Garmin GPS - GPS vs MapSource routing

Author

GPS vs MapSource routing

Jeffrey Kaplan

2007-04-25, 10:33 pm

I have a c330, it has City Navigator NT v8 preinstalled. After
contacting Garmin about the lack of included desktop software for
waypoint management, they sent me a copy of MapSource with City
Navigator NT v8 for my PC. It arrived today.

In futzing around with it, I asked it to create a route from my HOME to
a waypoint/favorite two states over. Since I am +at+ HOME right now, I
turned on the GPS and asked it to create a route to the same place.
Avoidances are the same, vehicle type is the same, and both are set to
route via shortest time.

They came up with two different routes.

Oh, most of the routing is identical, but MapSource's route cuts a
corner by taking a connecting highway through the center of a city and
the GPS' route ignores the connector and goes for the interchange
between the first and second highways directly. (If you're at all
familiar with Massachusetts, or want to look it up yourself, it's I-495
southbound and I-90 westbound - MapSource cuts the corner by taking
I-290 through Worcester and the GPS doesn't.)

If the two are working off of the same data, why the difference?

--
Jeffrey Kaplan www.gordol.org
The from userid is killfiled Send personal mail to gordol

Peter's Top 100 Things I'd Do If I Ever Became An Evil Overlord, #75. I
will instruct my Legions of Terror to attack the hero en masse, instead
of standing around waiting while members break off and attack one or
two at a time.

Jørgen L.

2007-04-26, 4:33 am

> If the two are working off of the same data, why the difference?

Your speed data is different, your 330 is learning how fast or slow your
driving.

you can set these data in mapsource in option, route, and then speed.

Regards Joergen
Denmark

Jack Erbes

2007-04-26, 7:33 am

Jeffrey Kaplan wrote:

<snip>
> If the two are working off of the same data, why the difference?
>

There are settings under Edit > Preferences > Routing in MapSource that
are not coming into play in route generation on the c330.

When you upload that route to a c330, all you are sending to the GPS is
the final destination as a Favorite. When you activate the route on the
c330 it knows nothing but the destination, it has no clues at all about
what transpired previously in MapSource.

I think there is some subtle difference or interplay with settings and
road vectors in MapSource that is not present in the c330 software.

I know that particular route well and generally use I-290 to get from
I-495 to I-90. I just created route in MapSource from Ellsworth, ME to
Hartford, CT and it did not route me via I-290. That was with the Edit
> Preferences> Routing > Road Selection slider at the default position
midway between "Prefer Minor Roads" and "Prefer Highways". But if I
slide it all the way to the right towards "Prefer Highways" and
recalculate the route, it will give me a new route and take me via I-290.

Looking at the route properties for that route before and after moving
the slider shows both routes to be the same. It lists only Ellsworth
and Hartford as "map points". Nothing more. So the route through
Worcester is only in program memory in MapSource.

If I upload the route to my 2610 or 76Cx I may or may not get routed via
Worcester depending on the settings on the two receivers. It may even
be that I would have to insert a waypoint in the route (on I-290 near
Worcester) to get the preferred routing every time the route is activated.

So if I plan a route in MapSource and it does not go the way I want to
go, I start placing waypoints on the roads I want to take and adding
those to the route until it gets it right. MapSource will include my
waypoints in the routes uploaded to my 2610 and 76Cx and I seldom if
ever find the routing on the GPS receivers to be any different than it
was in MapSource.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Jeffrey Kaplan

2007-04-26, 12:33 pm

It is alleged that Jack Erbes claimed:

> There are settings under Edit > Preferences > Routing in MapSource that
> are not coming into play in route generation on the c330.
>
> When you upload that route to a c330, all you are sending to the GPS is

I am not uploading the route.

> the final destination as a Favorite. When you activate the route on the

The destination is already a favorite.

> c330 it knows nothing but the destination, it has no clues at all about
> what transpired previously in MapSource.

At this point, the only communication between the two was to download
my favs/waypoints from the c330 to MapSource.

> I think there is some subtle difference or interplay with settings and
> road vectors in MapSource that is not present in the c330 software.

That I can believe. But why would that be? They've got the same map
data.

> I know that particular route well and generally use I-290 to get from
> I-495 to I-90. I just created route in MapSource from Ellsworth, ME to
> Hartford, CT and it did not route me via I-290. That was with the Edit
> midway between "Prefer Minor Roads" and "Prefer Highways". But if I

That's where mine is, I did not change the slider as I am unsure how it
will effect things. Depending on where I'm going, and the specific
surface roads and highways in question will determine which I prefer.
Forex, from Dover, NH to Portsmouth, NH, I generally prefer to use the
Spaulding Tpk only where I have to, since it's the only road bridge
across the water from Dover Point to Newington. But to anywhere beyond
Portsmouth either north or south, I'll generally just take the
Spaulding the whole way from Dover.

> So if I plan a route in MapSource and it does not go the way I want to
> go, I start placing waypoints on the roads I want to take and adding
> those to the route until it gets it right. MapSource will include my
> waypoints in the routes uploaded to my 2610 and 76Cx and I seldom if
> ever find the routing on the GPS receivers to be any different than it
> was in MapSource.

I was more curious than anything else, this particular difference isn't
really a problem. If I go off-route, the c330 will recalculate.

--
Jeffrey Kaplan www.gordol.org
The from userid is killfiled Send personal mail to gordol

"Oasis! Bring me Torg's head! Hmmm, well, it didn't necessarily have
to be attached. We'll have to work on that." "If it's any
consolation, this hurts a lot." Dr. Steve and Torg, 'Sluggy Freelance'

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