Roads and Traffic Aurhority
Adam Hillard – Design
Mark Raven – Estimation
The Central Coast Highway is a major road link between the M1 Pacific Motorway and Gosford, Erina and the coastal suburbs. RMS engaged SKM to develop the concept design to transform the current two staggered T-junctions on the Central Coast Highway, to an at-grade four-leg signalised intersection at Brisbane Water Drive and Manns Road.
Running in parallel to the at-grade design development, Hillard Civil (now CCHD) undertook an investigation into alternative grade separated options (GSO). Several overpass and viaduct layouts were investigated and documented with a preferred strategic design option being established and progressed into the concept design phase. This option was issued for traffic modelling, cost estimation and presented to the RMS Major Project Review Committee. Although the GSO performed better under future traffic projections, the additional expenditure required was deemed unviable and the at-grade option was advanced through detail design and construction.
Key features of the preferred grade separated option included:
- Central Coast Highway (H30) east/west flyover (major traffic movement) via 45m long bridge Span (over realigned Manns Rd) resulting in a fully free flow arrangement
- Realign Manns Road and Brisbane Water Drive to an at-grade four-leg TCS T-junction
- Brisbane Water Drive eastbound traffic (second major traffic movement) connecting to Central Coast Highway under east/west flyover and via G-Loop.
- Geometric Road Design (Strategic & Concept)
- Strategic Bridge Design
- Volumetric Analysis.
- Property Impact/acquisition diagram
- Construction Staging (heavily trafficked environment)