Advanced vehicle technology has the power to make a dramatic improvement to air quality – but it cannot do the job on its own. The most meaningful benefits will be achieved by an integrated approach involving industry, government, local authorities and road users.
Road transport may currently be the biggest single source of roadside air pollution in urban centres, but it is important to put it into context. Society – and the economy – is dependent on cars and commercial vehicles to get us to work and deliver our essential goods and services.
Trucks and buses in particular offer an opportunity to reduce pollution on a major scale. The heavy duty sector has been regulated by an equivalent Euro Standard to cars – Euro VI – since 2014, and it’s already proving itself. Transport for London tests using the London 159 bus route show a 95% reduction in NOx over the previous Euro V standard. But, as with Euro 6 for cars, the technology doesn’t come cheap and to speed up fleet replacement, government support at all levels to promote business certainty and encourage uptake is critical.
Reducing congestion and unnecessary journeys as well as encouraging more efficient driving are also important. Engines are at their least efficient when in stop-start traffic and keeping them moving will make a serious improvement not only on air quality, but business productivity, too. The cost to the economy of congestion is estimated at £307 billion between 2013 and 2030, with motorists stuck in traffic for 18 working days on average (Source: INRIX 2014). In some urban areas, anti-idling campaigns have been introduced to encourage drivers to turn off engines while waiting or parked. Action at local level to encourage more efficient driving behaviour would build on vehicle technology to reduce emissions further.
Managing traffic to smooth its flow can significantly reduce air pollution. Intelligent traffic systems such as motorway speed regulation schemes, smarter traffic sequencing and intelligent road design in urban areas help reduce stopping and starting and improve air quality in hotspots. Out of hours deliveries also reduce congestion and emissions at peak times, while ‘last mile’ delivery schemes and urban freight consolidation may be appropriate in cities where low or ultra-low emission vehicles can complete the final stage of distribution. Planning policies, which recognise changing mobility trends in urban areas and offer an integrated range of choices to suit journey needs, including cycling, walking, car sharing and public transport, will also be paramount, and must keep traffic moving.
Regular maintenance is essential to keeping emissions in check, and motorists and fleet managers have a responsibility to adhere to recommended manufacturer service intervals to ensure engine and after-treatment systems are optimised. These systems are critical to the emissions performance of modern vehicles. For example, removal of diesel particulate filters, which is an offence, will greatly increase emissions of PM. Selective catalytic reduction systems, meanwhile, require regular top-ups of AdBlue. Finally, we must not forget other contributors of pollutant emissions, including rail, domestic and commercial heating and electricity generation, and even construction machinery in urban areas. All of these sources will also need to be addressed.