Garmin GPS - Accuracy of the traffic reporting on the Garmin nuvi is ... ?

Author

Accuracy of the traffic reporting on the Garmin nuvi is ... ?

_Pnina Gersten_

2007-08-23, 7:33 am

I was just wondering how people felt the accuracy (hence usefulness) of the
traffic reporting is on the Garmin nuvi GPS.

I bought a nuvi a few weeks ago and drove about a thousand miles so far and
have found the traffic reporting to be, well, just so so.

Sometimes it's nice that it says "45 minute delay" because I then know
there is really "center lane blocked" or "accident" or "construction", etc.

But, the five and ten and fifteen minute delays seem to vaporize by the
time I get to them.

What I've found myself doing is not trusting the traffic and crossing my
fingers by not detouring when I could, and sometimes running into the
bottleneck (although it never seems to be as bad as they say it is) and
THEN doing a detour around if I can.

Basically, I'd roughly give the traffic accuracy a score of 40% or so,
meaning that more than half the time, it's wrong.

How's YOUR accuracy on your traffic? Am I an isolated case?

_Pnina Gersten_

2007-08-23, 7:33 am

> How's YOUR accuracy on your traffic? Am I an isolated case?

Another related question is WHERE do they get the traffic information
anyway?

Do they have an army of ears around the world listening and reporting?

Or is there a central service that does this?

How?

Brevetodes

2007-08-23, 7:33 am

"_Pnina Gersten_" <pd53@sbcglobal.net> wrote in message
news:J6azi.34554$2v1.21540@newssvr14.news.prodigy.net...
>
> Another related question is WHERE do they get the traffic information
> anyway?
>
> Do they have an army of ears around the world listening and reporting?
>
> Or is there a central service that does this?
>
> How?

This is not a Garmin service at all. It depends on what country you're in
and what local services are offered there. Here in Belgium we have two (in
fact 3) different languages (in fact 3) and they cover only their own
territory.You can imagine the quality of info around Brussels, where it
depends on what station you're tuned on.
Anyway your experience with TMC is about the same over here. Traffic info is
sometime right sometimes obsolete.
Google for TMC and RDS, you will find a lot of information.

Brevetodes

2007-08-23, 7:33 am

"_Pnina Gersten_" <pd53@sbcglobal.net> wrote in message
news:J6azi.34554$2v1.21540@newssvr14.news.prodigy.net...
>
> Another related question is WHERE do they get the traffic information
> anyway?
>
> Do they have an army of ears around the world listening and reporting?
>
> Or is there a central service that does this?
>
> How?

sorry a word missing:

This is not a Garmin service at all. It depends on what country you're in
and what local services are offered there. Here in Belgium we have two
providers free (in
fact 3) and different languages (in fact 3) and they cover only their own
territory.You can imagine the quality of info around Brussels, where it
depends on what station you're tuned on.
Anyway your experience with TMC is about the same over here. Traffic info is
sometime right sometimes obsolete.
Google for TMC and RDS, you will find a lot of information.

Pegleg

2007-08-23, 10:33 am

On Thu, 23 Aug 2007 06:23:54 GMT, _Pnina Gersten_ <pd53@sbcglobal.net>
wrote:

>I was just wondering how people felt the accuracy (hence usefulness) of the
>traffic reporting is on the Garmin nuvi GPS.
>
>I bought a nuvi a few weeks ago and drove about a thousand miles so far and
>have found the traffic reporting to be, well, just so so.

You didn't say what country you are in...that would help! Also, what
service are you using and which model Nuvi?

_Pnina Gersten_

2007-08-23, 10:33 pm

On Thu, 23 Aug 2007 07:30:11 -0700, Pegleg wrote:
> You didn't say what country you are in...that would help! Also, what
> service are you using and which model Nuvi?

USA. Nuvi 660. Whatever service comes with it.

Woody

2007-08-23, 10:33 pm

You mean Garmin doesn't have spotters on every road in the US to give you
instant road conditions. What a rip off. Traffic jams are dynamic and come
and go faster than any on line database can report them.

