Satbir Gill – speaker at ICE's upcoming Asset Management Conference and Network Manager at Hounslow Highways – tells us about the advantages of the London Borough of Hounslow's PFI approach.IntroductionFor a number of years, local highways authorities have been encouraged to develop Highways Infrastructure Asset Management Plans (HIAMPs), and the benefits of such an approach are widely acknowledged.Recent changes to funding arrangements mean that authorities now have to demonstrate that they not only have a HIAMP in place, but that an asset management approach is in operation and delivering benefits.Hounslow's ApproachThe London Borough of Hounslow's highways pathfinder PFI contract commenced on 1 January 2013Following a rigorous procurement process to secure funding and grant, the London Borough of Hounslow's highways pathfinder PFI contract commenced on 1 January 2013. The project includes the upgrade of 259 miles of carriageway, 458 miles of footway, street lights, signs, street furniture, trees, structures, drainage and street cleansing.The whole project was founded on highways asset management principals, which was instrumental in it securing government approval.The main features of the PFI model are:Financing comes from capital borrowing, supported by the government, and is released to the PFI contractor in monthly unitary charge payments – conditional on the contractor meeting the required performance standardsContractual performance targets cover both operational aspects and infrastructure condition. This includes a requirement to improve highway infrastructure assets to a specified "steady state" condition during the first five years of the contract and to maintain that condition for the remainder of the 25 year contractWhile unlikely that there will be any new highways maintenance PFI projects over the coming years, the current plan has been running for three years. This presents an opportunity to assess whether the projected asset management-related benefits are being realised, and to consider lessons learned to date.Benefits of the Highways PFI ModelThe highways PFI model has a number of advantages over the conventional local authority funding model:Certainty of funding over 25 yearsOpportunity for innovationEconomies of scaleContractual service level standardsCommercial incentives to minimise whole life costAs with any HIAMP implementation there is a need for high quality data and supporting models to ensure that contractual performance measures can be calculated, reported, audited and achieved. There is also a need to certify that the contractor is able to plan future interventions to reduce cost over the life of the project, and a need to minimise the risk of performance failures.Ringway and Jean Lefebvre have developed their own sophisticated Asset Optioneering Model (AOM), which can calculate whole life costs of various road construction and rehabilitation options over the network. This helps minimise costs, carbon emissions and energy consumption, while maximising performance, durability and recycling of construction waste.Progress and Achievements to DateAs of July 2015 Hounslow's PFI contract has delivered the following:571 carriageway schemes and 435 footway schemesAround 14,000 new street lights resulting in 40% energy savings68.8% improvement in overall road and footway condition – ahead of the contract improvement profileAll signs and road markings replaced with long-life solutionsCompleted upgrade of two out of the five bridges needing improvementCompletion of five Special Engineering Designation SchemesReduction in the level of defect reports and accident claimsImproved street cleansing performance and Local Environmental Quality survey scoresLessons Learned and Transferrable FeaturesWhile many local authorities faced with implementing a HIAMP regime may not have the luxury of the levels of funding and long-term consistency that highways maintenance PFIs enjoy, there are a number of lessons that can be applied from projects such Hounslow's:It is important to be explicit about the level of performance that can be expected and afforded, with all parties signing up to measures. There should be clear, published criteria on the standardsThere are considerable benefits to taking a long term, technical and commercial viewA capital injection to build life into the network represents the lowest whole life cost solution, and can be justified by a clear business caseThe advantages of predictability of longer-term funding (so that if the best value solution is to delay treatment for a number of years, funding will still be available) allow decisions to be made on maintenance options based on optimal timing and minimum lifecycle cost rather than availability of fundingSatbir Gill speaks at ICE's Asset Management Conference on 10 November 2015. Our conference provides a platform for engineers, asset owners and operators to discuss, exchange views and come to conclusions on what is most important for the future of UK's transport and infrastructure assets.Visit the conference homepage to see the full programme and book your place.