Speed Camera Coordinates Inaccurate

 

I am new to adding the speed camera POI's to my Garmin 650 and quickly noticed that the ones that I pass regularly are not very accurate. What I mean is that when putting the coordinates into Google Maps it puts it in the middle of the freeway and/or a noticable distance from the actual camera. I have gone in and adjusted the ones I KNOW where they are and got the added benefit of not getting a warning in both directions when the camera is only shooting in one direction. I'm guessing that's due to me moving the camera off the road, where it actually is.

Anyway, on to my question. Does anybody know why the coordinates are placed where they are and is there a website that shows a photo of the true location of the cameras? I have a bit of spare time at work and would like to fix all of the ones that are near me in the Phoenix area.

phxflyboy

.

First, the coordinates do not necessarily reflect the actual physical location of a camera or a building. You should think of it as a reference point from which the gps will give the desired alert(s). For instance, red light cameras might be located at 8 or more locations around an intersection, but a single POI in the center of the intersection will give alerts on both streets, in both directions. I can't speak to the decision to place the coordinates of the freeway cameras in the "middle of the freeway," since I don't know the specifics of that location. I am also not sure whether Miss POI makes any attempt to limit alerts on enforcement cameras to a single direction, because it is not supported by Garmin for user-created POIs. POI files sold by Garmin DO support single direction alerts, but they don't provide us with those tools.

--
Nuvi 660 -- and not upgrading it or maps until Garmin fixes long-standing bugs/problems, and get maps to where they are much more current, AND corrected on a more timely basis when advised of mistakes.

I understand the

I understand the intersection camera coordinates being placed in the middle of the intersection for exactly the reason you stated. I'm more concerned with the photo radar ones on the freeways. As far as the directional indicator, I think by moving them to their correct exact location, i.e. on the right side shoulder (for most cameras) for some reason it limits the alert to only the direction you are driving.

No big deal, I'm just going through and fixing them. If Miss POI wants my corrected files, I'll gladly send them. Or if she doesn't object, anyone who wants the file can have it. I just don't want to violate any site rules by sending it out.

phxflyboy

Hi

I put them in the middle of the road so that you will get alerts if you are in a lane that is far from the shoulder of the freeway.

We are highlighting the area that the camera covers, not the camera location itself.

Miss POI

Directional Alerts

I am now getting good alerts on the freeway cameras in the Phoenix areas that I drive. Earlier, I had some issues with directional alerts but now that is not an issue. Something must have changed. Thanks.
The roads I refer to are I10 and the 101 Loop.
Chuck

.

Thanks, Mary Ann, for the explanation. I at first thought Phxflyboy was saying that the coordinates for a N/S freeway were in the area between the north and southbound roadways -- the area showing as a median on the GPS when you zoom in, even though there is typically no median. I now see that we are talking about the placement in the middle of a north bound roadway only. A post by Phil Hornby has me questioning whether Phxflyboy might have a good point.

If I understood what I was viewing, Phil showed a screen capture of what the GPS sees for a roadway. It consolidates all the lanes of a roadway onto a single line of straight segments (that don't necessarily center all that well on a roadway. Likewise, the GPS, when it snaps a vehicle to the nearest roadway heading in the proper direction, would put the vehicle on that same line. So, as long as the POI was with the magic (50?)ft of that line, it would apply to all cars on that roadway, regardless of their specific lane, since the GPS snaps them all to the same line.

However, placement in the middle of the roadway may position the POI within that magic distance of the line for the other side of the roadway as well, and create an unnecessary alert for them. Perhaps we can have reliable directional alerts on any roadway that is shown as a divided highway by placing the POI to the side of the roadway so that it is within range of only the northbound line. For areas where we have few cameras, a rare false alert is no big deal, but where they abound (can you say Phoenix?), I could see the unnecessary and false doubling of alerts as being a real annoyance. Perhaps if Phil is still stopping by, he might comment on my understanding of what he presented. I know a few people like H Hannah have worked a bit on directional alerts and might also have some info re the reliability of such alerts ON FREEWAYS SHOWN as DIVIDED ROADWAYS.

--
Nuvi 660 -- and not upgrading it or maps until Garmin fixes long-standing bugs/problems, and get maps to where they are much more current, AND corrected on a more timely basis when advised of mistakes.

?

chaspoi wrote:

I am now getting good alerts on the freeway cameras in the Phoenix areas that I drive. Earlier, I had some issues with directional alerts but now that is not an issue. Something must have changed. Thanks.
The roads I refer to are I10 and the 101 Loop.
Chuck

Looking at some of those locations, it would appear they might be separated roadways so that a POI in the center of one roadway might well be outside the 50 ft range of the other direction and NOT alert. Could that be the case?

--
Nuvi 660 -- and not upgrading it or maps until Garmin fixes long-standing bugs/problems, and get maps to where they are much more current, AND corrected on a more timely basis when advised of mistakes.

miss poi, I understand this

miss poi,

I understand this logic of putting them in the middle for the reason you stated, however, the issue I have is that you then get a lot of false alerts when traveling in the opposite direction, where there is no camera. I'm simply trying to eliminate the false hits.

Also, it seems that the North/South East/West alignment is off, by quite a bit on some cameras. What I mean here is that if you are, say, approaching a camera while East bound on the I-10, the listed position for the camera can be as much as several hundred feet too far East, thus giving you the warning later than it should.

I know it sounds like all I'm doing is complaining, which I guess I am. However, I am VERY grateful for the work that has been put into these files. I'm simply making some observations and suggestions for improvements. I am "fixing" the files with the exact locations for my own use, probably due to my anal-retentive nature. Also I have the means to view the exact location of the cameras, making it easier to pinpoint them for the coordinates. If anyone wants my "corrected" file, just let me know by email or pm.

And again, thanks to everyone for the work they have done on these files.

phxflyboy

.

phxflyboy wrote:

If anyone wants my "corrected" file, just let me know by email or pm.

Phx,
Thank you for the offer, but unless Miss Poi adopts your changes, one would have to make these changes every time he downloaded Miss Poi's updates, which can be weekly.

Edit: Having now tested your file on my 660, I can confirm that I get false alerts in the opposite direction with the current file (with a simulation) and your technique eliminates it. This is true for divided roadways. Hopefully, Miss Poi will adopt this technique.

--
Nuvi 660 -- and not upgrading it or maps until Garmin fixes long-standing bugs/problems, and get maps to where they are much more current, AND corrected on a more timely basis when advised of mistakes.

False alert

Like on I17 north bound/bethany home rd. I get alert but theres no camera. The camera is on the south bound.

Unfortunately

gpnoy wrote:

Like on I17 north bound/bethany home rd. I get alert but there's no camera. The camera is on the south bound.

Unfortunately we (GPS Users) don't have option for direction for our POI's. Every time we approach a dot (our POI) on a map and are crossing set distance we get warning. You could be driving on Bethany Home Rd. and still got warning for the camera that is on the I-17. That's our reality.

I thought they were ripping

I thought they were ripping out all those cameras as tehy weren't approved