Road Design Standards Research and Development - Safety and Capacity Review

National Highways is seeking research partners to review and modernise key road design standards (DMRB CD127, CD109, and CD116) affecting the strategic road network. This programme will investigate whether motorways and major roads can safely accommodate additional lanes beyond current limits, and evaluate alternative road configurations (such as 2+1 or 2+2 layouts with central barriers) that could match performance at lower cost. The research will also assess the continued appropriateness of design rules for speed and visibility, including design speed methodology for rural roads and object detectability standards that impact collision risk. Additionally, the work will examine large, complex junction designs (such as major roundabouts) to identify and address any gaps in current standards that could cause operational or safety issues. This research is urgent because existing standards may unnecessarily limit network capacity, increase project costs, or create unintended safety risks. Updated standards could enable more efficient, safer, and more cost-effective road schemes. Suppliers should have expertise in road design engineering, traffic safety analysis, and knowledge of DMRB standards and highway engineering practices.