James was the Senior Civil Engineer for the design of the upgrade works on the Gateway Motorway between Bicentennial Road and the Deagon Deviation.
Together with increasing traffic capacity and road user safety by widening the existing Gateway Motorway from 4 to 6 lanes, encouraging active transport with new and upgraded pathways were key drivers for the project. A 3.5m wide off-road shared pedestrian and bicycle riding path was designed (and constructed) along the length of the project, with connections to existing local bicycle and pedestrian networks. In total, over 15km of new and upgraded pathway was required, including connections to the existing Jim Soorley Bikeway at Nudgee and the Gateway Motorway pedestrian/cyclist underpass at Bracken Ridge.
James led the design of the shared path by coordinating and developing details included in the general civil (alignment & geometry), road furniture and signs and lines packages for the North project area.
Determining the most appropriate alignment of the new shared path was challenging. A design speed of 50km/h for cyclists was required and informed the path width (3.5m plus 1.0m minimum offset to obstructions), cross fall (2.5%) and maximum vertical grades no greater than 5% for accessibility.
To achieve the criteria, James led the analysis of two alignment options: online vs offline. The online option followed the geometry of the northbound carriageway, separated by a concrete barrier or landscaping if constraints allowed. Investigations into the offline option identified extensive upgrade works to the existing path network, including new bridge structures, to meet the design criteria.
Ultimately, the online solution was adopted as the alignment provided greater connectivity to existing local paths, improved pedestrian and cyclist safety through passive surveillance from road users and minimised impact to sensitive environmental areas including Boondall Wetlands and Cabbage Tree Creek.
The adopted alignment also provides safe and efficient maintenance access to critical Intelligent Transport Systems (ITS) infrastructure and electrical equipment along the corridor. Enabling a safer work environment for maintenance personnel by protecting them from live traffic and avoiding the need for costly traffic control. Access can also be attained during normal working hours, eliminating the need for night work and more time at home with family and loved ones.
A key element of the project’s design was to enable pedestrian/bicycle rider connectivity along the full length of the project. This is achieved via new or upgraded underpasses, accesses and separated pathways on bridge structures, including:
- under Nudgee Road and over the Gateway Motorway at Nudgee
- over Nundah Creek at Nudgee
- over Sandgate Road and the Shorncliffe rail line at Deagon
- under the Deagon Deviation at Sandgate
- under Depot Road (by BCC).
Image provided by Rix Ryan Photography.
