Embracing the commercial benefits of adopting performance-based specification for road pavements
(09/07/2010)

For nearly 100 years, construction of roads across the world has used a standard method recipe approach, which specifies certain types and quantities of materials, without permitting deviations to improve sustainability, economics or road life.

In contrast, performance specification sets out ‘key performance indicators’ (KPIs) for the highway construction. Contracting engineers are required to demonstrate that the method and materials satisfy KPIs relating to foundation surface modulus, traffic induced deformation, whole life cost, design life and, naturally, the carbon footprint.

Tensar International has called for contractors to embrace the commercial benefits of adopting performance-based specification for road pavements. In a wide-ranging paper entitled ‘Plotting the road map for performance specifications’, Tensar highlights that the Highways Agency's Interim Advice Note gives contractors a unique opportunity to extract greater value from highways projects.

Co-authors of the Tensar paper, Cliff Hall and David Cashman, explain: “Performance specification, which is endorsed by the UK Highways Agency, requires that contractors make a step into the unknown. For this, they carry responsibility for success, but the payoff can be high for both parties. Contractors are able to use the most economic materials, which consequently reduces installation costs. Research in the United States also shows that lifecycle costs can be reduced by up to 10 percent when switching from method-based to performance specification.”

Performance specification is already acknowledged by highways authorities in the USA, England, Wales and the EU - based on research and actual in-road testing over 20 years. But, despite this, the industry has been slower to adopt than other parts of the world.

“Performance specification in highways construction encourages a contractual environment that stimulates innovation and obtains the best value results based on engineering experience and insight, rather than a formulaic approach. With clients focused on performance, best value solutions will drive forward economic and environmental advances”, the authors conclude.