How Accurate Is Garmin Traffic?by Aaron Charles
Garmin Traffic service is actually split into three different services: HD Digital Traffic, Live Traffic and Garmin Traffic. The accuracy of a Garmin Traffic service depends on which of these three is used. In general, though, Garmin Traffic accuracy hinges on two critical factors – the frequency and diversity of traffic data received by Garmin GPS devices.
Garmin Traffic Differentiation
The Garmin HD Digital Traffic service is available with select Garmin Nuvi models in the Prestige series, or with a GTM 60 Digital Traffic receiver and a compatible Garmin device. This service uses high-definition digital signals to transmit traffic data. The Garmin Traffic service (formerly called 3D Traffic) is available with many compatible GPS devices. And the Live Traffic (formerly 3D Live Traffic) service can be obtained with nuLink and LIVE devices, as well as with Garmin's Live Traffic Smartphone Link app for Android and the iPhone. See Resources section for listing of devices and their compatibility.
Frequency of Data
Since the HD Digital Traffic service is updated most frequently – up to every 30 seconds – it is the most accurate of Garmin's traffic services in terms of having the most updated information. The Garmin Traffic service, in comparison, is updated about every five minutes, and the Live Traffic service updates about every two minutes. Therefore, the HD Digital Traffic service is likely to be the most helpful when there are sudden traffic changes or accidents that slow traffic.
Diversity of Data
Garmin representatives have released specific information mostly about the HD Digital Traffic service, which pulls traffic information from 7,000 data points every five minutes – much more than analog devices that receive only around 300 data messages in the same amount of time. The sources providing this data include traffic sensors, construction alerts, incident reports, tolltags and highway probes. Every month, billions of traffic messages are sent to Garmin devices via the HD Digital Traffic service, helping paint a more accurate picture of traffic conditions. Furthermore, these HD Digital Traffic messages are more detailed than those available via the Garmin Traffic service. For example, instead of a "slow traffic ahead" message, a HD Digital Traffic message might say "stalled car in left lane."
Comparison with Other Services
Consumer and professional reviews show that Garmin's biggest competitor in terms of traffic service is TomTom. A 2012 PC Magazine review said that while Garmin's HD Digital Traffic service is accurate, TomTom's HD Traffic service has a leg up on Garmin's, citing a more user-friendly display detailing upcoming traffic conditions. Another 2012 PC Magazine review bluntly stated that TomTom's HD service is more accurate than Garmin's, according to "anecdotal testing." However, a 2013 Garmin review by GPS Magazine reported that Garmin HD Digital Traffic updates "should be more accurate" and give "better coverage than previous ... traffic receivers."