Paul Smith and I have had some intelligent discourse in the past and have both read numerous reports (e.g. TRL421 and TRL511, both of which show that risk of accidents increases with increasing speed on a given road). Paul's analysis is here: <http://www.safespeed.org.uk/trl421.html>.
Factoid:
For any car drivers out there, the speedo is the pointy needle thingy with the numbers round the outside - it usually has the odometer in the middle of it. If you are clever and match the numbers to the little black numbers in red circles you see by the side of the road, the little yellow boxes stop flashing as you pass |
Leaving aside the obvious misdirections (yes, Paul, we know that you could draw the line through the scatter plot to show that accidents decrease with increasing speed, but the TRL graphs reflect groups of similar roads, and it's not exactly surprising that roads with fewer hazards have higher speed limits), his main beef seems to be that there is no causal link established.
In short, according to Smith, the fact that the higher the speed on a given road, the greater the number of accidents, is either a bizarre coincidence or completely explicable by reference to some (unspecified) external causes.
TRL, on the other hand, choose to believe that nearly twenty years of research consistently yielding the same result - slower speed = fewer accidents - represents more than a coincidence; as the Slower Speeds Initiative point out: "The two main reasons why speed is such a danger are easy for most people to understand – at higher speeds there is less time to make adjustments for errors and the unexpected; and crash severity increases with speed." <http://www.slower-speeds.surf3.net/policybr3.pdf>. The causal link is there for all to see: ye canna' change the laws of physics.
 I am reluctant to leave the judgement of appropriate speed to the driver, for two excellent reasons: first, the driver is not impartial - any benefit from going faster accrues to them, and most of the danger accrues to others; and second, most drivers overestimate their skill 
Guy Chapman |
Now, the problem is this: Paul comes to these documents from a background premise that speeding is not inherently dangerous, but that speed enforcement is. I come to them from premise that speeding is dangerous for the reasons stated above and because other road users might be making judgements based on an assumption that you are not speeding, and of course because I as a cyclist would prefer the cars around me to be going slower; I think speed enforcement is good because the more cameras there are the more likely people will be to decide to obey the speed limit. This is obviously the triumph of hope over experience - what is more likely is that under the proposed changes to the Road Traffic Act they will get a slap on the wrist the first time, and any repeat offences will attract rapidly escalating penalties.
There have been many rambling arguments on the issue of speed, usually instigated by Paul cross-posting between uk.rec.cycling and uk.tosspot uk.transport. These arguments tend to shed more heat than light, and inevitably lead to one or more of the tired old cager whinges like "cyclists run red lights so have no right to complain about motorists breaking all the rest of the laws" and "cyclists pay no road tax and have no compulsory insurance, so can't complain about the carnage caused by cagers in their mobile death greenhouses" (I think I might have paraphrased there a bit) or "cyclists ride on the pavement so are responsible for untold carnage (i.e. somebody was killed by a bicycle once, although in that case it was the pedestrian's fault)." These are, of course, a smokescreen.
As both a cyclist and a driver who obeys speed limits, I have a vested interest in reducing the numbers of people who speed. I justify this self-interest on the grounds that it coincides with the interests of vulnerable road users and, of course, the law of the land.
Paul asked for a right of reply. He has, of course, no such right - this is my website after all - but we are reasonable people so here is his statement, with no cuts or amendments:  I agree that "speed" is one of the best ways to improve road safety from the present position forwards. There are many reasons to believe that there would be very few accidents if all vehicles were always going slowly enough to stop when necessary. You say "excess speed over the limit is the problem". I say "inappropriate speed for the conditions" is part of the problem. We can reduce inappropriate speed with improved driving standards, and especially with improved attitudes from drivers. My experience and research, (including most work by the TRL, with TRL511 and TRL421 being shameful exceptions) suggests that even quite severe schemes of speed enforcement will do little to reduce dangerous and inappropriate speeds. Despite a decade of mushrooming speed cameras we've had by far the poorest overall casualty reductions since the early 1950s, so the extraordinary claims from the so called "safety camera partnerships" must be ignored until we see something (anything!) appear in the national statistics. There's plenty of information and analysis on http://www.safespeed.org.uk where I make sincere attempts to find real ways of improving road safety. 
Paul Smith |
Actually Paul and I agree on many things. We agree that the real problem is poor driver skills, and that inappropriate speed is what is dangerous. We agree that fewer accidents would happen if everyone always drove within the distance they can see to be clear. We differ, though, in what constitutes "inappropriate speed for the conditions" - my definition of "inappropriate for the conditions" includes being in excess of the posted limit (Paul suggests that this is my sole criterion: this is not true; I have repeatedly said that in my view the safe speed is often much less than the limit, and never more). This is a view founded at least in part on my understanding of a little-known document, the Highway Code, or more accurately on the Road Traffic Regulation Act 1984, as described therein. I am also reluctant to leave the judgement of appropriate speed to the driver, for two excellent reasons: first, the driver is not impartial - any benefit from going faster accrues to them, and much of the danger accrues to others (such as pedestrians and cyclists); and second, 85% of drivers think they have above-average skills. This statistically improbable figure is just one of many indicating what repeated research tells us - most drivers overestimate their skill.
If you read Paul's statement at right, you may notice the following sentence: "Despite a decade of mushrooming speed cameras we've had by far the poorest overall casualty reductions since the early 1950s." Sounds bad, doesn't it? Now remove the emotive language. The result is: "Speed cameras have spread. Casualties have reduced." Against a background of steadily increasing traffic - an ever-increasing proportion of journeys is made by car - that sounds suspiciously like success. The whole anti-Gatso argument rests on the touching belief that reductions in accidents are purely coincidental, increases in accident rates as speed increases are purely coincidental, reductions in accident rates when speed decreases are coincidental, documented reductions in accidents at blackspots with cameras are coincidental. All can be explained by some combination of external factors which have nothing to do with the fact that people have slowed down.
You may also begin to see that I have an issue with organisations like the Association of British Drivers, who probably started the whole Holy War against speed enforcement. I have no sympathy, you see, for drivers who are caught by speed cameras. It's not as if it's a surprise that speed limits exist,after all. Cars are all fitted with speedometers these days (also indicator switches, although nobody seems to use those either). In fact my view is that the more cameras the better. Every camera is one less site where traffic officers might have to spend a wet Monday on a speed check. The traffic officers can then go and get on with spotting other kinds of dangerous driving - and until a camera is invented which can detect crass stupidity (a Twatso camera?) this job is best done by humans. Speed limits permit of automated enforcement, and the main beef of the driving lobby appears to be that they can no longer speed with impunity. My heart bleeds.
I have resolved that as of Jan 1 2003 I will not participate in any thread crossposted to uk.transport, unless it is on matters directly related to cycling. Ultimately the pro-speeding brigade are fighting a losing battle. The Government is against them (except during the run up to the next election, when pro-car policies will become the norm for a while), the TRL is widely respected and consistently finds against them, the Police are against them.
Ultimately, the speed limit is a legal maximum and that's an end of it.
|