Preferred location of the new Nowra bridge
In July 2014, the NSW Minister for Roads and Freight announced planning for the new bridge should focus on a location as close as possible to the west (upstream) of the existing concrete bridge.
Site options development study
This announcement was based on the recommendations from the Nowra Bridge Project Site Options Development Report prepared by Roads and Maritime Services. This report outlines the process of determining and assessing various location options, the investigations carried out and the process used to determine the recommended location.
Investigations as part of the study started in 2012 and included:
- Asset condition assessment
- Traffic modelling
- Sensitive land use
- Preliminary environmental investigations
- Urban design and landscape character assessment
- Community consultation.
As a result of these investigations, Roads and Maritime identified five possible locations for a new river crossing:
- Option A – Western bypass option
- Option B – Immediately west of the existing crossing
- Option C – On the existing southbound bridge alignment
- Option D – Immediately east of the existing crossing
- Option E – Further east of the existing crossing.
These options were assessed as part of a value management process that looked at the project objectives and discussed the opportunities and constraints for each option. Participants then agreed on the most appropriate criteria for the options to be assessed and weighted them in order of perceived importance. Each option was then assessed and ranked in order of their perceived value for money.
By the end of the workshop, participants recommended Option B should be further developed as the preferred option. It was also recommended Roads and Maritime ensure the project considers options to address traffic concerns at the intersections at Bolong Road, Illaroo Road and Bridge Road.
The Site Options Development Report recommends a new bridge should be built as close as possible to the west of the existing bridges (Option B). This recommendation was based on:
- Technical input from recent and previous studies and investigations
- Feedback from the community at various stages throughout the project
- Recommendations of the value management process.
This Site Options Development Report is available on the project documents page.
Investigations carried out as part of the site options development study
Asset condition and assessment
An assessment of the condition of the iron truss bridge was carried out to look at current and future maintenance needs.
To look at the potential impacts on Aboriginal and non-Aboriginal heritage sites. Further investigations and consultation with the Nowra Local Aboriginal Land Council will be necessary to ensure any Aboriginal heritage issues are fully appreciated. Several non-Aboriginal heritage sites have been identified which include the iron ‘Whipple’ truss bridge.
To look at local and through traffic patterns in the Nowra Bomaderry area. This involved origin destination surveys to assess the proportions of vehicles that are travelling through Nowra Bomaderry, in or out of Nowra Bomaderry, or entirely within Nowra Bomaderry. Traffic modelling also looked at congestion issues around the current Princes Highway and will form the basis of more detailed modelling as the project progresses.
To look at the ease of construction of a bridge at the locations around the current highway. This took into consideration the practicality of various construction methods in the constrained space available, the depth of the riverbed and the risk of driving piles near the existing bridges, the extent of utilities in the area and the ability to complete construction activities while allowing traffic to continue flowing.
Sensitive Land Use
To look at the number and types of land use in the study area and to identify any parcels of land that may be impacted in terms of future land use.
Preliminary Environmental Investigations
To look at the potential environmental constraints in the study area. This was carried out in the form of a high level desktop analysis for all of the options and a further walk through of the study area around the existing highway.
Urban Design and Landscape Character
To look at the visual and social impacts of any new infrastructure in the study area, including the need for pedestrian and cycling connectivity. Urban design will continue to be an important consideration as the project progresses.
Community and stakeholder consultation
Consultation was carried out prior to and after the value management process. See community involvement page for more information.
Value management is a process used by Roads and Maritime to bring together technical experts and key project stakeholders to make recommendations and develop a way forward for large infrastructure projects.
For the Nowra Bridge project, a value management workshop was held on Thursday 22 May 2014 to help the project team assess five different locations against agreed criteria.
Option B was recommended at the workshop with downstream (Option D) to be further developed as a contingency in the event that a design solution for Option B cannot be achieved.
Details on the workshop, including information on how options were assessed, are available in the Value management report.