• vehicle type (model, age, usage)
• location (e.g. city = more stop/start)
• average occupancy of vehicles.
4.4 The actual impact will also depend on the type of transport scheme implemented and –
ultimately – the distances and number of car kilometres which are reduced.
Pollution effects
4.5 Pollution can have an impact on the following factors:
• human health – aggravation of existing heart, vascular and respiratory illnesses
• biodiversity – defoliation, disease, lower yields and death of vegetation
• the built environment – surface corrosion and erosion of buildings
• cultural heritage – surface corrosion and erosion of public buildings and landmarks
• climate – local microclimate and global climate.
4.6 All of these can be seen to have a monetary cost. However, a European project on the external
costs of transport64 concluded that:
“health impacts dominate the damages quantified […]; in particular,
mortality due to primary (PM2.5) and secondary particulates (nitrates,
sulphates). Carcinogens[…] proved to be of much lower importance.”
4.7 In total, emissions from road transport contribute around 70% of the air pollution in our towns
and cities65, and there are over 120 ‘pollution hotspots’ in the UK where national air quality
targets won’t be met66. Evidence from the Department of Health suggests that each year the
deaths of between 12-24,000 vulnerable people are brought forward, and between 14-24,000
hospital admissions may be associated with short-term impact of air pollution on health