speed traps and such things.

 

Now that makes sense.  I forgot that tomtom has that program.

PRISM

 

haha...

Link to comment
Share on other sites

What info could it be getting?  Does the gyro in the iphone still somehow figure out how fast I am going even though the phone isn't moving and then send it back to the gmaps servers?  I am asking seriously because I am amazed at how accurate it is and not at the fact that it is freaky weird.

 

They could be simply tracking Android users anonymously using GPS, or by reporting MAC addresses for routers you pass while driving (which have already been geolocated using data harvested by users like you... WiFi+GPS). You anonymously send speed+location data periodically.

 

They have the perfect monitoring network deployed with all the sensors necessary.

 

http://googleblog.blogspot.in/2009/08/bright-side-of-sitting-in-traffic.html

Link to comment
Share on other sites

What info could it be getting?  Does the gyro in the iphone still somehow figure out how fast I am going even though the phone isn't moving and then send it back to the gmaps servers?  I am asking seriously because I am amazed at how accurate it is and not at the fact that it is freaky weird.

 

Uh, the phone IS moving, its in the car with you. It uses the same triangulation that any app that gathers your location uses. Mostly GPS and cell sites. Obviously if that info says lots of people are stopped on a 65mph freeway, theres a problem and Google can put a red line on their maps. Some of this info is also gathered by traffic cams (which most major highways have now) and an algorithm gives the speed of the traffic on the cam for Google and others to use.

Link to comment
Share on other sites

I would assume that Google also predicts future traffic conditions as well based on historical trends. For example, if you have a six hour commute and Google knows certain roads get backed up during rush hour, it could route you around those roads during those times.

Link to comment
Share on other sites

Google has a huge amount of map (and related) data. Really huge.

 

Also, almost every time an app requests a location in Android or one of the Google Apps in iOS the data gets sent back to Google (for location history and some other things). While navigating they can use the data they get to measure delays. Another technique is using cell towers. Operators track how long phones are within a certain cell range and how many of them are in one cell range at a given time. In Belgium this is one of the primary traffic estimate mechanisms and it works quite well too.

Link to comment
Share on other sites

This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.