Live traffic services are destined to be one of the biggest advances in GPS systems. While GPS devices strive to provide the fastest route from point A to B, they generally do so by considering the most optimistic road conditions. “This route will be the fastest assuming there are no traffic delays.” Traffic reporting services aim to change that. But which traffic services are the best in North America, what type of data is available, and how well does it work?
Traffic Data Suppliers
The traffic data suppliers, like traffic.com and INRIX, collect data from road sensors, local departments of transportation, data collected from operators of large fleets of vehicles, and other manual sources such as traffic helicopters and listening to police scanners.
In order for your GPS to report traffic information about your route, you need to be driving on a road which is covered by the traffic data suppliers.
Traffic Delivery Services
In North America, there are (currently) three delivery methods. The first way is through a wireless data system like that offered by MSN Direct. They take the traffic data collected by traffic.com and send it over wireless airwaves to a receiver that is either built into your GPS or added as an external antenna.
A second method is via a “silent” transmission over FM radio. In addition to the music you might hear from a radio station, other “silent” signals can be sent over the frequency. A special FM antenna is either built into your GPS or connected as an antenna which listens for those special signals being broadcast over FM radio frequencies.
The final, and least common method is to utilize a data connection from a mobile phone. Your mobile phone connects to the Internet over the phone’s cellular connection, downloads the traffic information, and sends it via Bluetooth to your GPS. Your phone must be in an area covered by your phone’s data plan’s coverage area. This is the method used by the TomTom PLUS services.
Incident Data vs. Flow
There are generally two types of data that can be received about the road network. Incident data and traffic flow data. Incident data refers to information generally about a specific point/event on a road such as an accident or construction work. Flow data is the average speed vehicles are currently traveling on a particular section of road. Having both types of data is obviously better. For example if the road you are on has only incident coverage, and the weather is so bad that traffic is backing up, you might not get any traffic alerts because there might not be a particular accident that is causing the slower traffic.
Combining Data with Delivery
When considering a traffic service for your GPS, you will want to find out two pieces of information ahead of time. (1) Which companies offer traffic data for the roads I want information for. (2) Which companies offer the traffic delivery service in the areas I will be traveling.
So that leaves us with a few different scenarios which will impact if you will be successful in getting live traffic data into your GPS.
- A) You are in an area where the road network is covered, and you can get a signal. This is the situation you want to be in.
- B) You are in an area where the road network is covered, but you cannot receive the traffic signal. Live traffic would not work in that spot since it can’t download the data.
- C) You are in an area where the road network is not covered, but you can receive the traffic signal. In this situation your GPS would always report no traffic for that location.
- D) You are in an area where the road network is not covered, and you cannot receive the signal. Your GPS won’t be able to download any traffic data, but even if it could it wouldn’t have data from that area.
So where are these locations? Consult the following chart.
|MSN Direct||Clear Channel
Total Traffic Network
|Incident||coverage list||coverage list||coverage list|
|Flow||coverage list||coverage map||coverage map||Broadcast
|coverage map||coverage, station list||Check your phone carrier|
I would take many of the broadcast coverage maps (not the data coverage maps) with a few big grains of salt. I routinely cannot get a signal in many of the areas claimed by the coverage maps. Those maps seem to indicate “best case” scenarios.
Which service goes with which GPS?
Most GPS devices are using the Clear Channel Total Traffic Network solution, down the middle column of the chart. If you are looking to use the TomTom RDS-TMC solution, the NAVIGON traffic system, or any of the Garmin devices that use the FM based traffic, that is where you need to look. Yes, that means that devices from different brands do often use the exact same data from the same traffic service. The differences in those cases come down to presentation. (More on that with graphics further down.)
Some of the Garmin systems use, or can use, the MSN Direct service instead. That system also includes weather forecasts, movie listings, and current fuel prices in addition to the traffic services offered.
If you have a Garmin device and are trying to decide between going the MSN Direct route, or the FM route, first check the appropriate coverage maps. That might make your decision for you. Where I live for example the MSN Direct service doesn’t offer flow data, only incident data. The Clear Channel TTN service offers both flow data and incident data. I can also receive the Clear Channel signal in my area, so it is almost no contest for my area.
Otherwise consider the subscription costs, how much you might use the additional services like movie times from the MSN Direct service, and how often you might travel outside your usual coverage area. In the cases of an apparent “tie”, I’ve found the Clear Channel Total Traffic Network (FM, RDS-TMC) system to provide slightly better data in the areas I’ve tested both of them in.
What Equipment Do I Need?
Generally you will need to purchase a traffic receiver to receive the traffic signal. An increasing number of devices come with an internal traffic receiver built in, but as of this writing those are still rare. For Garmin devices connecting via the Clear Channel, FM solution you will probably need the GTM-20 unless it comes with your device. For the MSN Direct service you will want the Garmin GDB 50 MSN Direct Receiver. TomTom devices connected to the Clear Channel traffic service will want the TomTom RDS-TMC cable, and TomTom devices connected to the TomTom PLUS traffic service will need a compatible mobile phone with a compatible data plan.
What’s the Cost?
Okay, so you’ve found that you live in an area where traffic reporting data (preferably flow data) is available and you live in an area where you can receive the traffic signal. How much does it cost? The cost will vary from device to device and from service to service. But here are some general estimates.
