MacB said:
Pricing, with the No's of vehicles involved, I reckon unit cost, per vehicle, could be around the £150 mark. I would allocate £50 million for the transmitter rollout.
Tried and tested - the specific design isn't tested and I've not claimed it is. The seperate technologies are tested, a speed limiter can be set electronically, via button, in a car. Are you hanging your 'untested' bogeyman on the lack of ability to transmit that signal remotely? The in car setup could even have a dual mode so, in case of localised transmitter failure, it then sets speed based on GPS data it has stored. Or are you going to tell me this is a way out whacky untested idea as well?
Foreign vehicles - need the kit same as everyone else, we drive in France we need to buy a hi viz and red triangle and some spare bulbs(I haven't been for a while so it may be more/less now). Vehicles come here they need to buy an in car kit...simples.
Speed limit changes - have a think about how often this actually happens compared to how many speed signs you see.
People bypassing the technology - yep that'll happen, I don't think an unbreakable law is feasible.
It may be a poor idea but certainly not for the objections you put forward.
£150 is about half the value of my Mum's car (which is what I used to drive). £150 is over 2 days work for me. Now, with your normal motorist this alone is going to cause a lot of friction.
As for the £50m, that again is a very large sum of money which could be put to much better uses.
My problem with the technology is that, yes, individual elements do work and are around. But when you put them together in a project of this scale any failure is a major one.
As for having to get some hi viz and bulbs to go to France....total cost £3 at my local poundland. Completely different ball park to your scheme.
As for speed limit changes, I'm well aware that there are more signs to remind people than there are changes in speed, but there would still be a very large number of these transmitters. The amount of changes in speed limits doesn't overaly matter if you're saying it would cost £50m.
Like you say, it may be poor idea....so let's not waste £50m+ on it.
I'm sorry, but that doesn't address any of the issues I've listed, and in fact raises more.
What's by far the most simple, the cheapest, the safest and the easiest is for drivers to grow up, realise that a couple of miles of roadworks will add only a few minutes to their journey, and slow down for a bit.
Do the workmen change several miles of limit signs every time they knock on/off?
No need. Variable speed limits.
Do we have limit signs with the times alongside, because that brings more problems than it solves?
How does it? I was thinking more along the lines of electronic signs, which motorways already have.
Do we move all heavy plant away from the roadworks and set up temporary escape zones/hard shoulders every time the workmen down tools?
Errm....how does this make any difference to increasing the speed limit? I wasn't suggesting people drove through the road works.
Do we re-route the contraflows that take traffic onto the other carriageway twice a day?
Actually time the work so it is done efficiently so minimal disruption is caused. Point isn't really relevant to an increased speed limit. Certainly, through parts of unmanned road works keeping the lower speed may be necessary for a period of time.
Ultimately, I don't really have a whole lot of issue with this as it's not really a problem I encounter (other than maybe a couple times a year going back and forth from UNI). I might have more objections if I was commuting every day and my journey was 10 minutes longer, unnecessarily. My point was much more that if someone was driving through empty road works (safe) at 70mph, rather than say 50mph and got finned for it....I can see why they'd think it was a tax (or at least it's being sly). Especially if it looks like the road works are being intentionally delayed.
. I was at the front and worried that I wasn't going fast enough for the group .... whooops 
