BIM capability assessment for improving the efficiency of design in railway projects

The construction industry is increasingly adopting building information modelling (BIM) due to its benefits, including early collaboration, error reduction, and improved quality. This study systematically assesses BIM capabilities in the design processes of railway projects managed by Network Rail (NR), a national authority in the UK, and Gaziantep Metropolitan Municipality (GMM), a local authority in Turkey. Using a tailored BIM capability assessment tool, the study evaluates the performance of BIM attributes across architectural, structural, and building services design. The findings indicate that NR achieved Integrated BIM (Level 2) across all design disciplines driven by enhanced BIM uses such as code and compliance checking and phase and 4D planning. In contrast, GMM achieved Performed BIM (Level 1), particularly in structural design where BIM is applied selectively for tasks like design authoring and 3D coordination. The difference in scale leads to varying BIM implementations, with NR benefiting from a standardised approach supported by national-level mandates and resources. The study highlights that smaller authorities like GMM can improve BIM practices by adopting national-level strategies. Furthermore, organisations in countries with mandatory BIM requirements show more advanced BIM applications, such as integrating BIM with geographic information system for clash detection and improved coordination.