© 2006-2008 Tom Donaldson.
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In our travels we used a GPS navigation system built into our truck. To get GPS coordinates, we entered the address into the navigation unit, and the GPS system did what is known as "geocoding" (converting an address into GPS coordinates). We also got coordinates by entering addresses into Google Maps, Google Earth, Yahoo Maps, and other online resources.
We noticed something rather odd. The resulting GPS coordinates were often incorrect, sometimes wildly incorrect. Sometimes incorrect by one or two states.
Worse, different sources sometimes agreed with each other and were still wrong. All of the data apparently comes from the same government agencies at various levels of government. Some folks "add value" to the data by fixing it up, but none of the location information is 100% reliable (not even on Continuous Traveler).
Sometimes we discovered how incorrect coordinates were the "hard way", which can be very hard when driving a large RV rig. Being a geek, I ended up spending a lot of time cross-checking location information and building a database of location information with GPS coordinates. Not just with GPS coordinates: I added quality ratings (a.k.a., confidence ratings).
You will notice that Continuous Traveler uses GPS coordinates heavily. What is unusual about Continuous Traveler is that it has a quality rating for each set of GPS coordinates. You can tell at a glance whether the coordinates are a guess, or are based on actually seeing the location on satellite imagery, or best of all, whether the coordinates were collected on the ground at the location.
The process of verifying, or attempting to verify, GPS coordinates is very time consuming. As a result, the number of RV parks on this site grows very slowly. About ten RV parks are added per day, and a few more are updated daily.
RV park information pages include GPS coordinates, plus some indication of how trustworthy the GPS coordinates might be. The GPS quality ratings provide a degree of "honesty" about GPS coordinates. Sometimes GPS coordinates are probably very accurate; but sometimes we know that they are probably incorrect. We tell you in either case.
Under the GPS heading you will see the subheadings Quality and Basis. For this park the Quality is Verified, meaning that there is high confidence that the coordinates are very close to the actual location of the park. The Basis of the verification is Feet On Ground GPS, which means that someone either got or verified the coordinates using a GPS navigation device while in the park.
If you are using Maps, you may actually be able to see the RV park. Zoom in all the way using the zoom "ladder" on the left side of the map. Then turn on aerial imagery by clicking the Hybrid button on the upper right of the map. You may have to zoom out two steps (Google does not have the highest resolution images for this area). You will see that the icon is approximately on the entrance to the park. When possible, this is how RV park icons should be positioned.
The Quality and Basis information indicates how much additional checking you need to do regarding the position of the park. In many cases you can verify the location for yourself by turning on aerial imagery (which may also show unadvertised surprises around the park).
For this park the Quality is Unknown, meaning that we cannot determine where the park is, really. The RV park's website does not give a street address, and their map is not detailed enough. A couple of RV park lists on the web say that the street address is "1 Frost St.", so we include that information, but there is no way to verify this using the aerial imagery discussed below.
When the RV park was added to the database an email message was sent to the park's email address letting them know that we listed them and that we could not locate them; no reponse yet.
Someday we may call the RV park to verify their location, but for now we just list the park so that you will at least know that it exists in this town; but we are also honest about the fact that we do not really know where the park is.
As of 8:00 PST, Saturday, 23 January, 2010, these are the counts of RV parks with verified and unverified GPS coordinates out of a total of 6110 RV parks:
So: over 95% of the GPS coordinates have been verified by at least cross checking multiple sources. Less than 5% have unverified GPS coordinates. How do other sites that show GPS coordinates for RV parks compare?
In validating the location of RV parks we rely heavily on satellite imagery provided by online map services. No one map service can "do it all".
ContinuousTraveler.com uses Google Maps on web pages. Sometimes Google Maps does not have the best resolution or most up to date images for a particular region. Often we use multiple sources to "see" an RV park.
Because these services use different image sources in some cases, each can have different resolutions and ages of images. Also useful: images on different services might be taken in different seasons. This can be helpful, for example, in a heavily wooded area if at least one source has a winter shot (no leaves on the trees to hide roads).
As noted above, the process of verifying the location of parks (or attempting to do so) is time consuming. On average I have added ten parks per day since the fall of 2008, and updated the listings for a few more each day.
I started with the parks that we had collected as a natural part of our travels. In the fall of 2008 I overhauled the web site and started forcing myself to add ten parks per day. I say "forcing myself" because this is very frustrating work!
I initially focused on parks in "destination" areas, such as the coasts. I'm now filling in the center of the USA. I expect to have picked all the low-hanging fruit (i.e., private RV parks with web sites) by spring of 2010. Then I'll focus on fleshing out listings of government parks (only have a few hundred at the moment).
And the really fun part: parks come and go; join/quit franchises; and parks change hands. The online maps and satellite images change frequently, usually for the better. Thus, I must constantly update listings.
As I add RV parks I check the GPS quality of listings for parks near the ones I am adding. If they are less than "Verified: Satellite Imagery", I recheck them. This is where most updates come from at the moment. I have noticed that for locations for which online mappers had really bad satellite imagery, the images are likely to have improved after one or two years. This is the source of most improvements in GPS quality.
If you are a park owner, you can help by checking your listing on this site, and telling me if it is wrong. If you are an RV'er, please tell me if your favorite parks are not shown in the correct location. And, of course, let me know if there is a park you want me to add.
The process is slow, but the goal is worthwhile: to publish some of the best GPS coordinates on the web for RV parks, and to honestly say when the GPS coordinates are probably not so good. One of these days Kay and I will be fulltimers again. I want a tool that we can trust when we resume our travels!