Bring back the red flag?

It's Wednesday. On Wednesdays I go shopping, and that involves driving down a certain local road. This road dates back to the 1920s or 30s, when the availability of land was not a problem, so it's a good wide road - indeed four lanes wide for part of its length. The houses which line it were built around the same time, and are set well back from the road with long front gardens. When I first started driving, and roads were either 30mph or derestricted, this road was derestricted. Then, when variable speed limits came in - 1960s or thereabouts - it became a 50mph road. About 20 years ago, it suddenly was redesignated as 40mph, and then a few years back, reduced again to 30mph. This in itself is baffling - nothing has changed except the volume of traffic. The road is as it ever was, no new houses have been built, so on what basis this has been done is a mystery. What really gets up my nose, however, are the new speed limit signs. "Speed limits life" they proclaim under the new 30 figure. It's not just the sanctimonious and patronising tone that gets me, it's the fact that the statement is at best misleading, and at worst a deliberate untruth. There is no evidence that an increase in speed, in and of itself, makes the likelihood of having an accident more likely - indeed up to a point, quite the reverse. All evidence shows that the safest speed (that is the speed with the lowest accident rate associated with it) is around or just above the "85th percentile" speed - that is the speed which, left to their own devices, 85% of drivers would not exceed, and in most cases this is well in excess of the posted speed limit. It's bad driving that causes accidents (and inappropriate speed may well be a factor), but unfortunately the police have long since given up on policing driving standards, and speed cameras bring in a nice little revenue for no effort. Once again, I have no axe to grind - I have no points on my licence, although that's as much a matter of luck as anything.