Clean air through switching: Is public transport the solution for our cities?

Clean air through switching: Is public transport the solution for our cities?

The mobility transition aims to increase the use of public transport in order to reduce car traffic in inner cities. A recent study commissioned by EIT Urban Mobility, Transport for London and the Greater London Authority examines the environmental benefits of public transport and its role in tackling high levels of microparticle pollution in Europe. In 2022, 96% of the EU population was exposed to elevated levels of microparticles exceeding World Health Organization (WHO) limits, showing alarming health implications.

Although electrification of transport significantly reduces exhaust emissions, non-exhaust emissions remain a serious problem. Especially in urban traffic, road transport causes up to 88% of microparticle emissions in cities such as London, Milan and Barcelona. Brake and tire wear are the main contributors to these non-exhaust emissions. This is further exacerbated by frequent stop-and-go traffic in urban areas.

The challenges of brake and tire wear

To significantly reduce emissions, many experts suggest switching to public transport, cycling or walking. The findings of the study make an urgent appeal to national governments: They should adopt the new Euro 7 standards, which are intended to introduce limits for brake and tire wear from 2026/2028. These regulations initially only apply to newly registered vehicles.

The Euro 7 emissions standard aims to regulate all vehicle emissions, including the invisible particulate emissions that occur every time you brake. According to that ADAC Fine dust is a health risk and contributes to the development of respiratory and cardiovascular diseases. Studies show that around 8,000 tons of brake abrasion are released every year in Germany, of which 3,000 tons alone can be attributed to PM2.5, which is particularly harmful to health.

The path to wear-resistant materials

The introduction of Euro 7 limits for brake wear is crucial. These differ depending on the vehicle type: For electric vehicles, a PM10 limit of 3 mg/km applies, while other types of drive must comply with a PM10 limit of 7 mg/km. From 2035, uniform limit values ​​of 3 mg/km will apply. Future test methods for tire abrasion are currently still being developed.

To reduce emissions, the study calls for a conversion to wear-resistant components and consideration of material toxicity. The ADAC also suggests technical solutions such as adapted friction partners, wear-resistant materials and drum brakes to minimize abrasion. Perforated brake discs could also be an effective method of reducing particulate matter emissions.

A cost-benefit model carried out in London shows a societal benefit of €235 million by 2050 if the switch to wear-resistant brakes and tires takes place. It is therefore essential that cities create attractive alternatives to private vehicles and that European institutions develop common methods for measuring brake, tire and road wear emissions in order to advance environmental protection.