Traffic Alert Range

... in the EU I often get alerts about issues hundreds of miles away if they affect my route, no idea about the US though.

Using the Garmin SmartLink, I can get alerts up to 50-60 miles away. Generally because it's going to reroute you if there are big issues. SmartLink won't notify you if you aren't routing. It will just show red or yellow markings on the roads around you visible on the map.

The built in one is only going to show an alert at a much smaller difference, since the Traffic Coverage is pretty limited outside of the cities it's available in. So, it would depend on how large the coverage area is as to how easy you get an alert.

SmartLink, IMHO, works much, much better than the built in Traffic receiver.

I use the built in receiver. Never had any issues with it.

Guess the US is different

Wishing everyone a Happy Thanksgiving.

Coverage in the US is concentrated mostly around populous urban areas. Huge amounts of non-urban, slightly populated areas aren't covered. You can look at US coverage here, https://coverage.here.com/rds-coverage.html, but look quick, or reload the page as after a few seconds of viewing, the map reverts to a searchable map not showing coverage until you select a city.

All of Great Britain could fit in some of the uncovered sections, out west. (No, I'm not bragging. )

I lived there for a couple of years so I know how big and empty some parts of the US are

While going to the "Preakness" horse race in Baltimore MD one year, my 660 was alerting to accidents on the DC Beltway. I was in Ashland, VA (near Richmond). The wrecks were about 80 miles away.

Of course the 660 wanted me to re-route immediately (and not re-route when closer to the wrecks). That would have cost me a lot of extra time. I turned off the Traffic Avoidances and all was well. Then I just got the "Would you like to re-route?" messages every now and then, instead of constantly telling me to get off I-95 at the next exit and take U.S. 1 North.

By the time I got near DC, the wrecks had been cleared.

Metricman, that's been my experience, also, with long range alerts. Most will have cleared by the time you get there.

Just had a Smartlink alert for a <5 minute delay 65 miles away on our annual trip from BC to Arizona.

Canada has a greater land mass than the US, but we have only 10% of the population.

We have traffic coverage only near the major cities.

Both of them?

Just kidding, eh?

I used to work in an office building where Navteq was also located. They had several Ford SUVs in the parking lot with roof mounted equipment and laptop computers for the driver to use. These vehicles were presumably used for mapping.

On one occasion I needed to visit their office, where they monitored several government sources for traffic data, accidents, etc. using scanners. They also had a wall of monitors that were connected to the highway department's remote cameras to observe traffic. They have someone in the office who would send out the traffic alerts to their customers, including Garmin GPS receivers with the traffic alert feature.

IMHO - because I don't know for sure...
FM transmitted alerts are local because of the range of the FM transmitter.
Satellite transmissions cover a lot of area so the range would be limited to the GPS display and your route. Obviously, it doesn't make sense to show alerts for places you are not going to travel. You would need a rather large screen to cover it.
The GPS is probably receiving alerts for Montana when you are in Florida but does nothing with them because it knows where you are even if you don't.

Thanks for the info. I'll have to check more closely, but just starting with this gps I haven't had too many alerts. Or maybe I've been lucky in when I drive.

Ok, I decided to violate all protocols, and look at my 2699's manual. The first thing they say is to look at www.garmin.com/traffic for the type of coverage. phranc's post is spot on, he gave the website for HERE, the traffic provider. Hyperlinks on the Garmin page will take you to HERE for both Garmin Traffic and HD Digital Traffic.

Here is what HERE says about their data.

"We use information collected from a variety of devices across the globe including vehicle sensor data, smartphones, PNDs, road sensors and connected cars. Our traffic experts also monitor incidents such as accidents and construction as they happen, 24 hours a day, seven days a week."

And here is what HERE says about how they send it out.

"RDS and HD Coverage maps represent predicted RF signal density at a given location and are not intended to predict reception performance. Interference caused by geographic environment, receiver antenna type, nearby market frequencies, or other factors may affect reception performance. Maps are based on radio station data filed with the FCC, using the Longley-Rice Irregular Terrain Model (ITM)."

Now I have a good idea of where the Traffic data comes from and how it gets to my gps. The HERE map also shows coverage.

Have a good T-day if in the US, if outside the US have a chuckle because it is a traditional day to over-eat for us.

Good question. I need to check that out myself

All the distanced alerts I've received using Smartphone Link have been up to one hour's driving time. I've never seen an alert that was more than one hour ahead on my route.

The range sometimes seems directly tied to how often it successfully receives an update, and where it comes from after setting up a route. If it gets it early enough, it can warn you of traffic tie-ups along your route that are ninety minutes or more from your current location. (not particularly useful) If you're in a poor-reception area, and the updates are intermittant, you can drive right into the massive tie up with no warning at all.

One of the worst things about the free-traffic subscription is a result of a change (bug) they introduced in the early life of my Nuvi (at or around the third firmware release) where the traffic Icon would remain green, even if the receiver hadn't received an update for hours. Prior to the introduction of this "feature" (b*g), the icon color would turn from Green to Gray, giving a clear indication that no signal was available and the traffic feature was out of date. At some point they made it even worse: The traffic Icon turns green upon connecting up the power-cable/antenna: even if it hasn't been updated yet. This is confirmed by accessing one of the hidden traffic screens which show no channels received. What makes it worse is this information -is- shown/available on one of the other traffic screens ("traffic en route"?) where it not only shows the current signal strength, (bars) but also how old the report is (minutes), as well as a message "not recieving signal". So there is some very useful traffic signal and report information, just not where you can easily see it.

I live in Albuquerque, which is a place for which Garmin does not provide traffic service for either the scheme used by my 3790, nor that used by my newer 3597.

I generally take my current GPSr to the San Francisco Bay area a couple of times a year, and sometimes find the traffic information useful there.

An annoyance with the 3790 was that sometimes when I came home the icon indicating current traffic information would stay on for as much as a day after I came home.

Yet more annoyingly, the 3597 alerts seem to be downloaded with a "good until" tag, and it persists in altering the display in a way indicating traffic information usage until the last of those ages out (I think I see the text "no traffic on route", for example). On my last trip this took weeks.

If there is a file I could delete after I get home that would make this go away, I'd be pleased to learn it.