Council looks after Island roads in two main ways: by responding to urgent issues such as potholes, and by planning larger road renewal works. Safety-related defects are prioritised first, particularly after inspections, customer requests or weather events.
Repairing roads on the Islands is different from mainland work because materials and equipment often need to travel by barge. This adds time, cost and practical limits, especially for products that must stay hot until they are used.
Green Seal road resurfacing on SMBI is considered as part of planned maintenance, not day-to-day pothole repair. Roads are prioritised using condition information, safety and service needs, expected pavement life, available budget and the practical timing of Island works, including grouping works where possible to make barge transport and crew time more efficient.
For routine pothole repairs, Council currently uses specialised cold mix, such as Viafix. It is easier to transport and store, does not need heating, can be used in wet conditions, and unused material can be returned and reused. Although it costs more upfront, it can be more practical and cost-effective for Island operations.
1. Road Maintenance Approach
Road maintenance is generally delivered in two ways:
- Reactive maintenance: repairs carried out in response to issues such as potholes, inspection findings, customer requests or weather damage. These works are prioritised according to safety risk and service levels.
- Planned maintenance programs: larger works, such as resealing, that are scheduled using road condition data, lifecycle planning and available budget.
Available budget affects how much planned work can be completed and when it can be delivered.
On SMBI, planned resurfacing works such as the Green Seal Program are prioritised by considering road condition, safety and access needs, expected remaining life of the road surface, available funding and the practical logistics of delivering work on the Islands. Where possible, works may be grouped or scheduled to reduce repeated barge movements and make best use of crews, equipment and materials.
2. Road Maintenance Products and Methods
2.1 Spray Seal (Green Seal Program)
- Spray seal uses hot bitumen sprayed onto the road surface, followed by small stones called aggregate.
- It needs specialised trucks, tankers and rollers, so it is best suited to larger planned works.
- Best suited for: planned road resurfacing programs.
- Limitations: not practical for small pothole repairs because of the equipment, setup and transport required.
- How it is prioritised on SMBI: Green Seal works are considered through planned maintenance programs and prioritised based on road condition, safety, service need, budget and Island delivery logistics.
2.2 Hot Asphalt
2.2.1 Flocon Trucks
- Flocon trucks are designed to carry and keep hot asphalt workable for road repair tasks.
- They can carry about 2 tonnes of hot asphalt from an asphalt plant, with the nearest plant at Eagle Farm.
- They can keep asphalt hot for up to approximately five hours.
- Limitations for the Islands: travel time, barge transport and cost make this option inefficient for routine pothole repairs.
2.2.2 Standard Body Trucks
- Standard body trucks can usually keep asphalt hot for about 2 to 2.5 hours, and for less time in winter.
- Limitations for the Islands: asphalt may cool before it can be used, leaving too little workable time once the truck reaches the job site.
2.3 Conventional Cold Mix
- Conventional cold mix can be applied without heating.
- Advantages: it can be transported in standard trucks and avoids heat-related safety risks.
- Disadvantages: it has a short shelf life, does not bind as well, and may fail if it is not compacted properly.
2.4 Specialised Cold Mix (Viafix — Currently Used on Islands)
Specialised cold mix, such as Viafix, is premixed and designed specifically for pothole repairs.
It uses a binder that helps the material stick in place without needing heat.
Key advantages: it can be used in wet conditions, stores well in bags or pallets, does not need heating, and generally performs better than standard cold mix.
Operational benefit: unused material can be returned to the depot and reused. This reduces waste and helps offset the higher upfront cost.
3. Product Suitability for Island Operations
For Island work, the most suitable product is the one that can be transported, stored and used reliably despite barge travel and longer travel times.
- Hot asphalt is generally impractical because it can cool before crews have enough time to use it.
- Spray seal is suitable for planned, larger road resurfacing works, not small pothole repairs.
- Green Seal works on SMBI are prioritised through planned maintenance programming, with consideration given to road condition, safety, remaining surface life, funding and efficient delivery across the Islands.
- Specialised cold mix, such as Viafix, is currently the most practical option because it is flexible, durable and reduces waste.
4. Frequently asked questions
4.1 Do we have road crews on the islands
There are two fulltime road crews on SMBI located one each on Russell and Macleay Island. These crews undertake road repairs and maintenance of sealed and unsealed roads. Separate crews are responsible for green sealing. Local contractors are employed as much as possible.
4.2 How are road repairs prioritised?
Council uses a mix of urgent response work and planned programs:
- Urgent response work: potholes and other safety issues are prioritised based on risk and service levels.
- Planned programs: larger works, such as resealing, are planned using road condition data, lifecycle planning and budget availability.
4.3 Are materials mixed for each job or delivered by truck?
- Viafix: supplied premixed in bags or pallets and used as needed.
- Hot asphalt: produced at an asphalt plant and transported in bulk by truck.
- Spray seal: delivered in larger tanker loads for planned works.
4.4 Is Green Seal the same as pothole repair material?
- No. Green Seal is a spray seal treatment used for road resurfacing.
- Pothole repair products, such as Viafix, are different products used for smaller repair jobs.
4.5 How is Green Seal prioritised on SMBI?
Green Seal is prioritised as part of Council’s planned road resurfacing program, rather than as a pothole repair response. On SMBI, roads are assessed using condition information and practical delivery considerations.
- Roads in poorer condition, or where the surface is nearing the end of its useful life, are considered for planned resurfacing.
- Safety, access and service needs are considered when comparing priorities.
- Available budget affects how much work can be delivered each year.
- Island logistics, including barge access, equipment movement and crew scheduling, are considered so works can be delivered efficiently.
4.6 Can leftover material be reused?
Yes, but it depends on the product:
Viafix:
- Unused material can be returned to the depot and reused.
- Crews may also repair nearby defects if time allows.
- This approach helps reduce waste.
Hot asphalt:
- It has a limited working time before it cools.
- Once it cools or is unused, it generally cannot be reused.
Spray seal:
- It is delivered in bulk for planned works.
- It is not suitable for small, ad hoc pothole repairs.