"_Pnina Gersten_" <pd53@sbcglobal.net> wrote in message
news:kxozi.3362$JD.57@newssvr21.news.prodigy.net...
> On Thu, 23 Aug 2007 07:30:11 -0700, Pegleg wrote:
>
> USA. Nuvi 660. Whatever service comes with it.

Pegleg

2007-08-23, 10:33 pm

On Thu, 23 Aug 2007 23:14:24 GMT, _Pnina Gersten_ <pd53@sbcglobal.net>
wrote:

>On Thu, 23 Aug 2007 07:30:11 -0700, Pegleg wrote:
>
>USA. Nuvi 660. Whatever service comes with it.

The 660, I believe, uses the GTM 20 FM Traffic receiver (a Garmin
product that retails for about $200 if purchased separately). The
source of the information is totally unpredictable and of questionable
reliability depending upon where you are at, being primarily limited to
larger metro areas.

The following is a quote from the Garmin site:

"Traffic services are available only in select cities where coverage
exists. A subscription may be required to enable traffic service:

* Throughout most of Western Europe, basic TMC data is a free public
service, accessible through a number of providers.
* In France and the UK premium service requires a subscription.
* In the U.S., a subscription to the Total Traffic Network is
required."

Total Traffic Network, is a division of Clear Channel Radio, and Inrix,
Inc.

Check out:

http://www.realtimetraffic.net/

for coverage maps.

Pegleg

2007-08-23, 10:33 pm

On Thu, 23 Aug 2007 23:22:47 GMT, "Woody" <TheDuck@pond.net> wrote:

> Traffic jams are dynamic and come
>and go faster than any on line database can report them.

Not necessarily true given pavement monitoring systems which reflect
traffic flow speeds as they change and other monitoring systems.

Mike Henry

2007-08-25, 10:33 am

"_Pnina Gersten_" <pd53@sbcglobal.net> wrote in message
news:_J9zi.34553$2v1.8270@newssvr14.news.prodigy.net...
>I was just wondering how people felt the accuracy (hence usefulness) of the
> traffic reporting is on the Garmin nuvi GPS.
>
> I bought a nuvi a few weeks ago and drove about a thousand miles so far
> and
> have found the traffic reporting to be, well, just so so.
>
> Sometimes it's nice that it says "45 minute delay" because I then know
> there is really "center lane blocked" or "accident" or "construction",
> etc.
>
> But, the five and ten and fifteen minute delays seem to vaporize by the
> time I get to them.
>
> What I've found myself doing is not trusting the traffic and crossing my
> fingers by not detouring when I could, and sometimes running into the
> bottleneck (although it never seems to be as bad as they say it is) and
> THEN doing a detour around if I can.
>
> Basically, I'd roughly give the traffic accuracy a score of 40% or so,
> meaning that more than half the time, it's wrong.
>
> How's YOUR accuracy on your traffic? Am I an isolated case?

I think that one of the major problems with the traffic routing is that
there is no indication of how much time is saved by taking the suggested
route over that expected by other available routes. The Nuvi software may
decide that taking side streets can save 15 seconds over an Interstate route
and has no way of knowing that traffic delay along those side streets are
far longer than whatever is happening on the Interstate. That scenario has
bitten me a couple of times and the side street route probably cost me 15-30
minutes compared to the Interstate route. There's probably no good way to
implement it on the Nuvi, but it would be nice to be presented with a list
of alternate routes and the estimated travel times for each. The "Detour"
feature is next to useless for that purpose in my experience.

I find that the traffic info is generally pretty accurate on Interstates in
urban areas, even at rush hour, but that the Nuvi is very optimistic on
routes along side streets at almost any time of day or in any geographical
location. It would be really nice if the Nuvi had a feature that could set
to adjust "average" speed along surface streets. It seems to assume that
the driver will average whatever the speed limit is along those streets and
completely ignores time lost at stop signs or street lights, not to mention
the odd accident or other problem along those routes.

