Bridges

Transport for NSW is making the Western Distributor smarter and safer. The project involves implementing a Level 1A Smart Motorway operation on the Sydney Harbour Bridge, the Western Distributor, and the Anzac Bridge. A Level 1A Smart Motorway aims to provide variable speed and lane use management signs, enhanced wayfinding, incident detection, and other operational tools to offer a safer, more consistent, and less congested journey. The structural design work is undertaken by Stantec, as part of the overall design team led by the main consultant Aurecon. The construction is delivered by The Smart Link Alliance, which comprises Seymour Whyte, Ventia, and Transport for NSW.

The route is primarily elevated above ground level on concrete and steel viaduct structures. Smart Motorway ITS equipment includes roadside cabinets, Automatic Incident Detection (AID), Integrated Speed Lane Use Signs (ISLUS), Variable Message Signs (VMS), and CCTV cameras. Most of the equipment is supported by new steel gantry structures. A total of 19 large steel gantry structures are required for the project, either supported by the existing elevated viaduct structures or foundations in the ground.

This paper discusses the challenges and lessons learned from attaching new structures to the existing elevated viaduct structures, including site data collection, detection of existing reinforcement and post-tensioning ducts, and assessment of the existing structures; the design of the new gantry structures, especially the fatigue design; and design considerations to accommodate construction.