Unfortunately speed limits do save lives. We all know the difference between hitting someone at 30 and hitting them at 45. However hidden speed cameras, and excessively draconian speed limits have no place on the road. In the UK whilst most people speed a little, most of us that 'get caught out' are often doing a safe speed on good road, in good conditions which has a stupid speed limit. Where i live several main roads have recently seen the spped limits dropped from 40 to 30, 60 to 50 and even 70 to 40! the rational behind this being a number of recent fatalities. What the powers that be forget to take into consideration, is that these accidents were (in this case) caused by large groups of teenagers crammed like sardines into poorly maintained dangerous cars being driven at excessive speed. It makes no difference to these people if the posted speed limit is 40 or 60 they're still going to drive along it at 70 to 80 at 2am in the morning, and they're still going to crash and kil people. Lowering the speed limit (in these cases) only serves to annoy good drivers and generate the government more revenue when we accidentally get picked off by a mobile speed trap on road that we trully didn't realise was 40mph, because the road is built to the same standards as a motorway. I'm sure you can tell what happened to me.

I must tend to agree with the previous comments on vastly increased and enforced speed limits.
Over the past 50 years I have driven almost every type of car, and many motor cycles, capable of vastly exceeding the limits of the time - without being penalized.
However in the last five years or so I have been "caught on camera" and subsequently fined for speeds that were only a few MPH above the limit including one occasion on a deserted motorway in the early hours of the morning when I drove at 45 mph through equally deserted roadworks.
In essence the reasoning that limits are being imposed to save lives is flawed. In fact no such limits, or cameras, are instigated until TWO people have been killed on a given stretch of road - surely a single death is too many so why wait?
More worrying is the huge numbers of speed traps being introduced and the latest technology of "traffic management" or "variable speed limits". Both these innovations allow authorities to change speed limits at will in order to feed the cash generating cameras.
In more remote areas new and underhand signage is being employed. I recently entered a village before which [quite fairly] the speed limit was reduced from the national limit[60mph] in stages to 50, 40, and the 30. However on leaving the village the next sign [within a 100 yards of the 30MPH derestriction] was a 50 sign - inducing drivers to up their speed. However just around a blind bend, less than 500 yards away, there was another 30mph sign - making it almost impossible for drivers to reduce speed in time - and thus open to prosecution. Surely it would have been more sensible [ but not cash generating] to simply extend the 30mph limit through the entire stretch of road.
If authorities were really trying to reduce traffic speeds they would employ more automatic speed indicating signs and not employ cameras or use valuable police resources.
If drivers are to be confronted by 40mph limits on deserted main roads and motorways their respect for sensibly imposed speed limits is going to be reduced with inevitable results.
If you care to motor in Northern Ireland you will find few cameras and even less people exceeding the limits - there must surely be a moral there!