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Distance

 

I was sure this was answered before, no luck in finding it though. I noticed on my trip to Oregon how annoying the distance shown was. Why don't these figures match? An example is one of my favorites called Oregon Zoo. It tells me it's South from my place and 259.5 Miles from here. I click it and a little window behind the GO! button comes up and tells me it's 311.4 Miles plus other info. Quite a difference. I hope no one tells me the first one are Crow miles.

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nüvi®3790LMT nüvi®3590LMT| We do not live in Igloo's, and do not ride to work on snow mobiles

From Garmin

Question : Why is the distance listed next to my 'Favorites' and 'Recently Found' locations wrong on the nüvi?

Answer:

The distance listed to the right of the locations is a straight line route. So it is displaying an estimated distance in a straight line from where you are to the destination selected. If you want the actual distance you will be traveling, simply press Go. Once you push Go, the unit calculates the route and determines which roads you will be taking to get to the destination. After that is completed you should be on the Map screen and in the bottom left corner you will see Arrival, touch Arrival. You should now see a mileage reading in the top right corner next to checkered flag. The distance listed there is the actual distance you will be traveling.

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Nüvi 255W born on 602117815/nüMaps Lifetime North America

?

So they are saying exactly what i didn't want to hear. It's the way the Crow fly's. You know what? I ain't buying into that, i could be wrong. That's 51.9 miles difference. I would think that figure to me a bit more. How can we test this?

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nüvi®3790LMT nüvi®3590LMT| We do not live in Igloo's, and do not ride to work on snow mobiles

Go to

http://www.movable-type.co.uk/scripts/latlong.html

and plug in coordinates - get distance - then drive it via the instructions given by your GPS.

Of course that's the hard way but WTH - gives you something to do !

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MrKenFL- "Money can't buy you happiness .. But it does bring you a more pleasant form of misery." NUVI 260, Nuvi 1490LMT & Nuvi 2595LMT all with 2014.4 maps !

No need to test

Yes, as the crow flies and road miles can be different by 51.9 miles. It is what it is.

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*Keith* MacBook Pro *wifi iPad(2012) w/BadElf GPS & iPhone5 + Navigon*

.

Why aren't you "buying into that"?

It's the truth.

Test it by doing it in MapSource.

Compare the straight line distance to the routed distance.

There's an idea

Motorcycle Mama wrote:

Why aren't you "buying into that"?

It's the truth.

Test it by doing it in MapSource.

Compare the straight line distance to the routed distance.

.

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nüvi®3790LMT nüvi®3590LMT| We do not live in Igloo's, and do not ride to work on snow mobiles

yes the first distance shown is as the crow flies

If I select the Mt. Lemmon ski area when at home it shows about 25 miles but when I select go it says 51 miles and that is actually the distance needed to actually drive there. The ski area is about 25 miles from my house to the ski area if I draw a straight line between the 2 of them on a map.

So yes the first distance shown is as the crow flies until you select go and the actual drive is calculated.

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nüvi® 3790LMT - Samsung Galaxy Note 8.0 with Garmin Viago Maps - GM Built-in Navigation system

Or

And/Or Google Earth.
But MapSource can use the same map as your unit's map.

Speed2 wrote:
Motorcycle Mama wrote:

Why aren't you "buying into that"?

It's the truth.

Test it by doing it in MapSource.

Compare the straight line distance to the routed distance.

.

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It's about the Line- If a line can be drawn between the powers granted and the rights retained, it would seem to be the same thing, whether the latter be secured by declaring that they shall not be abridged, or that the former shall not be extended.

Oh well

Using Mapsource, its close enough, 250 miles. Where do i find the icon again that tells me i'm in Crow mode when i use that screen? rolleyes

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nüvi®3790LMT nüvi®3590LMT| We do not live in Igloo's, and do not ride to work on snow mobiles

Think geometrically

Speed2 wrote:

So they are saying exactly what i didn't want to hear. It's the way the Crow fly's. You know what? I ain't buying into that, i could be wrong. That's 51.9 miles difference. I would think that figure to me a bit more. How can we test this?

