LCQ11: Handling of waste vehicle tyres
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Question:
There are views that the disposal of large quantities of waste vehicle tyres at landfills in Hong Kong constitutes a waste of resources. Converting such tyres into rubber powder and adding it to conventional bitumin as a road paving material (rubberised bitumin) can facilitate the handling of waste tyres, enhance environmental benefits and also reduce costs of public works projects. In addition, in a blog post on August 17 last year, the then Secretary for Transport and Logistics, indicated that the Highways Department (HyD) had achieved satisfactory results in its research on the application of rubberised bitumin in road paving and was exploring the wider use of this material in road maintenance works. In this connection, will the Government inform this Council:
(1) of the number of waste vehicle tyres disposed of at landfills since last year;
(2) of the total consumption of bituminous materials in road works across the territory and the quantity of waste tyres recycled for use in rubberised bitumin in each of the past three years; whether the authorities have plans to fully adopt rubberised bitumin for road paving, and whether an assessment has been conducted on the potential waste reduction benefits of using this material for road paving (including the additional quantity of waste tyres that could be handled annually after its full adoption); if so, of the details; if not, the reasons for that; and
(3) given that according to the information on the HyD's webpage, the Government has fully adopted a low noise road paving material called "Highly Modified Stone Mastic Asphalt" for road paving since April this year. However, the HyD has also stated that it has been conducting site trials on rubberised bitumin to formulate criteria for future application of this material in road paving, of the authorities' major considerations when deciding on the choice of road paving materials (e.g. whether technical and cost differences are included)?
Reply:
President,
In consultation with the Environment and Ecology Bureau, the Environmental Protection Department and the Highways Department (HyD), the reply to the various parts of the question raised by the Hon Lam So-wai is as follows:
(1) The total volume of vehicle tyre waste disposed of at landfills from 2021 to 2023 is tabulated as follows:
| Year (Note 1) |
Volume of vehicle tyre waste disposed of at landfills (tonnes) (Note 2) |
| 2021 | 19 900 |
| 2022 | 16 200 |
| 2023 | 14 300 |
Note 2: The volume includes a small volume of other tyres which cannot be classified
(2) and (3) Rubberised bituminous material is a paving material that replaces part of petroleum-based bitumen with crumb rubber made from waste tyres. The HyD, in collaboration with academia, has earlier researched and confirmed the technical feasibility of incorporating crumb rubber from waste tyres into conventional bituminous materials. Not only does this technology provide a recycling pathway for waste tyres and reduce burden on landfills, but it also lowers the consumption of non-renewable petroleum resources. Following the completion of site trials for the aforementioned research, the HyD incorporated rubberised bituminous paving materials into road maintenance contracts in 2024 as one of the optional materials for road repairs. Its application will be determined based on the actual needs of road sections and cost-effectiveness considerations.
In addition to using conventional and rubberised bituminous materials as paving materials, the HyD continues to research, develop and introduce more durable bituminous materials. Starting April 1, 2025, highly modified bituminous materials have been fully adopted for paving on suitable road sections to further enhance the overall quality of road pavement in Hong Kong.
When determining which paving material to use, the HyD selects the appropriate material from among conventional, rubberised, and highly modified bituminous paving materials taking into account factors such as the specific needs of the road and the cost-effectiveness of the paving materials. In general, conventional and rubberised bituminous materials are used on non-busy urban and rural roads, while highly modified bituminous materials are applied to high-traffic road sections. For example, among highly modified bituminous materials, the "6 mm Highly Modified Stone Mastic Asphalt", which effectively reduces tyre-road noise, is particularly suitable for urban road surfaces near residential areas, while the highly permeable "Highly Modified Friction Course" is more commonly used for highway surfaces.
On the other hand, the cost-effectiveness of paving materials is also an important criterion in selecting which paving material to use. Regarding conventional and rubberised bituminous materials, according to HyD's estimates, the overall project cost (including that of construction and maintenance) of paving with rubberised bituminous material is significantly higher than that of conventional bituminous material and its durability is lower than that of highly modified bituminous materials. Therefore, considering its cost-effectiveness, the HyD currently uses rubberised bituminous material for paving in certain non-busy urban and rural road projects. Moreover, regarding highly modified bituminous materials, according to HyD's estimates, although the overall cost is slightly higher than that of conventional bituminous materials, their better durability reduces the frequency of road maintenance and minimises the inconvenience caused by road resurfacing works to the public, thereby lowering social costs. With the full adoption of highly modified bituminous materials for suitable road sections, their costs are expected to gradually decrease.
Over the past three years, the total annual consumption of bituminous materials in road projects undertaken by public works departments in Hong Kong averaged approximately 330 000 tonnes, of which the total amount of rubberised bituminous material accounted for an average of about 5 000 tonnes. This included about 25 tonnes of crumb rubber recycled from waste tyres.
The HyD will continue to keep abreast of the latest research, development, and practical experience related to road paving materials and review the application plans for different bituminous materials (including rubberised bituminous materials) in a timely manner to enhance road pavement quality while bringing greater benefits to society.
Ends/Wednesday, September 10, 2025
Issued at HKT 12:30
Issued at HKT 12:30
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