Why are "grid line cameras" not in PocketGPS UK SC

CS · Lifetime Member Joined: Feb 29, 2004 Posts: 113

Why are the gridline camera detection lines not included in PocketGPS UK SC database? I can't remember what they are called but I'm sure it begins with a "T". Idon't know how they work but as you are about to pass one the telltale signs are these:

3 gridlines embedded across just half the road approx 8" apart

small concrete type post about 3 feet tall opposite gridlines on roadside with a flat surface facing towards gridlines

Does anyone have any information about these "camera detectors" if indeed that is what they are. There are plenty of them in York area. Exactly what are they and how do they work? If they are "safety cameras" should they be listed in the PocketGPS UK SC database??

DavidW · Posted: Fri Apr 30, 2004 8:08 am Post subject:

There are some temporary sites like this in mid Bedfordshire, near where I live - though I think they're all out of use now. There were permanent sensors in the road (which I think may be pneumatic), which fed into a bollard where the camera could be connected. It looked like a video camera on a lowish tripod.

These sites are only active if the camera is connected - and I think in those cases they're manned. They seem to be obsolete, at least around here - laser from the back of a van seems to be used instead.

The T you're thinking of is Truvelo - it looks a bit like a Gatso, but the support arm between the post and the camera is often painted blue. The sensor is inductive loops in the road rather than radar (though I believe there's now some inductively operated Gatsos). If a Truvelo site is missing, that's just because nobody has submitted it.

David

CS · Lifetime Member Joined: Feb 29, 2004 Posts: 113

Thanks to David for setting me straight. However the question remains should these sites be reported to the PocketGPS team?

Darren · Posted: Fri Apr 30, 2004 10:13 am Post subject:

As DavidW has said they are semi permanent installations where the induction loops are installed in the road surface and a small post nearby contains the hookup to which a Traffic Car plugs it's speed measuring equipment.

The problem with such sites is two fold, firstly we need to be sure that it is indeed a speed trap site rather than a traffic census installation and secondly when users receive alerts and see no cameras or traffic cars they report them to us as incorrect and it is then difficult for us to verify the true status of the site.

I am moving towards producing a seperate database for mobile installations, so that users know that it is a 'possible' danger zone and not necesarily always active, this will have a different icon using a Gatso on a Tripod. Hopefully this way we can reduce the false warnings.

I have provided the initial icon and database download at http://www.griffinnet.co.uk/downloads.htm which contains only three sites so far but feel free to use this as the basis. If anyone knows of such sites, regular haunts for traffic cars or safety partnership camera vans etc then provide me with the Lat/Lon and any information or your database .ov2 file and I'll start building up this database.

In a similar fashion I intend stripping out Red Light cameras to a seperate database when time allows!
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Darren Griffin

Tim Buxton · Posted: Fri Apr 30, 2004 10:33 am Post subject:

David,

DavidW · Posted: Fri Apr 30, 2004 1:24 pm Post subject:

A lot of the Truvelo installations in Bedfordshire are bidirectional - the camera can be swung from one side of the road to the other, and there's sensors on both sides of the road to support this type of operation.

Unlike a Gatso (which, on all the sites I've seen, use a visible light flash that would blind a driver), the IR flash allows a Truvelo to be forward facing, and the single direction Truvelos that I've seen are all forward facing.

They are indeed permanent installations.

David

matt_e · Posted: Fri Apr 30, 2004 7:43 pm Post subject:

I wish the speed cams POI only contained speed cams - the red light cameras are IMHO a pain. Firstly I would never consider jumping a red light. Secondly there are so many red light cameras in my area of London that the alarm is going off all the time. Grrr. Wink

Darren · Posted: Mon May 03, 2004 2:55 pm Post subject:

matt_e · Posted: Mon May 03, 2004 6:14 pm Post subject:

Sounds good Darren Thumbs Up

Matt

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