Garmin delivers HD traffic via DAB radio

Free-for-life HD traffic service without a subscription

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Proper HD traffic data for sat nav devices always used to require an internet connection. But now Garmin has announced a new HD traffic service that uses the DAB radio network.

In simple terms, it's similar to the RDS-TMC system. RDS-TMC, of course, stands for Radio Data System – Traffic Message Channel. It's been around for donkey's (that's a technical term) and essentially piggybacks on the RDS platform's ability to send out text data for identifying radio stations.

Bandwidth bottleneck

Problem is, RDS-TMC is preposterously low bandwidth, topping at a feeble 37 bits of data every one to three seconds. That's fine for listing the name of a radio station. But it's pretty hopeless for transmitting detailed traffic data to cover 250,000 miles' of public roads in the UK.

To date, the solution has been to use a cellular internet connection to download much more detailed data. But that means either depending on a third-party device, such as a smartphone, for a data connection or maintaining an extra data account with a mobile telecoms operator. Neither is ideal.

That's why Garmin has teamed up with traffic data specialist INRIX to deliver a new HD traffic service that leverages the DAB digital radio network.

Free for life

This means it's still a broadcast-based solution, rather than a system that allows for downloading specific data. But thanks to DAB's massively broader bandwidth, both the detail and refresh rate of traffic data is on another level compared with RDS-TMC.

And because it doesn't require an internet connection, there's no need for a subscription. You get it free for life with compatible Garmin devices. The first such model is expected to be the Garmin Dezl 760, due later this year.

It's exactly the sort of HD traffic service we've been waiting for, so keep your scanners peeled on TechRadar for a review as soon as it's released. Oh, and for the record the UK will be the first country to receive the service. Yippee.