This thesis concerns the identification of critical aspects involved in the successful procurement of privately financed tolled transportation infrastructure projects in the UK. The aims of the research are: • To identify through a triangulated research methodology those factors considered as of critical importance to the successful procurement of privately financed tolled transportation infrastructure projects in the UK. • To establish a ranked order and weighting applicable to factors identified. • To determine whether specific factors identified as critical can be classified as either Failure Reduction Criteria (FRCs) or Critical Success Factors (CSFs). The findings indicate that in practice there are certain factors that are more important in achieving success and/or reducing the likelihood of failure in the procurement of privately financed tolled transportation infrastructure in the UK. Furthermore, a distinction between FRCs and CSFs has been established from participants involved in this style of procurement, and the research identifies fourteen FRCs and four CSFs involved in this style of proeurement. The triangulated approach to the research has lead to significant confidence in identifying factors of importance as they have been identified from three independent data sources. Factors have also been ranked. The findings of this research may offer valuable information to both public and private organisations in their pursuit to successfully procure privately financed projects.