Does The Flap Of A Butterfly's Wing in Brazil Cause Traffic Chaos in Shrewton?

I suppose I should apologise to Edward Lorenz, American mathematician, meteorologist and pioneer of chaos theory who, in 1961 published a ground-breaking paper with the somewhat esoteric title of "Deterministic Nonperiodic Flow."  If you are a) a mathematician, b) a meteorologist, or c) an insomniac, by all means read it.  Otherwise, read about it.

Basically, Lorenz's paper and Chaos Theory suggest that a small variation of the starting conditions at one point in a system can have a profound affect somewhere else.  He later reported: "One meteorologist remarked that if the theory were correct, one flap of a seagull's wings could change the course of weather forever."  Seagulls clearly aren't very attractive and 11 years later, the seagull had transformed into a butterfly - and chaos theory never looked back.

So why am I wittering on about all this?  Well, to show how little changes can have huge and, allegedly, unanticipated impacts elsewhere.  After the closure of the A344, Shrewton has seen an increase in traffic on the A360 and other roads into and out of the village; a problem, a nisance, but not life threatening.

A beat of the butterfly's wing in Brazil back at the end of December may well have resulted in a shift in the Jet Stream and the torrential downpours we have experienced ever since.  That in turn has led to a rise in the water table at Tilshead of over 20 metres since December;  not surprising then that the Shrewton to Tilshead road flooded and Wiltshire Council installed traffic lights to allow vehicles to pass safely through the floodwater.  A nuisance, a bit inconvenient, but not life threatening.

On Friday, a half-term weekend when holiday traffic was anticipated on the roads - not to mention those folks heading to Somerset, Deveon and Cornwall to check on flooded properties - there was a minor shunt west of Winterbourne Stoke.  The A303 westbound diversion sign was uncovered at Longbarrow Roundabout and poor motorists conned by a mixture of Highways Agency and Wiltshire Council ineptitude into "following the triangles" - a none-existent diversionary route that takes vehicles off the A303 and then abandons them.  Annoying to all involved, a delay, a right royal pain in the behind, but not life threatening.

But his is what happened on Friday last:

An ambulance on a blue-light run is stuck in heavy traffic in Shrewton - not trivial, not just annoying, but a potential life threatening situation.

Of course, fingers could be pointed at an unknown and unidentifiable butterfly flitting about in a Brazilian rain forest for all these events.  But how much more likely is it that at least some of them were precipitated by another small and completely avoidable event:  the decision to close the A344 without improving the A303 first.

Had the A303 been dualled, there may not have been a crash, the diversion need not have been instituted and the traffic lights, which had worked fine for several days previously, might not have been overwhelmed by the sheer volume of traffic trying to avoid the A303 and the ambulance on a blue light run, need not have been impeded.  A life need not have been put in jeopardy.

This also takes us back to Adam Smith, the 18th century Scottish philosopher, who came up with the concept of the law of unintended consequences - as popularised by the American social scientist, Robert K. Merton in his 1936 paper entitled: The Unanticipated Consequences of Purposive Social Action." (A little easier to read than Lorenz's paper).

 This examines the unforseen consequences of intentional human interventions.  So whilst the muppets who pressed for, agreed to and allowed the A344 to be closed before the A303 was dualled and those who had fought against dualling the A303 for years to protect Stonehenge might argue that a threat to life was an unforseen consequence of their actions, that claim would bear a little more scrutiny.

The impact of the closure of the A344 without dualling the A303 were widely predicted many years ago. The impact of not dualling the A303 were also predicted years ago. Westbound crashes on the A303 to the west of Winterbourne Stoke on Friday evenings are commonplace.  Diverting traffic off the A303 as a consequence of crashes is also commonplace. Heavy rain happens, very heavy rain and groundwater flooding happens rarely; but it does happen.  Ambulances on blue-light runs drive through Shrewton on the A360.  There is a real probability, however remote a probability that might be,  that all these events will align in time and space as they did last Friday.  This shows the difference between hard science (Lorenz) and softer social sciences (Merton).  Lorenz would have looked at probabilities and chaos theory, whilst followers of Merton fail to anticipate.  Hard science deals in rare, high impact events.  Soft science waffles a bit

So, an ambulance stuck in trafficin Shrewton last Friday is, perhaps, a consequence of a metaphorical butterfly flapping its wings in Brazil and all-too real butterfly brains in the UK not thinking about the predictable consequences of their decision.  Profound or what?