… In gentler times, one could walk up Downing Street and have someone take a snapshot of oneself outside Number 10 standing next to a Bobby wearing a shoulder cape and pointy helmet… I’ve got one somewhere in a shoe-box.
https://images.app.goo.gl/pST4d8tSVSy5KEJc8
Edited to say this is an old-style Avon and Somerset constable and the London Bobby had a shorter Cape IIRC.
Google Maps is constantly updating with speed limits - very useful. But do follow the signs.
I am so pleased that I used the Bip@Go device on our three week tour of France. We didn’t have to stop at all at the toll gates except for a couple of seconds waiting for the barrier to rise.
Karen - sorry if I’m being dense but what isn’t working?
Brian
Surprised you think it worth it for 3 weeks…We’ve never bothered as it is only very rarely that we use busy toll stations, so doesn’t seem worth the money to save a couple of minutes. Most times less than 30 secs difference.
Before we changed to LHD we just had a grabber stick if travelling alone.
So useful if it’s a priority for you, but for us it would just be another thing to have to remember,and subscribe to.
12 on the OP’s list was
My wife was sceptical initially, but with many toll stops on our trip she agreed it was well worth the small outlay. I enjoyed driving up to the barrier seeing it swing open.
How long do they take? I was struggling at first to navigate, and not miss any speed restrictions, this being my first time in France with satnavs playing up. The built in satnav showed no 30kph limits at all nor 90kph. It would give a zoomed in road view or a distant birds eye view seemingly at random.
I gave up completely with mine - utterly useless - and bought a cheap Tomtom which I use instead 
Others will know better than I do about how long they take to catch up with you…
if you go through a speed trap, the French can’t access your details to send you a ticket currently in the UK apparently. Was reported in the early months of this year that the agreement between UK and EU countries that had worked for this, had not been renewed. Apparently the EU countries were keen to reestablish the link for some reason. I haven;t heard of any progress on re-establishing it.
That’s interesting @KarenLot - I wonder if anyone had personal experience of it this year?
In answer to @MichaelL - I asked my friend who received two (!!!) speeding fines last year, and was told that they took about 5 weeks to come through to the UK on both occasions.
Even if a naughty vehicle can’t be pursued, later, in UK…
It might well be that folk will find themselves “stopped and sorted” during their visit in France, maybe even as they get set to leave the country… if their numberplate is noted and zapped through the French computer system… until wham…
I’ve no idea, but it’s surely possible… isn’t it ???
I would have thought so - and that wouldn’t need access to the DVLA for identification either (which I imagine is one of the blocks). Whether the authorities will bother is another matter 
Is it usual for fixed cameras in France to flash like in the UK?
A few do, I have seen them. Luckily mostly (but not quite always) flashing cars on the other side of the motorway.
But just like the UK, most don’t seem to flash at all now.
The only thing is to work on sticking to the speed limit at all times.
I’ll let you know. 
We did a 2500 mile road trip at the beginning of October, and in the first couple of days my beloved was ‘making conversation’ while I was trying to drive in pouring rain. The distraction of trying to hear her, work put what was required and provide an answer meant that I missed a change in speed limit from 110 to 90 (for just a couple of hundred meters, apparently without reason as noted in the OP) and got flashed. I also managed to collect a second flash in the Cantal while keeping up with local traffic. Entirely my own fault, that one. 
Driving in France is a very different experience to what it was in the 90s.
Speed limits are meant to be 10 kph lower in the rain, but speed cameras don’t do weather
Universally? Now I DIDN’T know that.
Before most speed cameras, there is usually a reminder of the speed limit - so if you ignore the reminder, you’ll get done…