Can you trust these POI coordinates?

I have to tell you that from experiance, I always carry a map of the area I'm in and want to travel as well as my GPS. I'm certain all the users of this site are sincere and ernest in their efforts to be as accurate as possible. However I have found that sometime things don't always go as planned. Translation: who knows what happened? Go to the posted site and let them know and make any adustments you need to your GPS.

I want to thank you for letting me know and I will make sure to keep my eyes out for the signs before I turn.

Enjoy!

Many of the POI locations have had their coordinates located by geocoding of the addresses. Sometimes this can result in some errors depending upon how the streets show up in the goecoding database. It's, unfortunately, not an exact science. Errors are sometimes particularly present on new and also rural roads. And often "big box" stores like this create their own roads when the stores are built which adds to the error potential.

When you find errors, please record the correct information and send it on the file author/maintainer to help the community get better.

When dealing with chain location companies, I usually use one of the batch geocoding websites and that's where the errors are introduced. Even Google Maps does not have my house location correct.

These POI files are a "work in progress." The best thing you can do to help us and thereby help yourself is to report inaccuracies to the file author through the contact tab in their profile.

Be sure to provide them with the location's full street address and most important, the correct coordinates, if you can get them.

Like in this post:

http://www.poi-factory.com/node/19684

and this one:

http://www.poi-factory.com/node/16141

EDIT: MM beat me again! At least our two replies were consistant.

I am working on a file now with over 8000 locations. I am using GeePeeEx Editor which does a wonderful job. I try to check each location with the satellite view in Google Earth and on numerous occasions have seen that the location is way off. Sometimes miles. I then try to look up the location in Google or Yahoo and verify the correct location but even these can be off. Like MM said, it is not an exact science.

I will correct it...

Here is the answer to your Questionq:

A GPSr is a tool to help guide you, you still have to use your own head and a little common sense!

Now take the exact coordinates and report them to the keeper of the files, as you find the disappointments in the files!

Here is the answer to your question:

A GPSr is a tool to help guide you, you still have to use your head and a little common sense!
The members of this community create files for you and me as a service, usually Geocoding them as close as they can with out ever seeing the location, however now that you have the exact coordinates I suggest you report them to the keeper of the files.

Rather than being disappointed, become proactive, after all the files are free.

I have authored my fair share of POI files both for sharing here and for my own personal use. There have been countless times that I've located a POI by actually being there and using my GPS to determine LAT/LON. Subsequent entries in Google Earth places me in another location entirely. Lesson learned: Google Earth is generally not accurate with address information, particularly Street(with number), City, State and ZIP. I've been over 2 miles off in some locations. Google Earth is a good starting point for POI file creation, but there's nothing like being there in person for accuracy.

Absolutely agree!!

I've found mistakes in some POI files here already. And I just created a POI file over the weekend. I have been having trouble using www.itouchmap.com/latlong (which itself uses Google Maps). In several cases it tried to give me coordinates that were out of the state that I knew the POI was in. In a few cases Google/Itouch just couldn't find the location based on a government supplied address, even when I refined the data. In these cases I've temporarily added a comment that the coordinates are not accurate and put them in as closely as I could (usually at the community level). I'll go back and try to resolve these locations, but yes, there are a number of factors that can contribute to bad POI coordinates.

Google sometimes gives coordinates pretty far off when giving coordinates for an address on a street, people sometimes try to copy the coordinates manually and make mistakes, sometimes Google or other services return a completely different point on a search and the contributor needs to be vigilant to catch this. Sometimes the original data in the POI list is built from is either incomplete or inaccurate, and when that doesn't result in a failure to find coordinates it results in bad coordinates. And if someone has inaccurate or questionable coordinates they have to make a choice to either include them, knowing they could be inaccurate, or exclude them completely, which may cause someone to pass by a POI that they want and otherwise might find.

The POI files are a best effort. Hopefully contributors are trying very hard to get these point accurate. But like many things, they are dependent on information from many sources and subject to error, human and machine.

If you do find inaccurate points in the files please report them so that the data can be corrected and refined. One easy way to do this is to use your GPS to create a favorite where the POI actually is, and them when back at a computer give those coordinates as the proper coordinates for the POI that you found to be wrong.

Frovingslosh, question one and this is not bashing you. But are you a writer of some sorts or do you just like to write. I have noticed with every post you make there is a long story with it. Just curious nothing more I think you like to write.

I recently ran into the same issues with a POI I created of the NY State Wine region. I geocoded the winerys and then submitted the file to POI factory.

After I submitted the file I downloaded it to my Nuvi 260. It wasn't until then that I realized the coordinates were off. Several were located in Colorado. That's a l o n g way from the NY State Finger lakes. I have corrected the file and will resubmit soon.

The bottom line is like Reagan said: "Trust but Verify"

Regards
Tom

I downloaded some Las Vegas files before traveling last summer. My hotel in the downloaded file was way off. The GPS said go one way and my wife said go a different way. I thought maybe the GPS was taking me a shorter route. I was wrong, glad she had looked at a map.

When it did not take me to my hotel I lost confidence in the whole file and did not trust it anymore.

The built in file on the Garmin had me lost too. On the way back to the car rental center. I tried to follow the GPS. Las Vegas had moved the car rental center away from the airport. I had no idea how to get the car back. I drove around 15 min. Started thinking I would miss the plane. I finally got smart and found the address on the rental receipt and put that in. Then the GPS saved me!

I wish I would have saved my location when I picked up the car. Another lesson learned!

I just geocoded a file and saw the same thing happening. even though the data that I was passing included the zip code and I usually got the right state, several times the coordinates were way off what I expected and a zoom out confirmed that I was out of state.

I sure hope that I caught all of mine, but I do expect to do some polishing of the data at some point soon.

Suggestions:
Pay attention to the coordinates returned and watch for ones outside of the expected range.

Zoom out if n any doubt to see just where the locating site is trying to place you.

Be extra cautious on addresses prone to errors, My most common ones were highway numbers and "Main street".

Include the state in the search string if you can.