GpsPasSion Partners




- -

Pour vous guider sur la Route :
GPS Mobile (SEM)
GPS Intégré
Voter  -  Résultat des votes
Votes : 2834

Club GpsPasSion
Soutenez le site!

USA: (US$)
Guide Paypal

GpsPasSion Forums
Home | Profile | Register/Enregist. | Active Topics | Search/Recherche | FAQ
Save Password
Forgot your Password?

 All Forums
 Advanced Topics
 Traffic Information (TMC)
 * Traffic in US : How it's Done, Who is Doing it *
 New Topic  Reply/Répondre
 Printer Friendly
Next Page
Author Previous Topic Topic Next Topic
Page: of 3


400 Posts

Posted - 12 janv. 2011 :  19:56:43  Show Profile  Reply with Quote
GUIDE - Traffic in the USA
How its Done, Who is Doing it

Companies such as Inrix, Navteq, AirSage, TomTom, Google and TrafficCast are using more and more innovative ideas to bring us more and more accurate traffic data at lower and lower prices.

How we got there

Eye in the sky
The original method of traffic reporting was the 'eye in the sky' reporter who flew over cities in a helicopter.

After the eye in the sky the next stage of traffic reporting used sensors built into the roads probably like loop detectors they use at drive throughs so they know you've pulled up have been in use in maybe 40 metro areas. Some are public and some are owned by Nokia/Navteq/ Interesting story about how taxpayer money was funneled to for sensors and a lot of them are the property of - not available to third party providers. At any one time a third of these is not working correctly and they are expensive and difficult to replace or install.

GPS Probes
The next idea was to use the gps systems built into trucks, cabs, buses, delivery vehicles to calculate traffic flow. Those probably are capped at maybe 1 million vehicles. Some of them do not update and send info but 1-4 times per hour. At any one time some are out of service, loading, unloading, stopped waiting for a new fare etc etc and long haul trucker often drive at night to avoid traffic. This is the method that Inrix (a Microsoft spin off) chose to work around. Bill Gates had toyed with traffic early on so this was a pet project for him.

Another start up early on in the late 90's was ZipDash. They had an agreement with Nextel to track their phones through the built in GPS. Nextel phones have always come with a gps in them but it was rare in other phones early on. ZipDash was purchased by Google in 2004 :

In the early 2000's General Motors did a study on traffic and came to this conclusion re gps probes. For accurate highway flow data nationwide - 3 million probes are necessary while secondary roads need 5 million. So 8 million probes are necessary to get good flow data across the US.

Coverage ?
At this point in the mid 2000 time frame Inrix and Google covered just the major highways. Meanwhile covered just the main metro areas, with no interconnecting highways. Inrix had slowly and steadily increased their probe count till in 2008 they claimed about 800,000 probes. Google was very secretive about their probe count at that point.

Cell Phone - Triangulation
During the same time period small start ups such as AirSage, Intellitraffic, Applied Generics (in Europe) and TrafficCast started to make waves along with some others such as Delcan, Cellint etc. They were all developing traffic flow data using cell phone triangulation. They all used similar methods but each has a twist of its own. After quite a few studies it was found that above 30mph this method is not only accurate but cheap to implement. Under 30mph this data needs accompanying data from gps probes for verification.

Applied Generics though had a way to get higher accuracy out of the data based on a pretty straight forward idea. The idea is that when traffic slows considerably people in that jam use their phone to call and say they will be late or just to make a call to ease the wait. So their algorithm takes that into account. In 2006 TomTom buys Applied Generics and signs a deal with Vodafone in Europe to use their phones through Applied Generics system for traffic they would call HD Traffic.

Dash : In and Out
It was about this time that a startup, Dash in the US came out with a gps connected to the cell network. The idea was to use the gps as a probe complimented by another traffic providers data - Inrix. The product was innovative providing features not seen anywhere else still, but the routing was terrible and they never had the numbers for good traffic data. Dash is purchased by RIM and seemingly buried.

Cut to today and things have changed dramatically.
Google now combines AirSage cell phone triangulations with their own gps probes. AirSage monitors both Sprint and Verizon phones totaling 150 million phones while Google uses gps tracks from their latitude app (just made available for the iPhone), their Android phones which are now selling at a clip of 300,000 a day, and possibly still the Nextel probes - I am unsure of that. Google may have as many as 30 million gps probes in the US or as few as say 15-20 million. Still that makes them number 1 and as they tweak their own algorithms their data should get better and better. Google has reached the magic number for accuracy.

