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Maps

Here you'll find a collection of links, reviews, notes for Maps used in both
standalone GPS receivers and PocketPC Navigation Software

Map Sources
Summary table of maps used by GPS/Navigation Software

Opinions
Reporting errors in maps


 

Map Sources
By Description Coverage Update Frequency Comments
NavTech Highly accurate maps updated by a specialized firm U.S. and Europe Quarterly
bulletThese maps are generally regarded as being the best
bulletIn 2002, NavTech completed its coverage of the whole US territory
bulletAlthough I haven't experienced this first hand, it seems that NavTech have some fairly restrictive licensing policies in terms of how the data they provide is aggregated and used. This might account for some of the "quirks" in current programs, i.e. price of programs using NavTech, size of maps, highway maps, etc...
bulletIf you've found errors in NavTech maps, you can report them here
 
TeleAtlas Highly accurate maps updated by a specialized firm U.S. and Europe ?
bulletThese maps are generally considered to be a close second to the above
Tiger Used by the US government for Census purposes U.S. -
bulletThese maps have a bad reputation as being quite inaccurate and I must say that in the US on my Magellan M330, I'm always shown half-a-block from my actual location. Rather annoying...


 

Summary table of maps used by GPS/Navigation Software
By Tiger (US only) Navtech TeleAtlas Other
PocketPC Navigation Software -
bulletDestinator
bulletMapopolis
bulletNavman 3420 - USA
bulletNavman 3400 - Europe
bulletDistefora
bulletID Navigator
bulletMapviewer
bulletPharos Ostia
bulletTeletype
bulletTomTom
bulletCoPilot
bulletDelorme HH Xmap
Laptop/Desktop Navigation Software -
bulletMicrosoft
bulletStreets & Trips USA
bulletAutoroute Europe
bulletMappoint USA
bulletMappoint Europe
bulletRoute 66 Europe

-

bulletDelorme
bulletStreet Atlas
Standalone GPS
Receivers
-
BaseMaps

 
bullet

Garmin
bullet

all mapping GPSr's

bullet

Magellan GPS Receivers
bullet

M330

bullet

Meridian

bullet

SporTrak

bulletGarmin ( 1 auto-routing info ?)
bulletGPS V
bulletStreetPilot III
- -
Standalone GPS
Receivers
-
Optional Maps
bullet

Garmin
bullet

Roads & Recreation USA

bullet

Magellan
bullet

MapSend Streets USA

bulletGarmin
bulletCityNavigator for SP III
bulletCitySelect for GPS V
bulletMetroGuide Europe
bulletMetroGuide Canada
bulletMetroGuide Australia
bulletRoads and Recreation Europe
bulletMagellan
bulletMapSend Streets Europe
bulletGarmin
bulletMetroGuide USA
bullet

Garmin
WorldMap - Data from circa WWII apparently
Not that bad though? ...hum..

Built-in Car Navigation Systems -
bulletAlpine NVE-N852A
bulletMagellan 750 Nav
bulletPioneer NAV-SYS900DVD
bulletVDO Dayton MS5000
bullet

Blaupunkt TravelPilot

bullet

Mannesmann VDO

bullet

Philips Carin

bullet

Clarion

-

1 Dale DePriest (website) wrote to say he thought Garmin might only be using autorouting data from NavTech and Tiger for the rest. Makes sense to me, thanks Dale !


 

Opinions

bulletMap quality
By Joe Mehaffey - from "Automatic Address to Address Routing GPS Automobile Navigators  What to expect from the currently available equipment" rev. 07/10/02

"Maps:  The maps required for a GPS automatic navigator which can design you a route from address A to address B are highly specialized.  In addition to the need for highly accurate maps,  the map database must contain a large amount of data about highway and roads.  This road information includes average travel speed classifications, one way streets,  names and road numbers of all streets,  expressway ramp details, and dozens of other programming details.