The transmitter reception also seems to be quite poor at anything over 10
miles from the transmitter, at least here in the Chicago area with MSN
Direct on a Nuvi 680, but at least that is better than the receiver for a
Nuvi 350 which I never could get to work at all.

Mike

Jack Yeazel

2007-08-25, 3:33 pm

_Pnina Gersten_ wrote:
>
> On Thu, 23 Aug 2007 07:30:11 -0700, Pegleg wrote:
>
> USA. Nuvi 660. Whatever service comes with it.

The nuvi 660 and 680 use entirely different data sources and
also present the data differently... We have some
comparisons in:
http://gpsinformation.info/nuvi/660/660.html

At times, one is more accurate than the other, so no
conclusions have been drawn until we can do more
simultaneous testing...

--
Jack

Get general GPS information at:
http://www.gpsinformation.net/

mike vore

2007-08-28, 10:33 pm

I've found that traffic delay warnings on broadcast radio, and some of the
state highway signs is mostly way our of date. Many times I had to make a
drive on the Capitol Beltway (I-495) from MD into VA near rush hour. The
overhead signs always seemed to warn of blocked traffic, when there was grid
lock only half of the times. The local PBS station's "Shadow Traffic Report"
was even more inaccurate, they were quoting "x minute delay" in the same area,
most of the time I'd just sail through.

I really doubt most traffic reports I see/hear. I don't know how a GPS based
system can be any better.

--
Mike Vore
http://www.OhMyWoodness.com
http://www.OhMyWoodness.com/blog (new - update your Bookmarks)

Mike Henry

2007-08-29, 4:33 am

"mike vore" <mvore@verizon.net> wrote in message
news:WV4Bi.141$Xg.66@trnddc06...
> I've found that traffic delay warnings on broadcast radio, and some of the
> state highway signs is mostly way our of date. Many times I had to make a
> drive on the Capitol Beltway (I-495) from MD into VA near rush hour. The
> overhead signs always seemed to warn of blocked traffic, when there was
> grid
> lock only half of the times. The local PBS station's "Shadow Traffic
> Report"
> was even more inaccurate, they were quoting "x minute delay" in the same
> area,
> most of the time I'd just sail through.
>
> I really doubt most traffic reports I see/hear. I don't know how a GPS
> based
> system can be any better.

You may well be right. It seems to me that the value of the data depends on
the latency. Software *should* be able to render a near continuous update
of traffic conditions but I've no idea how often the GPS receiver receives
that data let alone how current it is. Does anybody know how commercial
radio compares in general to GPS traffic receivers in that regard?

I do know that the radio announcers usually speak too fast for me to follow
accurately.

Mike

Pegleg

2007-08-29, 4:33 am

On Wed, 29 Aug 2007 02:33:26 GMT, mike vore <mvore@verizon.net> wrote:

> I don't know how a GPS based
>system can be any better.

It is not GPS based! It utilizes a device that receives the information
via FM and it is only being played through the GPS unit. I explained
that in my previous post. Nothing in that post disputed the timeliness,
or lack of, with regard to the posts.

duke93duke93@gmail.com

2007-08-30, 3:33 pm

On Aug 29, 1:04 am, Pegleg <Peg...@usnavyret.mil> wrote:
> On Wed, 29 Aug 2007 02:33:26 GMT, mike vore <mv...@verizon.net> wrote:
>
> It is not GPS based! It utilizes a device that receives the information
> via FM and it is only being played through the GPS unit. I explained
> that in my previous post. Nothing in that post disputed the timeliness,
> or lack of, with regard to the posts.

I have a 660 and utilize the traffic feature in Hartford, CT on I-91
and I-84.

My issue is that the traffic is ALWAYS reported to be a "1 minute
delay."
If there is any traffic, it is reported as a 1 minute delay regardless
of the severity.
The most humorous ScreenShot that I have states "Accident with 3 lanes
closed.
1 minute delay." I-91 has only three lanes at this point.

Garmin and Clear Channel do not have answers for this. Has any one
else experienced
anything similar ?

Thanks.

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