Inrix now claims north of 3 million probes and I believe they are being conservative. They had about a million when two things started to happen: they started free traffic apps for the iPhone which is popular and the service provided for Ford (and recently starting for Toyota) is bearing huge fruit in the form of probes. Ford just announced their Sync product has reached 3 million users. Its likely Inrix is north of 5 million right now. Inrix also has incident data they receive from local DOTs (Department of Transportation) and from Clear Channel (FM Radio) plus they add in variables for school buses, weather, events and red lights. They maximize what they have and they are closing in on the magic number.

TomTom HD Traffic is considered the best there is in Europe. They have 90 million Vodafone phones being tracked across Europe and a few million gps probes from their connected gps systems there. They estimate they will have 25 million gps probes in Europe by 2014. They have just announced HD Traffic in the US but its significantly different. Here is the best information on the web right now on whats coming from TomTom later this year coutesy of "GpsPasSion"'s CES report via TomTom's US head of US traffic. This info will not be found anywhere else on the web unless its copied from his post. I believe with the accuracy of IQ Routes TomTom feels they just need to see the exceptions with fewer probes and I believe they used the last two years to experiment using TrafficCast's probe info. Unique to TomTom for now is the use of OpenLR that allows them to place traffic information on potentially 6 million miles versus de 0.5 million miles afforded by TMC codes built into maps.

Other players in the industry are NIM which turnkeys their product to cell carriers such as Verizon's Navigator. NIM bought out Traffic Gauge for their back office traffic savvy and to turn their customers into probes. NIM/TCS uses the 14 million Navigator users as probes and feeds that back to the users. I believe they use Navteq/ as the provider and tweak with their own data. NIM has reached the magic number but its unclear at this point whether they are losing market share. NIM was bought by TCS which almost certainly will further monetize the probes and sell the raw data to other providers.

RIM at the beginning of the summer announced they would start using Blackberrys as probes and that customers would have to opt out meaning the uptake will be huge maybe 80% and Blackberry has about 20 million phones in the US so maybe 16 million probes. This is Dash back from the dead with some huge numbers to work with. RIM from what I can gather will make these available to other providers on a raw data basis.

TrafficCast this year will update their flow coverage to 880,000 miles about the same as Inrix. They are touting a method of tracking cars by bluetooth. The roadside sensors which are solar powered and linked via wireless radio watch for a bluetooth signal to come by within 250 feet So you are driving by and it picks up your phone traveling at 65mph or the EZ -Pass transponders people have for toll travel are also bluetooth in nature so those can be tracked. TrafficCast claims this method is 1/300th the cost of using cell triangulation or gps probes. The sensors are just bolted down near the road and thats it. The rest is wireless.

Finally the original mother of traffic providers in the US was bought out by Navteq in 2007 then Navteq was bought out by Nokia. So Nokia has run two tests of using Nokia and Blackberry phones as gps probes using 'trip lines' rather than a continuous tracking. Nokia rolls out 1.2 million gps capable phones per day however most of them are outside of the US. Only T-Mobile in the US subsidizes Nokia phones for sale and Nokia does not manufacture a CDMA phone although on occasion they come out with them however they are Pantechs and nothing like a Nokia. Nokia started letting users of Nokia phones free navigation to increase sales and get more probes. Nokia has increased their European coverage to a remarkable level - there are a boatload of Nokias there. Go here select traffic as an option on the left and look at the European coverage for London or Paris. They have said over and over again that the US will see a huge increase in coverage but nothing ever happens. Their new technology was developed in tandem with UC Berkley with a team headed by Professor Alex Bayen - a certified genious. Here he is on YouTube talking about the method he helped develop for Nokia. Traffic screens in an office flash some detail in the San Fran area - its coverage is very detailed :

Today's Methods
So the main methods of tracking traffic flow today are through gps
devices that can also send their location including fleets, and also
most cell phones now. Then its the use of cell phone triangulation and finally the newest method is through bluetooth.

There probably needs to be some consolidation or sharing of probe data among the big players so that the gps probe numbers can get really big. Based on the rapid change this part of the gps business has gone through I predict in a year or two high quality traffic data will be the norm.

Transmitting the Data to the GPS Systems on the Road
The last bit of traffic info is how you get it on your gps and how the traffic information distribution system affects the quality of the data.

