Assessment of the future impact on health of a proposed freeway development.

This paper estimates the effect on health of traffic injury and air and noise pollution from a proposed inner-suburban freeway in Melbourne. We estimated levels of these health problems for the year 2001 using traffic flow projections for the presence and absence of the freeway. For noise and air pollution, it was necessary to use pollutant levels as proxies for levels of associated diseases and health states. In 2001, there will be an increase in all traffic movements in the study area but a decrease of 100,000 vehicle-kilometers per day on major roads, excluding the bypass. This is associated with a projected reduction in the study area of about 100 to 110 injuries of all types. The major air pollution problems associated with motor vehicle emissions are ozone and respirable particulates; sulphur dioxide, nitrogen dioxide and carbon monoxide are unlikely to pose a health hazard. Levels of respirable particulates, lead and polycylic aromatic hydrocarbons are generally low. There should be no detectable increase in average or maximum noise levels adjacent to the freeway if attenuation measures are employed. A reduction in average and maximum noise levels should occur on some main roads in the affected area. The effects of the freeway on the area should be favourable to health, with reduction in traffic injury and noise-related health problems outweighing any risk of a small deterioration in respiratory health associated with atmospheric pollution.