311.4 miles is 20% more than 259.5 miles.

Now think of a square city block or a rural township with roads on a 1-mile square with the corners labeled A, B, C, D:

A B

C D

If travelling from Point A to B which is in a straight line with no turns along the square, the crow-flies and the road-travelled distance will be identical. But if looking to route from point A to D at the opposite corner of the square, the road-travelled length will be a smidge over 41.4% longer than the crow-files distance. In the real world with some angled and curved roadways, the difference between crow-flies and road-route will fall between the 0% and 41% increase. So your example of a 20% increase above crow-flies is a very typcial result to be expected in the real world falling roughly midway between 0 and 41%.

wink Of course, this is based on a 2D map. If we add curvature of the earth and look towards a large route (say Inuvik NWT Canada to Quito Ecuador) then I wonder of we're comparing roads-travelled to crow-flies distances or if we should be comparing roads-travelled to mole-tunnelling distances...

Too many icons

Now i need a mole icon also? laugh out loud

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nüvi®3790LMT nüvi®3590LMT| We do not live in Igloo's, and do not ride to work on snow mobiles

Holey moley

Speed2 wrote:

Now i need a mole icon also? laugh out loud

A great example of differences between crow-files and roads-travelled is from the Visitor Center at the South Rim of the Grand Canyon to the Visitor Center at the North Rim.

I've heard stories of family vacationers arriving at the South Rim late in the evening only to find their lodging reservation is at the North Rim and the shock experienced when told of the driving miles and time needed to get to their room even though a crow (better yet, a raven) will have a much shorter trip!

So a roads-travelled length under some circumstances will be so-much more than the crow-flies....

.

Speed2 wrote:

So they are saying exactly what i didn't want to hear. It's the way the Crow fly's. You know what? I ain't buying into that, i could be wrong. That's 51.9 miles difference. I would think that figure to me a bit more. How can we test this?

How else would you have them tell you the distance between where you are to the indicated waypoint?

Would you have the navigator calculate the road distance by working out a route for each and every waypoint in the display? Do you really want to die of old age before you get those numbers?

Get real - the only metric they CAN use is a straight line - and since roads rarely are straight, let alone that you have to take several different ones, the driving distance, which would be dependent on your selected preferences and (if you have one and some of the roads are monitored) traffic, making the route potentially time-of-day dependent as well.

So yes, they show straight line distances and expect the operator to then calculate the driving distance and time.

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Currently have: SP3, GPSMAP 276c, Nuvi 760T, Nuvi 3790LMT, Zumo 660T

.

When you pull up a list of locations (Custom POIs, Waypoints, whatever) on the GPS unit, the distance on the list will be displayed as a straight line mostly in the interest of speed in displaying the list.

The unit does NOT apply your Routing Preferences until you press Go!

If the list attempted to show the Routed Distance for every location on the list, it would take an EXTREMELY LONG TIME to display the list.

Curvature of the earth !!

Reminds me of when I realized how important the curvature of the earth was, even to a crow. laugh out loud

Was when we were delayed by two days in Calgary on a trip from D.C. to Fairbanks, AK.

Although I did some route planning before we left, I was shocked (well, surprised) to find out in the hotel that Calgary was the halfway point. surprised

Too much Google Earth planning I guess. Didn't pay enough attention to rotating that big ball while looking at roads.

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It's about the Line- If a line can be drawn between the powers granted and the rights retained, it would seem to be the same thing, whether the latter be secured by declaring that they shall not be abridged, or that the former shall not be extended.

Even Over Shorter Distances

Quite a few years back, I worked in NY. Where I lived was 15 miles from my workplace as the crow flies.

If you were to drive from one place to the other the shortest distance possible is over 35 miles-233% as long as the straight line.

