The Thousands of Tonnes of Tyre Waste We Do Not See

When replacing vehicle tyres, have we ever asked where the eroded parts of the tyre go? This question is vital when considering the number of vehicles in Indonesia. In 2023, BPS recorded approximately 157 million motor vehicles in Indonesia. The majority are motorcycles, reaching 132 million units, followed by passenger cars at around 18.3 million units.

All these vehicles use tyres. If one motorcycle uses two tyres and one car uses four, the total is approximately 338 million tyres. This only accounts for motorcycles and passenger cars, excluding buses and trucks that transport passengers and goods daily.

As vehicles travel, the tyre surface constantly rubs against the road and gradually erodes. We usually only notice this when the tyre treads thin and need replacement. However, eroded material is released throughout the journey. The more a vehicle is used, the more tyre material potentially disperses into the environment.

To visualise the scale, we can use the tyre wear rate used by the Organisation for Economic Co-operation and Development (OECD), which is an average of 0.1 grams per passenger car per kilometre. This figure covers all tyres on the car. The amount of wear varies depending on vehicle load, road conditions, tyre type, and driving style.

If a car is assumed to travel 10,000 kilometres a year, the released tyre material reaches about one kilogram. Applied to 18.3 million passenger cars, this totals approximately 18,300 tonnes per year. This is only for passenger cars, excluding motorcycles, buses, and trucks. This calculation is an illustration rather than a national measurement; a more accurate estimate would require data on active vehicles and their mileage.

The eroded material breaks into small particles and mixes with road dust. When it rains, some is carried by water into drains and rivers, while others are trapped in the soil or settle at the bottom of water bodies. As roads dry, sufficiently small particles can be lifted by the wind and inhaled by humans. This tyre particle pollution often goes unnoticed by the public. The United Nations Environment Programme (UNEP) identifies tyre wear particles as a significant source of microplastic pollution.

Once their lifespan ends, another problem arises: waste tyres. Tyre recycling technology is actually available. Certain tyres can be vulcanised for reuse, and waste tyres can be processed into other products or used for energy recovery. However, the availability of technology does not automatically solve the problem. Collection, processing costs, process safety, and environmental monitoring must still be ensured. Poor collection systems create opportunities for waste tyres to be dumped indiscriminately or burnt without control.

Therefore, management must begin from the moment the tyre is in use. Drivers can maintain tyre pressure according to recommendations, avoid overloading, and reduce sudden acceleration and braking. Such habits help reduce wear while maintaining safety. Manufacturers also need to develop tyres that are more wear-resistant without compromising grip.

The government and universities need to complement these steps with research. We need data on tyre wear under Indonesian road conditions, especially for motorcycles, which dominate the Indonesian vehicle market. Monitoring road dust and rainwater runoff can help determine intervention locations. Strengthening public transport is also essential to reduce private vehicle trips.

For waste tyres, a return system through workshops and tyre retailers should be developed. Manufacturers must be involved so that their responsibility continues after the sale. The public also needs information regarding tyre disposal locations and how they will be processed.

This issue persists with electric vehicles, as their tyres also rub against the road. Therefore, clean transport needs to encompass more than just exhaust emissions. When replacing thinning tyres, we must remember that part of the material has been left behind throughout the journey. Managing waste tyres is important, but reducing pollution during tyre use also requires attention.