Speed, Air Pollution, and Health: A Neglected Issue

Using particulate matter with diameters of 10 mcm or less (PM10) as markers of exposure Kunzli et al. reported that annual mortality from air pollution exceeds mortality from road injury in Austria France and Switzerland. However they did not examine the role of increased speed limits and travel speeds relative to the increase in the death toll from air pollution emissions and their general effects on health. It is noted that rate of emissions of certain air pollutants [carbon monoxide (CO) oxides of nitrogen] per distance traveled increases exponentially with increases in travel speeds in private vehicles that run on petrol and in trucks and private vehicles that run on diesel fuel (PM10). In addition emissions of carbon dioxide (CO2) the major greenhouse gas increase arithmetically with increases in speed above 80 km/hour. For CO2 CO and hydrocarbons emitted by private vehicles and diesel trucks there is an approximate U- shaped relationship between speed and fuel efficiency which approaches maximum in the range of 40-75 km/hour. Therefore speed regulation of private vehicles and commercial trucking is the sine qua non for a model shift to high-speed mass transit of both persons and goods.