The original method which is still in use via FM Radio is TMC-RDS: This wikipedia profile tells you the basics. Problems with this method are the data transfer speed which is extremely low 40 bits data transfers, low speeds and since its one way via an analog signal they must repeat the same info over and over for errors which are caused by low signal levels, multipath, tall buildings etc. TMC is limited to class 1 roads the highways only. Due to speed limitations and the multiple transfers to account for errors the data you get is both inaccurate and untimely.

A much better one way system is available but there has been only one 3rd rate gps company to start using it - traffic data over HD Radio. One time transmission with much much faster speeds and bandwidth. These if it ever replaces TMC-RDS can send a great deal of data meaning secondary road coverage may be available this way soon. Coverage though is an issue because HD Radio just hasn't been a booming product. Its the chicken or the egg conundrum. Why build an HD Radio infrastructure if its not selling versus why buy an HD Radio product when there aren't a lot of stations using it.

Then there is the connected gps pioneered by Dash and taken up by TomTom and Garmin. When its working right traffic is the same as you'd get online and its robust meaning secondary road coverage is not an issue. This is where the future lays.

Websites to view Traffic Information
- Google Maps :
- TomTom :
- :

Questions, comments?

Edited by - offthegrid on 16 janv. 2011 17:56:19



1 Posts

Posted - 14 janv. 2011 :  04:24:01  Show Profile  Reply with Quote
Thank you for such a detailed summary of what's happening in the industry. I'm very impressed by your ability to see the big picture and back it up with details.

What are your thoughts arounnd the economics of traffic data? Are the vendors making money? I've long been curious about the business models and pricing for these data. Would love to hear what you think.

Thanks again for such a brilliant overview of the traffic business. Very impressive!
Go to Top of Page


94688 Posts

Posted - 14 janv. 2011 :  04:59:09  Show Profile  Visit gpspassion's Homepage  Reply with Quote
Indeed, this is great, this is the first overview I'm aware of that gives such a full encompassing view of the methods and issues. I did some formatting, fixed a couple of typos (Applied Generics was bought in 2006, link added) and added some links.

I also added a section at the end, websites to view traffic, starting with Google and TomTom, we're missing a couple that you'd linked in previous posts.

I'll turn this into an article on the portal next week to get it as much exposure as possible and I modified today's news item to link to it ;-)

Discounts and Assistance/Réductions et Assistance (Club GpsPasSion) / Où commencer?
Go to Top of Page


1 Posts

Posted - 14 janv. 2011 :  12:04:30  Show Profile  Reply with Quote
Very nicely done! Question: what is the source of the traffic data on Bing's maps?

Originally posted by gpspassion

Indeed, this is great, this is the first overview I'm aware of that gives such a full encompassing view of the methods and issues. I did some formatting, fixed a couple of typos (Applied Generics was bought in 2006, link added) and added some links.

I also added a section at the end, websites to view traffic, starting with Google and TomTom, we're missing a couple that you'd linked in previous posts.

I'll turn this into an article on the portal next week to get it as much exposure as possible and I modified today's news item to link to it ;-)

Go to Top of Page


400 Posts

Posted - 14 janv. 2011 :  16:21:14  Show Profile  Reply with Quote
Thanks GP for the improvements - it looks great now.

Bing uses Navteq traffic.

Some other sites that have traffic on them and who they use or comments on some sites. which uses Inrix which also uses Inrix - but you'll see a difference between the two on the same roads from time to time.

Notably and also using the same data will show different results. uses TrafficCast but will change soon through an agreement with Nokia to use Ovi maps which shows no traffic through their online maps at this point.

Sigalerts now covers all major metro areas in the US. They have an agreement with AirSage and they've developed a fairly unique alert system but its for a fee. The maps are free though. Westwood One who now owns Sigalerts provides incident data. Intellitraffic is now Intellione and they have great coverage in metro areas in Canada using Rogers Wireless phones through their proprietary cell phone triangulation.
Go to Top of Page


400 Posts

Posted - 15 janv. 2011 :  01:02:52  Show Profile  Reply with Quote
I have some images from what are marked as proprietary documents I have come across on the web.

This is pic of Inrix's national coverage - its fairly comprehensive. Look at the Canadian data there - impressive also. I doubt any of the free traffic services online have their best traffic data. This is most likely reserved for paying customers.

