4.4.3 Whole-of-life Costs
The selection of the best sprayed seal alternative is also influenced by the availability of equipment, materials and expertise as well as the whole-of-life costs.
Whole-of-life-cycle cost analysis (Austroads 2009c) is an economic procedure used by asset managers to compare competing investment options over a certain analysis period and to identify the option that results in the minimum total life-cycle cost (i.e. the optimal option).
To undertake a whole-of-life comparison it is necessary to have an understanding of the performance of the various treatments, their expected lifespan and the intended next treatment. With this information, it will be possible to evaluate the initial construction cost in the context of which treatment will provide the best value for the road agency. This approach must of course be balanced with the need to minimise disruption to road users and provide amenity to adjacent properties.
Figure 4.2 illustrates the general relationship between initial costs and effectiveness for alternative sprayed seal treatments.
The use of a specialised binder (e.g. PMB, multigrade) will increase the price, which must be considered in relation to its effectiveness in the particular application.