Peer review of the cost estimates for options to the south of Berry complete
An analysis of costs for southern bypass routes, completed in June/July 2008, has confirmed a route to the south of Berry is not feasible when compared to the other short-listed options.
The cost information was compiled by the RTA and Maunsell AECOM, following a recommendation made by an independent peer review undertaken in April/May 2008.
The independent peer review concluded that the Gerringong to Bomaderry route options selection process was well founded and consistent with good practice. However, the review recommended more detailed cost estimates of the routes to the south of Berry be undertaken to confirm whether these routes were feasible when considered as part of an overall option from Gerringong to Bomaderry.
The more detailed cost estimates have confirmed that a route to the south of Berry is not cost effective, even when considered as part of an overall option. For this reason, a route south of Berry will not be considered further.
The table below shows the cost comparison results.
In summary, when combined with the Brown route, the southern Berry bypass routes are between 1.2 and 1.5 times more expensive than the entire Brown route and they perform no better than the worst performing short-listed route combination (Yellow and Blue).^
ROUTE
LEVEL 2 ESTIMATE
LEVEL 3 ESTIMATE
Estimate ratios relative to the Brown route for provisionally short listed options and southern Berry bypass options
Estimates and ratios relative to the Brown route for final short listed options and southern Berry bypass options
Ratio
Ratio
$ million
Brown and outer Berry southern bypass
1.4*
1.5*
647*
Brown and inner Berry southern bypass
1.3*
1.3*
544*
Yellow and Blue**
1.2
1.3
545
Green and Modified Orange***
1
1.1
495
Brown
1
1
435
This level of estimate is appropriate when verifying the feasibility and affordability of routes at the preliminary concept design stage as reported in the Route Options Development Report Appendix A.
Based on broad assessment of quantities.
contains no contingency or planning and development cost.
Most current estimate.
Based on more refined preliminary concept design.
Considers refined design, quantities and probabilistic assessment of risk and contingency.
Contains planning and development costs.
* Cost estimates for the inner and outer southern bypass routes have been determined consistent with the preparation of estimates used for the review of provisionally short listed options (ie Level 2 estimates). Indicative more refined cost estimates for the inner and outer southern bypass routes have been based on routes with similar attributes and features consistent with the approach used to develop estimates for option comparisons (ie Level 3 estimates).
** Worst performing and highest cost combination from Sections B and C – considering functional, environmental, socio-economic and value for money performance.
*** Best performing combination from Sections B and C – considering functional, environmental, socio-economic and value for money performance.
^ Correction – The media release advising southern route cost analysis results, issued on 4 July 2008, contained an error in ratio figures. The ratio figures presented here are accurate.
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