As a consequence of urban sprawl, the once sleepy town of Kiama’s major access road, the Princes Highway, is receiving an estimated $179 billion upgrade. The Reinforced Earth Company’s involvement included the design and supply of a geometrically unique TechSpan® tunnel, compliant with SM1600 bridge loading, to accommodate a freight train clearance envelope, 2400m² of architecturally finished TerraClass® concrete retaining wall and 1270m² of temporary ‘wire’ retaining wall. The three dimensionally curved tunnel required a 3D finite element analysis that modeled the asymmetrical fill loading impacting upon the arch during construction. With traffic to be diverted over the stage one construction in February 2005, stage 2 construction will begin in March 2005.