Glad I'm doing that commute any more mrgreen

How about

bramfrank wrote:
Speed2 wrote:

So they are saying exactly what i didn't want to hear. It's the way the Crow fly's. You know what? I ain't buying into that, i could be wrong. That's 51.9 miles difference. I would think that figure to me a bit more. How can we test this?

How else would you have them tell you the distance between where you are to the indicated waypoint?

Would you have the navigator calculate the road distance by working out a route for each and every waypoint in the display? Do you really want to die of old age before you get those numbers?

Get real - the only metric they CAN use is a straight line - and since roads rarely are straight, let alone that you have to take several different ones, the driving distance, which would be dependent on your selected preferences and (if you have one and some of the roads are monitored) traffic, making the route potentially time-of-day dependent as well.

So yes, they show straight line distances and expect the operator to then calculate the driving distance and time.

How about you don't give me anything, but N S E or West since the Mileage figure is really useless to me
since I can't drive like the Crow fly's. What reason would one have to use these figures on an Automotive GPS?

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nüvi®3790LMT nüvi®3590LMT| We do not live in Igloo's, and do not ride to work on snow mobiles

.

Speed2 wrote:

How about you don't give me anything, but N S E or West since the Mileage figure is really useless to me
since I can't drive like the Crow fly's. What reason would one have to use these figures on an Automotive GPS?

They already do tell you what direction they are in.

And you want to know how far away they are to get an idea of what's involved even if they can't display the road miles (which they can't).

I suppose they could eliminate the number from the display - or, perhaps it is more reasonable for you to just ignore it if it means nothing to you.

It certainly is useful to me.

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Currently have: SP3, GPSMAP 276c, Nuvi 760T, Nuvi 3790LMT, Zumo 660T

OK

bramfrank wrote:
Speed2 wrote:

How about you don't give me anything, but N S E or West since the Mileage figure is really useless to me
since I can't drive like the Crow fly's. What reason would one have to use these figures on an Automotive GPS?

They already do tell you what direction they are in.

And you want to know how far away they are to get an idea of what's involved even if they can't display the road miles (which they can't).

I suppose they could eliminate the number from the display - or, perhaps it is more reasonable for you to just ignore it if it means nothing to you.

It certainly is useful to me.

Ignoring it, I will have to, but in your last statement you said its "useful". How? What could you possibly use that figure for?

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nüvi®3790LMT nüvi®3590LMT| We do not live in Igloo's, and do not ride to work on snow mobiles

It is quiet annoying to get

It is quiet annoying to get that distance as the crow flies.When on my last trip I always would like to know how far and the estimated time to get to next stop.I can see not being aware of this would cause problems.Luckily I learn this early on from Poi Factory forum.

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Charlie. Nuvi 265 wt and 2597 LMT.

Relative ranking

bramfrank wrote:
Speed2 wrote:

So they are saying exactly what i didn't want to hear....

How about you don't give me anything, but N S E or West since the Mileage figure is really useless to me
since I can't drive like the Crow fly's. What reason would one have to use these figures on an Automotive GPS?

OK, the numeric values are understated in terms of eventual road miles. But the relative crow ranking starting with the closest will likely also be the relative road-mile ranking, so it will offer what's likely to be the closest choice first. Add that to the already-included directional arrows to avoid backtracking and it sounds great to me.

Fine

CraigW wrote:
bramfrank wrote:
Speed2 wrote:

So they are saying exactly what i didn't want to hear....

How about you don't give me anything, but N S E or West since the Mileage figure is really useless to me
since I can't drive like the Crow fly's. What reason would one have to use these figures on an Automotive GPS?

OK, the numeric values are understated in terms of eventual road miles. But the relative crow ranking starting with the closest will likely also be the relative road-mile ranking, so it will offer what's likely to be the closest choice first. Add that to the already-included directional arrows to avoid backtracking and it sounds great to me.

