Road widening for key transport links

The design works for this key project, involving taking a concept design through to detailed design, were fast-tracked to meet the clients’ accelerated programme for delivery.

The Nadi and Suva road upgrade project comprised significant road widening on the routes between Fiji’s international airports in Nadi and Suva and the adjacent towns and tourist destinations. The Nadi and Suva road upgrade is 6kms and 4kms in length respectively, and is being upgraded to a continuous length of four lane dual carriageways.

The design works, involving taking a concept design through to detailed design, were fast-tracked to target the appointment of a contractor and commencement of physical works as soon as possible to meet the clients’ accelerated programme for delivery. The fast-tracked project required agile management of the design process and Opus successfully enabled this through a collaborative approach with MWH and FRA, undertaking risk workshops early in the design, value engineering workshops after the draft detailed design was completed, and constructability reviews upon completion of the detailed design to reduce likelihood of issues arising during the tender and construction phases.

The Suva project is a rural route with a 60kph speed limit. In meeting the project travel time objective, the design speed was increased to 90kph which put significant constraints on the geometric alignment design in mitigating impacts on land-take and earthworks. Innovative approaches to safety in design have been introduced to Fiji through this project through use of clear zones within AustRoads guidance. 

Similarly recognition of the culture of Fiji and alternative modes of transport (walking and bus transport are pre-dominant modes in Fiji) have resulted in the provision of walking facilities along the route, to keep pedestrians off the carriageway and bus stops at key drop off locations that are known to be established along the route.

Opus has undertaken the design and project documentation and we have subsequently been invited to manage the construction procurement and supervision phases.

The works involved localised traffic modelling for signalised intersections, road geometric design, traffic engineering, stormwater design for both piped networks and open channel drainage, utility relocations / diversions, landscape architecture, street lighting design and structural design. The significant challenges for this project arose around the constraints of widening a road in an already built-up environment and required careful management of utility identification and relocation, meeting adjacent landowner expectations while ensuring continuity of accessibility along the route.

In Nadi, we have also introduced an early contractor involvement process into the construction phase, working with the client, contractor and utility services companies to manage significant additional utilities undergrounding and future proofing works which were added to the project just after the contractor commenced on site.

The deliverables included draft detailed design, final detailed design, and tender design. A draft detailed design report and final detailed design report were also provided at relevant stages along with updated bill of quantities, tender documents and specifications.