enjoyingsilence
Been here awhile...
I read a thread posted recently regarding some issues with the XM Nav Traffic service available on Genesis (Genesi?) equipped with the Technology Package, and felt compelled to offer some technical information on the service and technology utilised in the following:
Most of the information available on XM NavTraffic can be read here.
To save readers, members, and lurkers, some confusion, time. There is a 5-15 minute (if not more) delay from the time an agency (whom I'll discuss) reports a traffic incident (accident, traffic delay, etc) to XM's traffic center, to the time it makes it to your car.
While this is the "general" description of how the service is advertised, your car only requests updates somewhere in the realm of "every 5 to 15 minutes", giving XM an average of 30 minute delivery (up to).
The agencies who report these include, but are not limited to: your local state's dept. of transportation, 911 dispatch centers, FEMA, fire departments, and others.
The reason XM NavTraffic customers may not see certain accidents is due to your local agencies not reporting them to the proper facilities. XM uses a technology called TMC.
TMC is an acronym for Traffic Message Channel, and, in the United States is also used by ClearChannel to broadcast over traditional FM channels using the FM-RDS spectrum.
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Traditional Traffic Information is, as stated above, the TMC FM-RDS services, provided by ClearChannel ( and Tele Atlas in some areas ), which is free. As there is no middle man involved (e.g. Police Agency reports to XM Traffic Center > to your car (which pings XM every 5-15 minutes for an update), this service can be quite reliable. Your local radio stations already do a traffic report OTA (over the air), and as such, the necessary information is sent immediately to cars which support this feature.
A number of cars use TMC (or what I refer to as traditional traffic information), such as BMW/MINI, and likely a number of others, and often the necessary equipment, much like the Genesis, is packaged with a Navigation system. However, a subscription is not required.
Another benefit to traditional traffic information over the FM-RDS system, is a MUCH larger coverage area. Currently XM has just over 50 markets they cover; and as we know, ClearChannel is one of the largest media outlets in America, with over 900 radio stations.
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While FM radio range may seem "out of date" or "blind" compared to the Nationwide coverage of XM radio, bear in mind, XM NavTraffic works with your GPS system utilizing your location, with a range (usually of 150-200 miles) showing you traffic information within that area. Most of this information is useless.
TMC FM-RDS (or traditional traffic info)
is being broadcasted from the radio station in YOUR area, giving you more up to date and local traffic information. Cars equipped with this technology will provide option to choose from multiple radio stations (if available) broadcasting traffic information...
For example, in the Jacksonville, FL area 107.3 FM broadcasts our traffic information. However, if there was another, I would've been able to select that radio station.
The ability to select an alternative radio station (or traffic information source) is beneficial if you travel, OR, if you are on the fringe of 2 metro areas.
For example, (while I have not proven this, it's a worthwhile example). Dallas & Fort Worth. Being broadcasted over FM Radio.. if you live in a suburb of Dallas, and want traffic information for Dallas (assuming you work there), you would select the radio station corresponding to Dallas. Not Fort Worth.
It keeps you from having traffic information displayed that is not useful to you. And also prioritizes incidents & traffic information based on the radio station broadcasting closest to you.
(I hope that wasn't too confusing).
--
In summary, I hope this clarifies a lot of confusion, tension, and inquiry regarding the two primary (as of this writing) types of in car traffic information.
(caveat: these technologies are subject to change at a moments notice, and some terms reflect my opinions and have not been validated by the companies I have mentioned. additionally, Sirius also offers traffic services, as well as a menagerie of 3rd party navigation companies)
- XM NavTraffic
- Traditional Traffic Information
Most of the information available on XM NavTraffic can be read here.
To save readers, members, and lurkers, some confusion, time. There is a 5-15 minute (if not more) delay from the time an agency (whom I'll discuss) reports a traffic incident (accident, traffic delay, etc) to XM's traffic center, to the time it makes it to your car.
While this is the "general" description of how the service is advertised, your car only requests updates somewhere in the realm of "every 5 to 15 minutes", giving XM an average of 30 minute delivery (up to).
The agencies who report these include, but are not limited to: your local state's dept. of transportation, 911 dispatch centers, FEMA, fire departments, and others.
The reason XM NavTraffic customers may not see certain accidents is due to your local agencies not reporting them to the proper facilities. XM uses a technology called TMC.
TMC is an acronym for Traffic Message Channel, and, in the United States is also used by ClearChannel to broadcast over traditional FM channels using the FM-RDS spectrum.
--
Traditional Traffic Information is, as stated above, the TMC FM-RDS services, provided by ClearChannel ( and Tele Atlas in some areas ), which is free. As there is no middle man involved (e.g. Police Agency reports to XM Traffic Center > to your car (which pings XM every 5-15 minutes for an update), this service can be quite reliable. Your local radio stations already do a traffic report OTA (over the air), and as such, the necessary information is sent immediately to cars which support this feature.
A number of cars use TMC (or what I refer to as traditional traffic information), such as BMW/MINI, and likely a number of others, and often the necessary equipment, much like the Genesis, is packaged with a Navigation system. However, a subscription is not required.
Another benefit to traditional traffic information over the FM-RDS system, is a MUCH larger coverage area. Currently XM has just over 50 markets they cover; and as we know, ClearChannel is one of the largest media outlets in America, with over 900 radio stations.
--
While FM radio range may seem "out of date" or "blind" compared to the Nationwide coverage of XM radio, bear in mind, XM NavTraffic works with your GPS system utilizing your location, with a range (usually of 150-200 miles) showing you traffic information within that area. Most of this information is useless.
TMC FM-RDS (or traditional traffic info)
is being broadcasted from the radio station in YOUR area, giving you more up to date and local traffic information. Cars equipped with this technology will provide option to choose from multiple radio stations (if available) broadcasting traffic information... For example, in the Jacksonville, FL area 107.3 FM broadcasts our traffic information. However, if there was another, I would've been able to select that radio station.
The ability to select an alternative radio station (or traffic information source) is beneficial if you travel, OR, if you are on the fringe of 2 metro areas.
For example, (while I have not proven this, it's a worthwhile example). Dallas & Fort Worth. Being broadcasted over FM Radio.. if you live in a suburb of Dallas, and want traffic information for Dallas (assuming you work there), you would select the radio station corresponding to Dallas. Not Fort Worth.
It keeps you from having traffic information displayed that is not useful to you. And also prioritizes incidents & traffic information based on the radio station broadcasting closest to you.
(I hope that wasn't too confusing).
--
In summary, I hope this clarifies a lot of confusion, tension, and inquiry regarding the two primary (as of this writing) types of in car traffic information.
(caveat: these technologies are subject to change at a moments notice, and some terms reflect my opinions and have not been validated by the companies I have mentioned. additionally, Sirius also offers traffic services, as well as a menagerie of 3rd party navigation companies)
