How the IAF enables safety outcomes
The IAF assessment methodology enables programmes of safety projects to be included in the 2018-21 NLTP to deliver the step change in safety outcomes sought in the GPS by:
1 - Allowing for assessment and investment decisions to be made at a programme rather than individual project level:
- Currently packages of inter-related and inter-dependent activities submitted for funding consideration are able to include activities with BCR <1.0 provided the overall package demonstrates delivery of net positive benefits that exceed whole of life costs and all the components of the package are completed.
- The new policy enables the same approach as packages to be taken for programmes of work when the components of the programme are seeking to deliver a common outcome but they are not necessarily inter-related or inter-dependent.
- The policy also establishes the mechanism to allow inclusion of activities that are highly effective in achieving GPS priorities but have a BCR <1.0 into a programme, provided the overall programme demonstrates delivery of net positive benefits that exceed whole of life costs.
2 - Providing clarification of the ‘do nothing’ and ‘do minimum’ for economic appraisal of speed management activities.
In this situation, the ‘do minimum’ will be set at the safe and appropriate speed under the Speed Management Guide(external link). The ‘do nothing’ is the existing baseline conditions of the network, based on the existing speed limit and existing infrastructure and services and forms the basis for assessing the effects of a safe and appropriate speed limit in the ‘do minimum’. For some situations the best safety improvement option may be to simply lower the operating speed to a safe and appropriate level through the use of speed limit signs and minor infrastructure improvements that go with the new speed limits – this will be the do minimum option and can potentially be the preferred option to enable safety improvements.
3 - Travel time changes sensitivity testing
With respect to the treatment of travel time changes, the Transport Agency expects the evaluation of all activities and/or programmes to include the calculations of all positive and negative benefits. Where the travel time changes are neither significant nor relevant, it may be appropriate to provide sensitivity testing excluding travel time changes.
Guidance for the 2018-21 NLTP will be subject to change once the results are available from research that is planned during 2018/19 and to be implemented for the 2021-24 NLTP.
In all instances where any proposal (standalone project, or an activity within a programme) has a BCR <1.0, funding for these will only be approved by exception at the appropriate level of delegation.
For selecting the best safety investment option for a project, incremental economic cost-benefit appraisal continues to be required.