Request to improve your database

Just a few notes in response--I'm sure the actual admins can note more:

a) You should note that POI Factory's database is almost entirely crowd-sourced, and--at least in my experience--has tended to be better in North America (SCDB is fairly Euro-centric, POI Factory largely covers the US and Canada and SCDB would actually be expected to have better coverage in Europe). POI Factory also tends (in my experience) to be quicker at noting sudden changes in RL deployment patterns than SCDB (among other things: RL and speed cameras being removed in TX due to court order, some increases in NYC near school zones, etc.)

b) POI Factory's files are largely optimized for Garmin systems as well as TomTom and compatibles (including at least one major smartphone GPS program, CoPilot). Not all the options for different speedcam warnings are available without multiple files (and again, SCDB largely makes these available for various GPS tools that DO have warnings for distinct speeds, such as iGO--popular in Europe, but with a very low user base in the US compared to Garmin/TomTom/Magellan and compatibles).

In other words: Most of the userbase just wants advanced warning, and doesn't require files and tweaks for each specific speed (especially since in the US, you have a lot of combined RL/speed cameras). You also have areas with variable speed limits due to schools that compromise the majority of speed camera areas in North America, which also makes it next to impossible to note a specific speed.

c) Those sudden shifts you're talking about, like with the Boston speed camera? Those are almost to a one in school zones (another reason there's not a nicey-nicey "pick your speed" like SCDB)--a lot, in fact, most speed cameras in the US and Canada are in school zones where the normal speed limit may be 45mph/80kmh but drops drastically to 25mph/40kmh or even 15mph/20kmh when school opens for the day and closes for the day. (In general, variable speed limits around schools are almost entirely a US and Canada phenomenon; it's expected that a speedcam database based in Europe isn't going to catch this.)

d) Speed trap databases aren't done because--outside of a few jurisdictions that are notorious speed traps (like a certain town in Ohio that actually ended up being de-incorporated, among other things) speed traps are such a moving target in the US and Canada that no database can be expected to keep up with them even if it were updated daily. In my own area (a city and surrounding suburbs where the developed area is close to a million people) you will actually see police change enforcement points multiple times a day, and the frequency of enforcement also changes. Again, there are very few places that can RELIABLY be said to be speed traps most of the time (mostly in very small towns and along state borders where there is a large speed shift)--at least for I-95 (a major north-south highway in the US) there is an existing POI set for the known "regular" speed traps here.

And yes, police here in the US and Canada frequently change the location of "stakeout points" for speed traps multiple times a day by design; they don't want the equivalent of "shunpiking" (aka where speeders deliberately slow down or bypass the particular speed trap). About the only places that have permanent speed traps are, again, along borders of states with a SIGNIFICANT drop in speed (like the WV-MD border where the interstate speed limit formerly dropped from 70 to 55 with little warning) or in very rural small towns along an interstate or state highway (where there really isn't an alternate route) that gain practically all their income from speeding tickets.

Honestly, in the US and Canada your best bet for detecting speed traps involves a mix of contacting the local AAA (which usually keeps tracks of the worst "permanent" speed trap areas), keeping a radar detector (if you are in a state or province where it's legal--I'd argue if you're in Canada the radar detector won't help you as so many provinces ban them) with lidar and multiband detection, using an app like Waze in populated areas (Waze is usually pretty good at noting where police speed traps tend to be, even if it is crowdsourced it has a large enough userbase it's kept up to date), and using a CB radio tuned to channel 19 on rural highways (yes, the truckers will know where the speed traps are and will warn each other, and you may as well take advantage of the intel).

SCDB may have more quantity, but the quality is lacking in that they have some older RL and speed cameras that are not actually in use, and are also lacking some new ones that do show up in the POI Factory DB.

A good example is at https://www.scdb.info/en/countrycameralist/USA/34 where SCDB is still listing Dallas, TX RL and speed cameras; RL and speed cameras were actually ruled unconstitutional in Texas well over three months ago and the law was changed in Texas three months ago to ban RL and speed cameras in the state (http://www.poi-factory.com/node/49845). The existing cameras are in place up to end of contract but any citations from them are unenforceable legally.

I also saw some listings where it was noted the cameras were removed but still kept in the SCDB database, and I half suspect they're doing a fair amount of this "fluffing". (Again, keep in mind SCDB is a database subscription service based in Europe, paid in euro, based in Hamburg, Germany that probably doesn't have the resources to keep the non-European databases up as much as the Euro DBs--seriously, they don't even take into account variable speed limits at school crossings with speed cameras installed, which is pretty much purely a US/Canada phenomenon.)

How reliable would any static database be that has mobile speed traps, that change when ever the police cars move to another location.

If you absoulutely need that than rely on Waze so you don't get speeding tickets. Or just accept that if you speed you might get a ticket. Maybe obey the speed limit?

Thanks for all of your information. It's exactly what I do have
experience with both database. Just love the design of SCDB for
each speed trap. In fact, it's very hard to accept the ticket when you speed up at the wrong time, wrong place.
Just wanna to add that Waze can help you only in the big city,
like previous post, small town need speed ticket for their living, then it's very hard to avoid them. For example, in Carolina, police trap always take at least 2 cars for speed tickets, not one by one as others. Thanks again.

As a retired LEO, I have some suggestions for you. From some of your comments, it appears that you are trying to use a speed database as a way to avoid receiving a speeding citation. Listed below are a few ways to avoid a citation:
1. Most obvious; don't speed. That is the best way of avoiding a citation, but most people don't want to do this.
2. If you do speed, keep it to five miles above the limit on local and state highways; 9 miles or below on interstate highways. (Most officers will not issue a citation for speed violations at or below these points. There are too many people out there that will be speeding at a higher limit and the officers would rather cite them, then give a citation to someone speeding at a lower speed.) They may stop you at a lower limit, but most of the time, you will drive away with just a warning; unless you get mouthy with the officer, then, you are writing yourself a ticket. There have been many times when I have stopped someone to issue a warning and they started giving me a rough time. At that time, they actually wrote their own ticket. Give the officer some respect; there are just doing the job that they are paid to do.
3. Don't use a radar detector. In my particular state, on an interstate, you can get by driving 9 miles per hour over the speed limit. That is, unless you have a radar detector. At that point, you will probably receive a citation at 70 mph. The reason for that being that the officer thinks that if you have a radar detector, you are probably trying to avoid a ticket by using the detector to determine where the police have radar or laser setups. Most of the officers that I know, frown on that and will not give warnings and will write citations at a lower speed.
That is the end of my public safety message for today.

The last time I was stopped I was going 70 mph. I was on a work trip and was listening to an audio book on my old nuvi 760. I was surprised to be stopped as I was (I thought) only going 5 mph over the limit. I actually told the officer that I "usually speed and go 5 mph over the limit". As I was talking with the officer I switched the GPS back to the map screen, saw the 55 mph limit on the screen and said, "Oh! It's 55!" He said, "Oh, so that's why you thought you were only 5 mph over the limit."

I agreed that was the issue and told him flat out I had the cruise control set for 70. He said he was going to give me a ticket even though it was obviously an honest mistake and I agreed with him that I was deliberately going 70. He went to his car for a bit, came back, gave me back my license, and said, "It's 55 all the way to town" and let me go. I'm positive that, if I had been mouthy or tried to say I wasn't speeding or something like that I would have had a hefty ticket for going 15 mph over the limit.