One of the main disappointments of some people is that the maps are NOT PERFECTLY ACCURATE or they find their favorite street in a subdivision is missing.   Forget it.  None of the currently available maps are perfectly accurate.  And they do not have to be perfectly accurate for the user to receive quite satisfactory results.  For instance,  roads and highways are being built,  moved,  and renamed and renumbered all the time.  Many municipalities are lax in getting their changed map data to the proper agencies and are in arrears for YEARS.   Generally speaking,  maps appear to be from 2 to 4 (or even more) years old.  Some roads (even Interstate Highways) can be out of position by hundreds of feet in spots.  (So many roads,  so few map makers.)  As a result,  you cannot pick up a single printed or electronic map that is completely accurate.  Some ARE better than others.  NavTech and MetroGuide II maps are among the best.  BUT!  Don't expect perfection!  You won't get it.

NOTE:  The above comments apply to the REALLY GOOD quality maps by NavTech and Etak (note - I think he's referring to TeleAtlas who purchased Etak) and a few others as used in Car Navigation systems.   The "not so good" quality maps (such as Garmin R&R,  Lowrance Streets, and Magellan MapSend Streets,  the WorldMap offerings and basemaps in handheld units)  can have much larger errors.  I have seen roads displaced by almost half a mile in a few spots.  Sometimes the shoreline on basemaps is displaced so you seem to be driving in the water.  Forget it!  Things are improving every day,  but perfection is quite a ways off"

 

bullet

Map source, "snap to road" and naming
"
I want to mention a couple of points that you may or may not know about navigable digital maps.

Tiger data is the starting point for NavTech and TravRoute's digital maps. The positional accuracy is in the neighborhood of 6-10 meters. It used to be worse.
To display a vehicle Icon on a road segment the developer must make the decision to snap it to the road line. What do you do when the vehicle is not on the road, say in a large parking lot? In addition the combined interaction of the maps positional accuracy and GPS error can often fall outside the developers criteria for snapping to a road line.

Road segments typically have 3 name fields. One of the fields is supposed to be the locally preferred name but, displaying this field is not always the best choice. The I40/CORONADO HWY example you used is a case where the developer is displaying 2 of the field names. You will probably find that as you drive I40 the secondary name changes with each new municipality. Unfortunately, the three name fields and their level of importance is the only information the developer has to draw from. And, to further exacerbate the issue sometimes there are no names."- posted by SteveT on the PocketPCPassion message board
 

bullet

Data Collection
By PanEuropean in the
sci.geo.satellite-nav newsgroup

"Database Accuracy:  Garmin, unfortunately, is at the mercy of the people (usually governments) who provide the _vector_ map data.  I know from extensive riding experience that the map data for Switzerland, Germany, Belgium and Luxembourg is absolutely fantastic - every single street, path, and cart track in those countries are listed, with great accuracy.  The only problems that exist in those (highly developed) countries are 'typographical' - meaning, by example, I have found a few places where
pedestrian walkway was coded to be a road suitable for vehicles, etc.  Get down south, into Spain, Portugal and Italy, and the quality of the map data falls way down.  Heck, in Spain, big 4 lane autopistas that have been open for over a year are not on the database, compared to Switzerland, where little roundabouts in residential neighborhoods that were built in spring 2002 ARE in the database.  In Lisbon, all the streets in the city are listed - but the fact that half of them are one way is not listed.  There's no way that NavTech surveyed these Swiss residential neighborhoods in the 2 months between roundabout construction and release of the European CD's that
support auto routing - that information must have been supplied to NavTech by the Swiss Federal Mapping Office, most likely in advance of the actual construction of the roundabout.

AFAIK, Garmin buys the cartographic data from NavTech, and NavTech starts their data collection process off by buying _vector_ street and road data from the federal governments of the various European countries.  NavTech then sends their vehicles out to drive the main roads and collect additional data, such as signage, speed limits, weight restrictions, etc. to refine the information even further.  I don't think NavTech has got around to doing a lot of their own data collection work in the Southern European countries yet.  There will be an update released for CN Europe this fall, that will help some and will correct the gross errors, but really high quality, complete coverage for the Southern European countries will depend, for the most part, on the federal governments of these countries compiling accurate and complete _vector_ data describing their roadways.  Don't bet on this happening overnight - 5 years is my personal guess, and only if they get EC funding to do it."

 

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