Proform Civil was contracted to produce the geometric design, stormwater drainage, civil construction documents and construction estimate of a three way roundabout over an existing tee intersection. The roundabout design was to accommodate congestion issues and provide safe free flowing traffic manoeuvres to suit right of way vehicles from all legs. The project is a part of the City of Greater Geraldton's "Utakarra Road Network Upgrade Project" or URNUP.
The project presented challenges with limited available land along with a network of underground and overhead services. The design had to incorporate future road network reconfigurations and eliminate unnecessary redundant road pavement.
The project is a current Proform Civil project and is been processed in conjunction with surrounding staged URNUP intersection design's. A part of the project brief was to design the roundabout with minimal land resumptions and service modifications. Proform Civil utilised advanced methods in 12D civil software to tweak the roundabout geometry and obtain the optimum balance between obvious cost savings associated with property/utility modifications and addressing the needs and safety of all road user's which come with a roundabout in this environment.
Due to the location and environment, pre-deflection was designed on the roundabout entrances. Pre-deflection not only slows vehicles to a safe and comfortable approach speed but also creates an awareness of the required driver attention after the long straight and open legs of road network which surround this particular intersection.
Proform Civil liaised with Western Power and other service authorities to negotiate utility relocation options and costs. The outcome was a feasible design for the roundabout which balanced the amenities of the intersection and the expense of relocating existing services.
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