Route Accuracy

[castironchef]

I've spent hours slogging through the TT 720 vs Nuvi 760 battlefield, reading how one unit is better than the other. There was even a thread on another list where 660 users compared how close their routes got them to their actual destinations. (usually around 13') There were several comments about the TT sending drivers to destinations other than they had programmed and I haven't come across anything that talks about how great the TT accuracy is. Please share your experiences to aid me in making my decision. TIA.

 

[eldorado]

All I can say with my One XL it gets me where I want to go and I can not say just exactly in ft how close it comes to the address or location I'm looking for, but it gets me close enough, I live a kinda a rural area and there have been times when it wants to takes me somewhere I don't know (this does happen occasionally) so I have to kinda know where I'm going, but when I go to the big city (lol) it works just fine.............

 

[canderson]

There were several comments about the TT sending drivers to destinations other than they had programmed and I haven't come across anything that talks about how great the TT accuracy is. Please share your experiences to aid me in making my decision. TIA.

Apart from a few times where there's a discrepancy in the TeleAtlas map address vs. actual location of a building, I've never been sent astray, and then only by a house or two. It lands me directly into my own driveway.

ALL normal weirdness in destination precision is, I can assure you, a map issue. One of my other purposes for my 720 is geocaching, and there have been times where I've come up upon an obvious location for an urban cache with the 720 and not even bothered to turn my Garmin handheld on. That's no knock on the Garmin at all, it was just that the 720 nails the latitude/longitude so well that more precision wasn't required. Given a correct location to start with, the TomTom units do just fine.

One could then raise the question as to whether the TeleAtlas vs Navteq maps are better, and for that, it would depend entirely upon where you are. Both have regional deficiencies and strong points.

 

[GarCor]

One of the resasons TomTom is more percise is it use of navStar Sat's. I don't5 believe Garmin use these sats but I am not sure.
Look_here

I did a comparison with my 4 year old Magellan & my TT Go 920 as to sat's connected and the Magellan connected to 5 and the TT to 9

 

[canderson]

One of the resasons TomTom is more percise is it use of navStar Sat's. I don't5 believe Garmin use these sats but I am not sure.
Look_here

I did a comparison with my 4 year old Magellan & my TT Go 920 as to sat's connected and the Magellan connected to 5 and the TT to 9

You may be confusing the 24 military satellites with the two that the FAA put up that provide WAAS functionality to improve the accuracy of information from the 24.

Those two provide a continuous fudge factor for clock drift and other issues with the other 24. Since the FAA knows exactly the location of their receivers, they are able to send back exceptionally accurate correction data to their own two satellites, and that information can be used to refine the information that a GPSr receives from the 24 others... providing the GPSr can pick up those signals as well. That data can significantly improve the accuracy radius.

AFAIK, TomTom has not been making any use of WAAS correction data on their units. What little I know of the specific GPS receiver chipsets they have used would indicate that they do not.

WAAS information at this link: http://en.wikipedia.org/wiki/WAAS

 

[sageuvagony]

As annoying as the TomTom can be sometimes, it has never failed me getting me to any location. Especially when it comes to driving to a POI, like Home Depot or something, when it says "you have reached your destination" it doesn't always take me to the EXACT spot, but as long as I take a look around me, I always see the business.

It was only 2 times last week in Tallahassee where the TomTom lead me to 2 POI locations that were abandoned. The TomTom was correct when leading me to the locations, but both KFC and Applebees were both abandonded. I arrived to the KFC and saw that it still had the signs and all, but was business was all boarded up. When I arrived at Applebees, the signs were there too and all, but when I walked up to the business there was a sign that said "We have moved"

Just a small case of outdated POIs.

I can't imagine going anywhere without my TomTom now.

 

[Barcard]

As you've probably determined, accuracy of maps is one issue and routing is a separate issue.

Whether Teleatlas (TomTom) or Navtech (Garmin) are more accurate maps will depend on where you live or travel to.

On the other hand, routing algorithms are developed by the individual GPS manufacturers, and even if the maps are the same in your area, a TomTom and a Garmin might route you differently.

You can go to Teleatlas' and Navtech's web sites to check the maps in your area. The only way to test routing, ease of use, performance, etc., is to try a unit out, and check the store's return policy before you buy. Good luck.

 

[mvl]

As far as mapping goes:

You can check out google maps (which will match TeleAtlas/Tomtom) and Yahoo maps (which will match Navteq/Garmin) to see which is better in your area.

I bought a tomtom two years ago because it was the only GPS that allowed live editing of the maps (remove and change, but not add, streets). Other vendors didn't have this capability two years ago, and I still think none of them do.

Teleatlas was reputed to have worse maps for the USA two years ago, but they have supposedly made huge strides the last few years due to the tomtoms supplying mapshare data back to them.