HyD employed us for this Assignment to conduct a comprehensive review of the current 1) “Guidelines on Design of Noise Barriers” jointly published by EPD and HyD (The Guidelines), 2) “Structures Design Manual for Highways and Railways” (The Manual) and 3) “Practice Notes No. BSTR/PN/003 – Noise Barriers with Transparent Panels” (The Practice Notes) published by HyD shall have to be reviewed. This Assignment also includes the study of innovative ideas in the aspects of cost-effectiveness, acoustic design, aesthetic design, structural forms, different top shapes, active noise control devices, noise barrier materials/design which will allow air to pass through and hence reduce wind loads while offering effective transmission loss for road traffic noise, absorptive materials re-generated from waste and any special features to enhance the acoustic effectiveness as well as the examination and recommendations of feasible innovative options for Hong Kong.