Criticality screen

Find the assets that have to be looked at separately, and see what a likelihood times consequence ranking does to that list.

The seamThe criticality register built by multiplying two scores, and the rare severe asset that finishes at the bottom of it because it hardly ever fails.

The World Road Association's manual says critical assets have a high consequence of failure but not necessarily a high likelihood of failure, and should be identified separately. On the same page it says risk is likelihood multiplied by consequence. Both are right, and they answer different questions.

Practice merges them. A criticality register gets built by scoring both, multiplying, and sorting the column. Do that and the estuarial crossing that fails once a century ranks below the drainage gully that blocks twice a year. The asset the first sentence exists to protect drops off the bottom of the list. This page runs both and shows you the difference.

There is no total here and there will not be one. Why a weighted score hides the argument rather than making it.

Screen at a consequence of

On any single dimension. The threshold is a judgement too, so it is a control rather than a constant hidden in the code.

The ratings below are ours and are illustrative. The asset types are the manual's own examples. Change anything you disagree with: the finding does not depend on these numbers, only on one asset being rare and severe.

Asset	Safety	Service reduction or failure	Environmental	Financial	Reputation	Contractual	Likelihood
Estuarial crossingA major structure with no practicable diversion. Decades between failures, and no way round when there is one.	Estuarial crossing, Safety	Estuarial crossing, Service reduction or failure	Estuarial crossing, Environmental	Estuarial crossing, Financial	Estuarial crossing, Reputation	Estuarial crossing, Contractual	Estuarial crossing, likelihood
Tunnel ventilationLoss of ventilation closes the tunnel and can harm people inside it before it is closed.	Tunnel ventilation, Safety	Tunnel ventilation, Service reduction or failure	Tunnel ventilation, Environmental	Tunnel ventilation, Financial	Tunnel ventilation, Reputation	Tunnel ventilation, Contractual	Tunnel ventilation, likelihood
Single track access to a third party substationThe road is minor and the asset at the end of it is somebody else. Blocking it takes out supply the authority does not own.	Single track access to a third party substation, Safety	Single track access to a third party substation, Service reduction or failure	Single track access to a third party substation, Environmental	Single track access to a third party substation, Financial	Single track access to a third party substation, Reputation	Single track access to a third party substation, Contractual	Single track access to a third party substation, likelihood
Higher trafficked road, resurfacing dueHeavily used, deteriorating on schedule, and diversions exist.	Higher trafficked road, resurfacing due, Safety	Higher trafficked road, resurfacing due, Service reduction or failure	Higher trafficked road, resurfacing due, Environmental	Higher trafficked road, resurfacing due, Financial	Higher trafficked road, resurfacing due, Reputation	Higher trafficked road, resurfacing due, Contractual	Higher trafficked road, resurfacing due, likelihood
Lower trafficked road, same conditionThe same deterioration on a road that carries a fraction of the traffic.	Lower trafficked road, same condition, Safety	Lower trafficked road, same condition, Service reduction or failure	Lower trafficked road, same condition, Environmental	Lower trafficked road, same condition, Financial	Lower trafficked road, same condition, Reputation	Lower trafficked road, same condition, Contractual	Lower trafficked road, same condition, likelihood
Roadside drainage gullyBlocks predictably and often. Cheap to clear, disruptive when it is not cleared.	Roadside drainage gully, Safety	Roadside drainage gully, Service reduction or failure	Roadside drainage gully, Environmental	Roadside drainage gully, Financial	Roadside drainage gully, Reputation	Roadside drainage gully, Contractual	Roadside drainage gully, likelihood
Street lighting column, one of manyOne column out changes very little. Included so the set is not made entirely of things that matter.	Street lighting column, one of many, Safety	Street lighting column, one of many, Service reduction or failure	Street lighting column, one of many, Environmental	Street lighting column, one of many, Financial	Street lighting column, one of many, Reputation	Street lighting column, one of many, Contractual	Street lighting column, one of many, likelihood
Variable message signsFailure is visible to the public and removes a control the operator relies on in an incident.	Variable message signs, Safety	Variable message signs, Service reduction or failure	Variable message signs, Environmental	Variable message signs, Financial	Variable message signs, Reputation	Variable message signs, Contractual	Variable message signs, likelihood

Safety: If this fails without warning, can anybody be hurt? Service reduction or failure: Who loses the service, how many of them, and for how long? Environmental: Does failure discharge, contaminate or breach a consent? Financial: What does the failure cost, including the cost of failing rather than replacing? Reputation: Would this failure be reported, and by whom? Contractual: Does failure trigger a deduction, a breach or a claim?

Criticality screen

2026-10-01. projects-advisors.com/tools/criticality

5 of 8 assets are severe on at least one consequence at a threshold of 3, so they are the ones to look at separately. Ranking the same list by likelihood multiplied by consequence, and giving that ranking the same 5 places, would have missed 1: Estuarial crossing. That is the cost of merging two questions the manual keeps apart. Computed in the browser at projects-advisors.com/tools/criticality

Asset	Worst consequence	Screened	Product rank
Higher trafficked road, resurfacing due	3, service reduction or failure	yes	1 of 8
Variable message signs	3, reputation	yes	2 of 8
Tunnel ventilation	4, safety	yes	3 of 8
Single track access to a third party substation	4, service reduction or failure	yes	4 of 8
Roadside drainage gully	2, service reduction or failure	no	5 of 8
Lower trafficked road, same condition	2, safety	no	6 of 8
Street lighting column, one of many	2, safety	no	7 of 8
Estuarial crossing	4, safety	yes	8 of 8, missed by the product

The screen takes the worst single consequence, never an average. An asset that can hurt somebody is not averaged down by being cheap to fix, and consequences in different units do not trade against each other. Likelihood is recorded and is deliberately not used by the screen, because the manual says a critical asset need not be a likely one. It is used only to build the comparison ranking, which exists to be argued with.

Computed from

PIARC Asset Management Manual, 2.3.3, identifying critical assets (PIARC manual, current online edition; read 2026-09-04)https://road-asset.piarc.org/en/data-and-modeling-risk/identifying-critical-assets
ISO 55001:2024, asset management system requirements (2024 edition; read 2026-09-26)https://www.iso.org/standard/83054.html