We can go on debating this forever i guess. The direction of travel certainly is useful. The first one being the closest depending how you set the unit up is of course also useful. I still need to go into the actual choice to find out my particulars, hence the crow mileage is just useless and annoying info to me.

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nüvi®3790LMT nüvi®3590LMT| We do not live in Igloo's, and do not ride to work on snow mobiles

Maybe, Maybe not?

Speed2 wrote:

.. hence the crow mileage is just useless and annoying info to me.

I find it useful if I'm on an Interstate (could apply to most roads in Kansas or Oklahoma too, or walking mode I guess) and looking for for the closest fuel, food, or hotel. The odds are that if the arrow points the same direction I've been traveling from or are traveling toward, the closest will be that direction. If I need a guarantee, then I'll press GO and see what it comes up with.

I guess you have to bear in mind that if the road you're on is going north-west, and you have one arrow pointing north-east and one north-west, the one pointing north-west is more likely to be closer to the road you're traveling on, and hence closer to actually get to unless you're walking (with a fuel can?) & can cut through yards. wink

--
It's about the Line- If a line can be drawn between the powers granted and the rights retained, it would seem to be the same thing, whether the latter be secured by declaring that they shall not be abridged, or that the former shall not be extended.

Great Circle Distance

Garmin is using a technique known as spherical triq. to calculate the distance between any two points on earth using known Lat. and Long. coordinates. It's not really a straight line but for practical purposes that is what we say. Using a scientific calculator makes the task really easy.

Yikes...

CraigW wrote:

I've heard stories of family vacationers arriving at the South Rim late in the evening only to find their lodging reservation is at the North Rim and the shock experienced when told of the driving miles and time needed to get to their room even though a crow (better yet, a raven) will have a much shorter trip!

Did that... I believe it was 218 miles, all local roads. Took me near 12 hours.... It's less than 15 miles rim to rim. Just a severe lack of roads. wink

--
Striving to make the NYC Metro area project the best.

Hee!

camerabob wrote:
CraigW wrote:

I've heard stories of family vacationers arriving at the South Rim late in the evening only to find their lodging reservation is at the North Rim and the shock experienced when told of the driving miles and time needed to get to their room even though a crow (better yet, a raven) will have a much shorter trip!

Did that... I believe it was 218 miles, all local roads. Took me near 12 hours.... It's less than 15 miles rim to rim. Just a severe lack of roads. wink

Maybe it's just an urban legend, but given some tourists, this may well be true. When told of what they need to do to get to the lodge on the other rim, they quickly pull out a map and show a bridge across the river right below them that is much closer than the Navajo Bridge near Lee's Ferry that they're being told to use. The bridge they point to is OK for hiking boots and mules, but not their rented Prius.

I ain't buying into that

I think that you need an airplane but even they fly highways in the sky.

Try it in a coastal area

Haven't seen it yet with my 765, I did with a non-Garmin unit, but this "as the crow flies" can be particularly interesting in coastal areas when the search results list the closest locations just a few miles away, only to discover they are across open water from the starting point and are actually dozens of miles away as the road goes. It is understandable, but if unfamiliar with an area you might not immediately realize it. The only solution would be to calculate the route out to get a more accurate estimate of which destination is actually the closest.

Happens all the time for me

I live on Long Island. I do searches on many manufacturer's and retail store's web sites. The distance is really close, until I see the stores are in Connecticut.... Crow fly distance is 10 miles. Road distance is another matter altogether....

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Striving to make the NYC Metro area project the best.

Crows?

CraigW said: "but given some tourists...." I believe those tourists would be the ones whose ears are connected. wink

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"It's not where you start, but where you end up." Where am I and what am I doing in this hand basket?

Approximation

Its an approximation in the list. Imagine the CPU cycles it would take to calculate the driving distance for every location in the list.

Then we would be reading complaints about how slow the GPS is at doing those calculations. rolleyes

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Tampa, FL - Garmin nüvi 660 (Software Ver 4.90), 2015.20 CN NA NT maps | Magellan Meridian Gold

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