The Measured Mile is No Silver Bullet
The measured mile is routinely sold as the answer to disruption and loss of productivity claims.
The decision in Amey LG Ltd v Cumbria County Council 2016 EWHC 2856 (TCC) shows why that proposition does not withstand scrutiny.
The Court did not reject the measured mile. But it stripped it of the mystique that some experts trade on. What remains is a tool that only works when it is anchored to reality, causation and records.
Methodology does not replace proof
One of the clearest messages in the judgment is that a comparison exercise is not evidence of causation.
At paragraph [18.32], the judge described Amey’s productivity analysis as:
“simply an exercise of contrasting the planned achievable outputs and the actual output achieved, without investigating the reasons for the shortfall.”
That observation goes to the heart of the problem. The Court accepted that productivity changed. It refused to accept that the change was compensable without proof of why it occurred. Loss of productivity is not established by arithmetic. It is established by causation.
A measured mile must reflect reality, not convenience
The judgment is particularly sharp on the danger of convenient baselines.
Amey relied on planned outputs derived from tender assumptions rather than outputs actually achieved in comparable, undisrupted conditions. That approach was criticised directly. At [18.33], the Court recorded the competing position that the planned outputs:
“ought to have been taken from the productivity actually achieved where the disrupting event did not occur – what is referred to as the ‘measured mile’ approach”.
But the sting lies in what followed. The Court made clear that even a measured mile only works if it is verified. It:
“ought to have been verified by being able to demonstrate that the planned outputs had actually been achieved in some cases where the disrupting events did not occur”.
In other words, a measured mile is not asserted. It is proved.
Aggregation is where claims go to die
A recurring theme in the judgment is the Court’s resistance to global or averaged productivity claims.
At [18.32], the judge noted that Amey’s analysis:
“made clear that Amey was advancing a global claim, but without the necessary evidential underpinning”.
That is fatal language.
The Court was not persuaded because the analysis failed to disaggregate by activity or patch type, failed to distinguish different site conditions, and failed to separate alleged disruption from other causes of inefficiency. A measured mile that smooths reality into averages does not survive judicial scrutiny.
Productivity loss is not commercial disappointment
The judgment also exposes a familiar sleight of hand. Difficulty is repackaged as disruption. Commercial underperformance is rebranded as inefficiency.
The Court rejected that approach repeatedly. At [17.22], dealing with a related productivity argument, the judge concluded:
“the claim as advanced has not been made out, and there is no acceptable alternative claim which Amey could invite me to make based on a proper or acceptable analysis.”
That is not a criticism of method. It is a criticism of substance.
The Court was not prepared to compensate Amey for outcomes that could just as readily be explained by management decisions, resourcing choices or foreseeable working conditions.
What the judgment really says about the measured mile
Read properly, Amey v Cumbria gives clear guidance.
The measured mile:
is not a shortcut to causation,
is not proof of entitlement, and
is not a substitute for records.
It can assist where comparable undisrupted work actually exists, the comparison is genuinely like for like, and the analysis isolates the disruptive cause from all others. Absent that, it collapses.
The uncomfortable truth
The reason the measured mile is oversold is simple. It looks scientific. It produces numbers. It avoids uncomfortable questions about records, causation and contract risk.
This judgment calls that out.
Loss of productivity must be demonstrated, not inferred.
Methodology must explain reality, not overwrite it.
Experts who treat the measured mile as a silver bullet should read this case again.
At Accura Consulting, our team of experts work with clients to create a tailored solution to problems. If you have an issue and want expert support, get in touch.
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