In November 2005, the UK Department for Transport (DfT) produced an estimate of the cost of converting road traffic signs for speed and distance measurements to metric units. Optimism bias accounted for between 26% and 33% of the total overall cost. Now, the usefulness of optimism bias is being questioned.
The comments by John Frewen-Lord and The Glob following the last article on Metric Views reinforce the view that the UK’s imperial road traffic signs are a handicap, both for road users and for the country as a whole. Yet, for almost forty years, the change to metric signs has fallen in the political ‘too difficult’ box – too difficult to explain to the public, and too difficult to carry out without running a risk of losing popularity (and votes).
“Too difficult” is not a phrase that comes easy to politicians, and the DfT has been required to find alternative reasons for lack of progress with the sign changeover. For many years, the DfT claimed that it would be “confusing” to make the change while a significant number of drivers had received no metric education at school (Hansard, 2002). More recently however, the cost of the changeover has become the focus of its attention, and an estimate was prepared in November 2005 by the Traffic Management Division. This is available on the DfT web site: #mce_temp_url#
At about that time, the Treasury had introduced optimism bias to counter criticisms of the cost escalation of road schemes. It ranged from 45% for a standard scheme to 65% for a non-standard scheme, adding between £175 million to £254 million to the 2005 estimated cost of the sign changeover.
Recently it has become clear that UK costs of civil engineering projects exceed those of similar schemes in continental Europe by a substantial margin, and the Treasury-sponsored body Infrastructure UK (IUK) has been asked to investigate and report.
Its Chairman, James Stewart, said last week that this work had identified a fundamental need to change the attitudes of those procuring and delivering projects. The process where budgets are inflated to allow for things going wrong was flawed.
“For every public sector project, before you even start you add a 50% optimism bias to allow for contingencies,” he said. “That then creates an affordability envelope, and then you get a budget equal to that affordability envelope.
“So it is no great surprise that most projects come in to that price.”
Thank you, Mr Stewart, for casting doubt on that 2005 estimate – UKMA has always said it was far too high.
Stewart said a better model was the London 2012 Olympics, where the contingency fund is managed separately. The Olympic Delivery Authority chairman and former chief executive of Network Rail, John Armitt, agreed.
“Optimism bias is a fundamental failing,” he said. “We did it at Network Rail and all it does is convince people that the money is there to be spent.”
That said, we should not fall into the trap of becoming obsessed with cost. The real issue is political will. The national interest requires a single system of measurement which is understood and used by everyone for all purposes. On the highways, it requires consistent information in a single system of units used by all those involved. This includes pedestrians, motorists, motor manufacturers, those who build and maintain the network, the emergency services, map makers, and so on, as exemplified by the comments of John and The Glob.
Other Commonwealth countries and, closer to home, the Republic of Ireland showed that where there is a will there is a way. Now it is our turn.
(Some information for this article was taken from ‘New Civil Engineer’ of 4 November 2010.)