City Navigator V8 Street Address Offset

[Mimo1]

Is anybody noticed that on City Navigator North America V8 the street address (civic numbers) are offset? They are so offset that at the end of the street there is numbers that are not existing. It's like if they put too many lots per street.

Edited July 9, 2006 by Mimo1

[+Munin]

Sure, the street I live on is like that - City Select and City Navigator (and Google Maps, and Yahoo Maps, and MS Streets & Trips, and every other mapping program I've seen) believes the houses on my street go up to #99. In reality, the highest number is #32. My guess has been that "99" is a default value that's put in the map databases for streets where nobody's bothered to physically drive down the street to find the correct range on the house numbers. There's actually a fair number of (mostly small, residential) streets in my area that are the same way - max address shows as 99, but there's far fewer than 99 lots on the actual street.

[Mimo1]

I'm living at 115 and at the end of the street it's the 123. But on cnna it's 199. It looks as you said, the are using bunch of 99 depending of the length of the street.

[kerecsen]

I'm living at 115 and at the end of the street it's the 123. But on cnna it's 199. It looks as you said, the are using bunch of 99 depending of the length of the street.

 

Report the bug to them, and hopefully they'll fix it. By the way, the map doesn't contain individual addresses, it only has an address range for each street segment (one range for the even side, another for the odd side). So if you have empty lots at the end of the street, or one lot that occupies a long stretch, the numbering will be incorrect regardless of what they do. Their only goal is that if you enter an address, the cursor comes out reasonably close to the target house. If you randomly point to locations on the street, the numbers will likely be bogus.

[GeoidPS]

All of the features with addresses are located along the road. The buildings in a shopping mall are not shown in the actual location, but along the road. This is not good when navigating because the navigtor does not know where the entrances are.

[stevesisti]

Is anybody noticed that on City Navigator North America V8 the street address (civic numbers) are offset? They are so offset that at the end of the street there is numbers that are not existing. It's like if they put too many lots per street.

 

The actual street address is calculated by by taking a "starting" number and an "ending" number and evenly, by distance, distributing the numbers over the street length segment. In actuality this has a very poor accuracy in pinpointing a specific street address because common sense tells you "even" spacing between different "properties" rarely, if ever, occurs in "real life". For a street address to be very accurate, the unit would have to have the GPS coordinates for each address, which it doesn't have and won't have for the foreseeable future. In practice, when finding a specific street address, you should consider the indicated address as an approximation, and visually look for the address when you get "close". I have seen many addresses that by coincidence, are remakably close to the actual location (pretty much even spacing of properties) and I have seen addresses that weren't even close. No sense in calling Garmin or anyone else regarding the issue. The current mapping units just don't deal with specific addresses...only an approximation by the method described above.

Edited July 9, 2006 by stevesisti

[+Sputnik 57]

Imagine how much memory it would take to assign coordinates to every individual address through out the US (or the world, for that matter). Geocoding simplifies this by using line segments and approximate addresses, as outlined above. Virtually all geocoding services do this, including NaviteQ, to which Garmin subscribes.