Research on Full-Process Cost Management for Transport Infrastructure Construction Projects

Transport infrastructure projects are characterised by substantial investment scales, extended timelines, and multiple stakeholders. Cost overruns and deviations from investment objectives remain persistent global challenges. To enhance cost control and value realisation in transport infrastructure projects, this paper employs a combined approach of literature review and case study analysis. It systematically reviews domestic and international research progress on whole-process cost management and life-cycle cost (LCC), identifying key cost control mechanisms across project phases—decision-making, design, procurement, construction, final settlement, and operation/maintenance. Building upon this, a theoretical framework for whole-process cost management is established, integrating ‘vertical phases’ with ‘horizontal elements’. Further integrating practical experiences from high-speed railways, urban rail transit, and expressways, the paper summarises and explains the operational mechanisms of strategies such as constrained design, contract price limitations, change and claim control, dynamic cost monitoring, and information-based collaboration. Findings reveal existing limitations in full-process cost management, including weak phase transitions, insufficient incorporation of operational-phase costs, delayed responses to dynamic risks, and information silos. To address these shortcomings, this paper proposes a closed-loop control pathway integrating full life-cycle concepts. Theoretical innovations and management recommendations are presented across four dimensions: (1) early cost warning triggered by earned value and threshold mechanisms; (2) cross-phase cost information integration via BIM/data platforms; (3) design-procurement-construction (DPC) collaborative constraints driven by target costs; and (4) iterative estimation parameter refinement fuelled by operational data feedback. This paper's contribution lies in integrating LCC, risk early warning, and digital collaboration into a unified framework for whole-process cost management. It provides a generalisable theoretical reference for achieving ‘front-end pre-control – mid-process correction – back-end feedback’ cost governance in transport infrastructure projects.