Resumen
Design-build contracts with performance-based specifications are believed to raise productivity and the innovation rate. Such specifications for highway and bridge contracts may create risks, be too detailed or difficult to verify. The purpose has been to analyse how performance-based requirements are used in Swedish design-build contracts for highway projects. How contractors are encouraged to provide innovative technologies is emphasized. Generic documents from the Swedish Transport Administration for design-build contracts have been studied, and case studies of six design-build contracts with performance-based requirements have been made. Technical specifications for these contracts have been analysed and interviews held with both client and contractor project managers. Results include that it is along the time axis that major obstacles to innovation arise. Before the contractor is able to develop innovative solutions, the initial design plan restricts the highway geometry. During construction, a mix of performance and prescriptive requirement formulations is more of a challenge than clashes between performance requirements. The client may avoid performance language, more so for bridges than road surfaces, because of concerns with efficient maintenance in the future. It is recommended that performance-based specifications should be less detailed and that a life cycle view of highway projects should support innovative technologies.