Being able to predict failure patterns of street assets may significantly reduce the cost of maintenance
If you manage public assets, some feel that you are fundamentally responsible for providing a service to citizens around the street scene, which itself partially defines the society in which they live. Your professional life may revolve around the maintenance of a sub set of street scene assets and belonging to a professional organisation may be an important part of how you acquire the knowledge that helps you to optimise effective maintenance within the available funds.
Someone in your team is publicly accountable and will have to provide feedback to stakeholders in the “Value Chain” and best practice may indicate a change in maintenance practice. Have we already seen one or two examples of such changes and are we about to witness others?
In the pursuit of providing a principle road network, Inspectors walked along the road and pavements noting down road defects. Where a road was defective over a wide area, treatments were recommended and, if the budget was available, work carried out. Then came the high speed survey machines and a new approach to the science of Pavement Management based on more data, much more data. Instead of acting mainly reactively, Highways Managers started to try to predict when a road would fail, having noticed that sums needed to bring roads back to their design standard suddenly increased (below a certain level of deterioration) with time.
The sequence of activities associated with this style of maintenance is judged by the industry to be lower cost and might be applicable in other Street Scene situations. The sequence is:
1. Inventory Definition
2. Pavement Inspection
3. Condition Assessment
4. Condition Prediction
5. Condition Analysis
6. Work Planning
UKPMS is kept up to date by the industry for the industry
Agreed algorithms to predict deterioration of roads are used by all Government Agencies in the UK that are the Custodians of Public Roads and the practice is common throughout the world with tailored algorithms to suits the political and physical climate in each region.
Can this principle be applied to other street scene assets or services? Would it provide a better return on our long term public spend or provide better services at a lower cost (the battle cry of UK Government today). Did it, indeed, provide an improvement over the previous position before UKPMS and, if so, how and why?
High speed machines travel at 60mph along pre-defined routes Roads (1) and collect data (2) which is processed and fed into software (3) which records Condition Assessments as set out in the UKPMS “code of practice” and time/date stamps them. Software is then used with the agreed algorithms to predict how the condition of the road will change over time (4) so that an analysis (5) of the overall road network condition can be made in preparation to be tested against available funds in order to proposed optimised treatments ahead of work planning (6).
The pre-requisites of 1-6 are that there is a standard way of doing each step and that enough reliable data has been collected over the years to enable robust predictions to be made, whilst data about the cost of treatment options is kept current for stages 5 and 6 particularly. It is also likely that the optimised treatment dependent upon available funds will show a shortfall, indicating the need for a further condition prediction cycle where the eventual deterioration of the road will render is unusable….leading in turn to a cycle of seeking additional funds to eventually minimise the spend on maintenance over the long term. This may be incompatible with short term Political aims, of course.
So, if we are happy that this method might be transferable to other public assets/public services, we need to ask the question “has the underlying science been done and enough data been collected?” An example is Street Lighting, where the cost of Lamp replacement to a 30m high column on a busy road junction is very high and to smaller ones is still relatively high. To this date, most Custodians of this invaluable public asset have used “Bulk Lamp change” as the most cost effective way of ensuring that our streets are lit to an appropriate level. The 2009 Street Lighting Engineer’s annual conference had quite a few papers presented on topics around “remote sensors”, some proposing that a revolution in cost reduction might be available through their use. Street Lighting Engineers also have to accurately report the energy usage to the energy supplier in the UK, according to an industry standard and these devices might be able to remotely control and vary the level of light, thus reducing the energy usage and provide a realistic “Return On Investment” (ROI) based on this characteristic alone. If they can also predict when a light is about to fail, does this mean that the cost of Lamp replacement will reduce? Bulk Lamp change was introduced for a reason and maybe there is not enough data around today to make that judgement.
I guess it might be appropriate to go through the 6 stage that defines PMS to see if one is happy with the ROI figures provided by the purveyors of the devices and software surrounding this science – and that it for Lighting Engineers to measure and “report back”. Time will tell.
What about Bridges? That is being done and we expect an update from the scientists collecting and examining the data via the County Surveyor Society (CSS) in April 2010.
Theatrical Street Scene at night in Belgium - saving taxpayers money?
How about our Parks, Green assets and sports areas? What about the Public Trees? And what about the Bins our refuse and recyclables are collected from?
Looking at the 8 types of Maintenance from last week’s post, I wonder what outsourced companies might agree with the Municipal Organisations of tomorrow and how the cost of public services will change with time. Will we create revolutions to reduce public spending or will we provide better and safer streets, where, perhaps, criminals are caught as they walk by Street Lamp Columns with retina scanners mounted at a vandal-proof height?
Will the street lights be dimmed at 9pm and raised at 11pm to signal that it is time to go home, as in a theatre – it is already happening in Belgium!
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