This is their coverage in Phoenix. You can see every street is covered. Not only is every street covered but the color coding is correct. They say Green represents 45mph and above. So when looking at these traffic maps why do some small roads with 25mph top speeds show green? They shouldn't. This is again imo another difference between free and paid. Notice that all the secondary roads are yellow and red here.

This is a map of TrafficCasts next generation Dynaflow 3 which should be released soon. The red areas are existing coverage and the blue is the extended. The new coverage will also increase coverage within the red areas.

Finally from Navteq this blurb shows that at some point Navteq expects some huge increase in probes (the Nokias and possibly Blackberrys)plus it appears a major carriers cell triangulation data.
One of the things I believe holding up Navteq is they have to map the US with the virtual trip lines they are using in Europe and the US is just a larger project. They are done or close to done in Europe and the US is on deck so to speak.

Edited by - offthegrid on 15 janv. 2011 16:57:23
Go to Top of Page


400 Posts

Posted - 15 janv. 2011 :  01:08:29  Show Profile  Reply with Quote
GP if you'd like to put the 2 posts I added into the article feel free.
Go to Top of Page


1 Posts

Posted - 23 janv. 2011 :  00:08:26  Show Profile  Reply with Quote
Excellent coverage. Is OnStar data used by anyone?
Go to Top of Page


400 Posts

Posted - 24 janv. 2011 :  04:33:24  Show Profile  Reply with Quote
Its very likely that every source including OnStar is being used by someone. The real problem in the US is that there are too many cooks and not enough stock to start a good soup.

There needs to be some consolidation. I really thought AirSage would be bought up on the cheap but they appear to be doing well on their own and they offer data that no one else can generate in the US. Its unlikely that Navteq will buy anyone they are on their own path.

The lingering question is when will TomTom or even Garmin pony up here and buy one.
Go to Top of Page


400 Posts

Posted - 08 févr. 2011 :  12:07:07  Show Profile  Reply with Quote
And so the clock moves back even as it moves forward.

This concept, TrafficTalk, makes everyone a potential 'eye in the sky' able to report traffic tie ups, accidents and such to other users in a particular area.

You just need to dial the number and enter the code for an area. Its available in the top twenty metro areas right now with more coming.

Each area is broken up into smaller areas. When the conference calls get congested the plan is to have a host for the call who will control things and keep them manageable.

Here is the break down for the Boston area just to show an example. When you move from area to area you simply dial back in and enter a different code.

You can report that traffic is slipping by in the outside lanes or just where an accident is so people can get off and back on the road in the right spot. These are details that are not available via probes and so the potential is huge. It just needs users to call in during rush hours.
Go to Top of Page


190 Posts

Posted - 19 févr. 2011 :  18:18:35  Show Profile  Reply with Quote
A couple of remarks:

TomTom HD traffic was mentioned. I'm currently using Live Services on an XL 340S, which, at $10 per month, gives the closest thing TomTom offers in the U.S.A. to HD traffic. In fact, the term "HD" is even displayed on the traffic tab, even if the TomTom world map does not show an HD icon for any U.S. cities. (Although not related to the topic of this thread, the subscription fee also gives access to other services, including a hybrid Google search feature - not nearly as powerful as Google internet searching, fuel prices and weather.)

But what of TomTom's free lifetime traffic? This is supplied by Total Traffic Network, so how do they fit into the picture?

Also, when talking about Android phones selling at 300,000 per day, I am assuming that most of those are NOT Google phones (since the Nexus was initially a bit of a flop, from what I understand, although a new model Nexus S has recently been released).

Some further considerations about traffic enabled devices. In my use of TomTom Live Services traffic, I have found two things very useful:

Firstly, the fact that information is not limited to major highways. Google traffic maps also provide information about other streets, but none of the free lifetime traffic receivers seem to do so (including TomTom or Garmin).

Secondly, regardless of how accurate the traffic information available is, IQ Routes seems (an assumption on my part) to enable TomTom units to make excellent choices of alternate routes. This often means that, when avoiding traffic, new arrival times of the alternate route are very accurate: usually to within five minutes or less, frequently to within three minutes or less. One does not end up leaving a crowded freeway, travelling at 15 mph, for crowded side streets travelling at similar speeds, or worse, but with traffic lights and impossible left turns (against oncoming traffic). This also means that if a traffic situation is encountered that the service may not be aware of, it is quite feasible to "manually" force an effective alternative route calculation, simply by requiring an avoidance of the next three miles of the current route, for example.

