The Guangzhou Metro Design Institute (GMDI) is responsible for providing design verification of the seismic design of structures and tunnels of the Hong Kong Highways Department (HyD) and the MTR Corporation Limited (MTRCL) in compliance with the relevant design standards, codes, guidelines, manuals, etc.; and reviewing and providing professional advice on the design documents provided by the MTRCL in terms of seismic and geotechnical design in terms of economy and constructability and making recommendations for optimisation.