Off-site construction in highways projects: management, technical, and technology perspectives from the United Kingdom

With a rich off-site construction (OSC) experience accumulated over the last two centuries, the United Kingdom (UK) is looking up to OSC to deliver its critical infrastructure projects in the next decade. Highway projects are good fits for OSC with their project characteristics. However, the extant OSC literature for highways is mostly about OSC elements' design performance. Also, the OSC literature is predominantly building sector focused. Addressing this gap, the paper presents the findings of a research project, sponsored by the UK's National Highways, which aims at understanding what needs to be done to improve the current OSC condition for highways projects in the UK from a management, technical and technological perspective. After a detailed literature review, 20 in-depth interviews with subject experts were conducted. The initial findings were validated through five highways projects as cases and then ranked by two focus groups using the Delphi method. Alongside revealing the current OSC condition, 95 suggestions (43 management-related, 23 technical opportunities, and 29 technology-related) were elicited and ranked by their impact potential. Some of the high-potential suggestions are developing a collaborative OSC decision making framework, a product design mindset, improving OSC digital product libraries, creating mobile OSC factories, and a design options repository. The findings revealed that many OSC challenges identified in the general or building sector focused OSC discussions exist also in the highways sector. It is recommended that the identified high and medium impact potential suggestions are prioritized by practitioners and policy makers to improve the current OSC condition.