This benefit covers air emissions from land transport vehicles that impact on human health, limited to those arising from roads and rail. There are a range of pollutant sources that contribute to poor air quality, of which land transport is one. Land transport air emissions are a complex mixture of gases and particles, with pollutants typically split into harmful air pollutants that cause adverse health effects and impact at the local level (this benefit), and pollutants that cause global impacts (benefit 8.1 Impact on greenhouse gas emissions).
Land transport is the primary contributor to nitrogen dioxide gases (NO2) in urban centres and a portion of the contribution to particulate matter (PM – extremely small particles or liquid droplets). Dust is another land transport emission, via unsealed and sealed road dust (such as dust from brake and tyre wear).
Particulate matter (PM10, smaller than 10µm, and PM2.5, smaller than 2.5µm) predominantly impacts respiratory and cardiovascular systems. Effects can range from reduced lung function, increased medication use and more hospital admissions, through to reduced life expectancy and death. Nitrogen dioxide (NO2) causes increased susceptibility to infections and asthma in people.
Investments and programmes that may contribute to this benefit include mode shift programmes; construction of new infrastructure; changes in public transport services; high occupancy or low emission vehicle lanes; and changes in transport system operations and vehicle fleet composition.
Quantitative measures currently focus on pollutant concentrations of NO2 and PM10, rather than the longer-term health impacts. The impact of air emissions is monetised using the damage cost approach. This assigns a cost to each tonne of pollutant as a proxy for the damage done to people who are exposed to air pollutants.
The people impacted by this benefit are residents, visitors or workers in areas affected by air emissions from transport.
This benefit can be monetised.
For information about how to monetise this benefit see the Monetised benefits and costs manual.
3.2.1 Ambient air quality – NO2#
3.2.2 Ambient air quality – PM10#
Measures marked # are quantitative.
For more information about these measures see Land Transport Benefits Framework measures manual.