For the FM (Clear Channel) traffic service — Typically if your GPS comes with a traffic receiver, it will also come with a trial subscription. Generally this is a couple of months. After that, you can expect to pay roughly $60/year.
If you purchase the traffic receiver separately from the GPS, it will also typically come with a trial subscription, but instead of a couple of months the initial subscription will generally be for 12 or 15 months. After that time you can also expect to pay about $60/year.
The MSN Direct service typically comes with a 12 month free subscription at the time of purchase. After that you can choose to pay $50 annually, or a one time (lifetime) subscription of $130.
If you go the TomTom PLUS route, and happen to be one of the lucky people with a compatible phone and compatible data plan, don’t forget to factor in the cost of your data plan if you don’t already have one. While the amount of data transfer depends on the refresh rate you set and the amount of time you drive, TomTom estimates that with one hour or usage per day at a five minute refresh rate you will probably use about 2.5 MB of data per month. However with many people already having an unlimited data plan for other uses, this option can make a lot of sense. The traffic subscription itself is about $60 annually.
Why Pay at All?
Well, that is what at least one GPS company has said in the USA. NAVIGON currently offers a lifetime traffic service based on the Clear Channel Total Traffic Network/INRIX solution. It is also true that there are many free traffic services in Europe. Part of the difference on that side of the Atlantic is that often the data collection and delivery is performed by governments rather than private companies and the data is offered as a public service. In North America most of the work is still being performed by private organizations who (rightfully so) expect to be paid for the work they are performing.
What does it look like on a Garmin?
Pictured here is an image of the Garmin display while there is a traffic delay on the route. Note the icon in the lower right showing a three minute delay. When there is no traffic delay, no information is shown on the display. The display doesn’t change if there is, or there is not, traffic information being received. You can however look down at the power adapter and determine from the colored lights on the adapter if traffic information is being received. However this isn’t quite as convenient as having it directly on the display.
So what if you want to see the details of what is causing that three minute delay? You click on the “:03″ icon and it will show you these details. Here we can see that one mile ahead of my current location there is a delay of about three minutes. I can choose to avoid the delay if I wanted to, however in this case routing around it would have taken longer than just accepting the delay.
The Garmin Traffic item in the Menu offers a birds eye view of the surrounding area and its traffic information. Here you can see some yellow road just under the exclamation mark icon indicating slower flowing traffic. You can also see other traffic incidents in the area, but none that will be part of my current route. Clicking on the ‘View by Road’ button will send you to the screen shown in the next image.
You can also select to view a list of the current surrounding traffic conditions by accessing the ‘Traffic’ item in the Garmin menu. Here you can see a list of traffic reports surrounding my current area. On the route I have selected, there are currently no traffic delays. But you can see there is an area of Route 1A, 28 miles to the East, Northeast of me that there is some really slow traffic. If I knew I might be going on that road on my return trip, that would be something to watch out for.
What does it look like on a TomTom?
This image shows a typical display of traffic information on a TomTom device. In the upper right corner there is a yellow circle. This means that the GPS currently is not receiving traffic information as I’ve traveled somewhere that the signal can’t be received. Along the right is a bar showing my current location at the bottom, and destination at the top. 3.6 miles ahead there is construction work. Further ahead on my route there is a right lane or exit closed. Neither of these incidents are estimated to slow me down, or a time would be displayed to the left of the incident icon. You can also see on the road view, that there is a traffic icon on the road, just a few feet ahead of my current position. The road also has little yellow arrows on the road indicating heavier traffic. (But in this case not enough to cause a delay on my route.
In this image you can see a green circle near the top left indicating I’m receiving traffic information live. You can also see that there are three delays on my route which are estimated to account for a whopping 23 minute delay. Each little red circle on the map indicates a particular incident in the area. The two arrow keys allow you to view the details of each incident along your route on a map, as indicated in the next image.
This image shows the details of an incident along the route. It tells us that 11.1 miles from my current location (or about 11 minutes ahead on the road) that there is bridge maintenance work. The location of the bridge is described, and it shows that the delay is over a 1.2 mile stretch of road and that this delay will put me twenty-three minutes behind schedule. Quite a backup! In reality, as I drove through I was only delayed by about three minutes. This brings up the point that the traffic data isn’t always right. In this case I almost wonder if it was supposed to be a “2-3″ minute delay rather than a “23″.
How well does it actually work?
For many people, traffic services haven’t quite reached “prime time”. Often complains surround data that is delivered too late to be actionable, jams that don’t get reported at all, or people who drive the same roads frequently enough to know what the traffic will be like without needing a traffic receiver.
Traffic isn’t all gloom and doom though. If you frequently drive to more urban areas, but not enough to know the local traffic patterns, it can be a big help. The GPS devices will reroute you around traffic if it can find a faster route based upon the estimated delay. Just being mentally prepared for the drive ahead can be a big help too. I think there is also a hidden safety component to having live traffic. On a recent drive an alert came up that there was slow traffic two miles ahead. While I couldn’t avoid the traffic from my current position (and there wasn’t likely a faster route available anyway) I had the advantage of knowing that there was going to be slow traffic ahead and I could prepare for it ahead of time by slowing down and being mentally prepared for what was coming up.
If you are someone who would rather not be in slow traffic altogether, even if a route around without the slow traffic will take you a longer amount of time, the service can be valuable for you too. Most of the devices will still give you an option to route around slower traffic even if that means adding a little bit of time to your route.