Question - Roads

1. Can the Minister advise the most commonly used resurfacing treatment mixtures on ACT Government roads. 
2. Does the resurfacing mixture ever vary at all (different compositions, cold or hot, of coarse aggregate, bitumen, sand etc).
3. How are roads determined to be suitable for certain treatments.
4. Are types of treatments/ mixtures applied at the aggregate level, such as the suburb level, or are they tailored for individual streets.
5. Can the Minister outline the factors that are considered in the implementation of these mixtures (costs, durability, whole of life costs, environmental concerns).
6. Is the resulting friction noise (due to tyres) considered in the type of resurfacing treatments used. 
7. Will the Government prioritise reducing friction noise in future management of its road resurfacing program.
    

(1) Spray Seal is the most common type of resurfacing treatment used in ACT. This provides an economical method to ensure that the road surface is watertight and so protects the subsurface road structure. Other resurfacing treatments include asphalt overlay and micro-surfacing.

(2) Each of the above-mentioned treatments are designed specific to the use case and mix aggregate size, additives and the number of layers applied is engineered to suit the load case for the specific road section. The design of the surface treatment (and materials used) can also vary between suppliers who often have proprietary mix formulations.

(3) There is a rigorous, highly technical system in place for collection of road condition data, analysing the data and selecting a certain treatment for a particular road. While selecting appropriate resurfacing treatments, careful consideration is given to the historical methodology used for the original road construction and the current overall condition of the road. Road hierarchy, road geometry, traffic volume also plays important role in preparing the annual road resurfacing program.

(4) Suitability of each treatment is assessed against individual road and specific location within the road. 

(5) As outlined in (3).

(6) Yes.

(7) Different resurfacing treatment types create different levels of noise. Typically spray seal surface treatments create a higher level of noise shortly after treatment with the level of noise reducing over time as the tone embeds within the bitumen matrix. The noise generation characteristics of surfacing treatments are considered for resurfacing schemes along with the noise sensitivity of adjacent land uses.