TomTom XL 340S LIVE, GO LIVE 2535M, XL 340TM (RDS-TMC) in LA traffic
Garmin StreetPilot 2720 (worthy, but retired)
Go to Top of Page


648 Posts

Posted - 25 févr. 2011 :  17:43:53  Show Profile  Reply with Quote
One of the most complete explanations of traffic probes, issues and solutions I've see has been posted by ArsTechnica Here

Garmin 1695 / 760 / 255 / Navigon for Android / Navigon 8100T / Garmin Dakota 10 / Geomate
Go to Top of Page


400 Posts

Posted - 28 févr. 2011 :  02:28:26  Show Profile  Reply with Quote
@Kex - Every Android is loaded with Google software including the free Nav which seems quite popular. So all Androids are Google phones. Google created Android.

Total Traffic is just Clear Channel's accident alerts along with Inrix flow data on major highways. It uses TMC which is neither timely nor accurate since it does not cover secondary roads it really can't make a routing decision on what is faster.

The current TomTom traffic in the US is nothing at all like the service in Europe. They use real time traffic from TrafficCast which covers much less roads than either Google or Inrix's more robust product which is in use by some smartphone nav apps and by Ford's with Sync.

I had a 740 till recently and I never saw an HD tab showing anywhere unless that's a new incarnation. It also does not show HD on TomTom routes online.

TomTom will be saying the US has HD Traffic when the new Live models come out here but it still will not be what they have in Europe. More like HD Traffic lite.
Go to Top of Page


190 Posts

Posted - 28 févr. 2011 :  03:48:14  Show Profile  Reply with Quote
Thanks for the clarifications. I'll be able to compare Live Services traffic to the regular Total Traffic Network traffic soon enough, since I have both now (two XL 340 units that is: one with Live Services, one without).

The HD icon started appearing on our XL 340s with Live Service after one of the software updates last year. When you click on the appropriate area of the screen to show the details of a current route, you get a summary on the right of the screen with details of any delays (and other Live Services information, which includes fuel prices on the route and red light cameras on the route). There are two "tabs" of information that can be selected in that area. Here are the images I promised before editing this:

1) Route Summary, showing the two tabs, including the "Live" Tab:

2) When you click on that "Live" tab, here is what you get:

3) When you click on the traffic area of those three items, here is what you get, with the "HD" logo included:

4) You can also access that area more quickly by simply clicking with your finger on the traffic "line" down the right side of the screen, and that will take you to this menu, where you need only select the "Show traffic on route" icon to get to (3) shown above:

5) Finally, just out of curiosity, for those that don't know it, here is the pop-up screen offering an alternative, faster, route. You can choose not to be give the option and just let it recalculate the route automatically, but I prefer to know what the unit is doing and that it is working "properly":

Like you said, though: that doesn't really make it HD traffic.


Some units are sold with Live Services and lifetime traffic. Obviously, if you buy one of these and don't maintain a Live Services subscription, all you get is TTN traffic information, but I'm wondering what happens if you do maintain a subscription to Live Services: is the TrafficCast information all that is used, and TTN ignored, or does the unit attempt to amalgamate both sources of information? Theoretically, the charger cable for these must have the TMC receiver, whether it's using it or not, so, it's "always on", right?

TomTom XL 340S LIVE, GO LIVE 2535M, XL 340TM (RDS-TMC) in LA traffic
Garmin StreetPilot 2720 (worthy, but retired)

Edited by - Kex on 02 mars 2011 00:24:04
Go to Top of Page


400 Posts

Posted - 13 mars 2011 :  21:36:43  Show Profile  Reply with Quote
Yes if you have the free TMC lifetime traffic its TTN and Live is TrafficCast. No mixing is done.

The 2535 will be the HD Traffic.

Go to Top of Page


400 Posts

Posted - 10 mai 2011 :  23:49:51  Show Profile  Reply with Quote
AirSage, in a Wall Street Journal article today, said that as of now they are not yet using any data from Verizon.

Given how long ago the announcement was that's a bit odd.

I can only imagine that they have placed a premium on the added probes and no one has stepped up.
Go to Top of Page
Page: of 3 Previous Topic Topic Next Topic  
Next Page
 New Topic  Reply/Répondre
 Printer Friendly
Jump To:
GpsPasSion Forums © 2002-2017_GpsPasSion/Manzanite Go To Top Of Page
This page was generated in 0,62 seconds. Powered By: Snitz Forums 2000 Version 3.4.05