The objective of this paper is to demonstrate the potential benefit of using site- and project-specific pipe-soil interaction (PSI) inputs in HTHP pipeline design. The paper first explains the overall approach used to generate site-specific PSI inputs to pipelines. This includes showing the importance of site investigation (geophysics, in situ testing and sampling) and onshore lab testing which should be integrated to select appropriate seabed parameter ranges for the derivation of site-specific PSI inputs. Then, the importance of using geotechnical calculation methods which consider the unique properties of carbonate soils to calculate pipeline friction factors is discussed. Finally, the paper demonstrates, for a regional case study, how the provided PSI inputs changed pipeline design and reduced project costs.