A research team led by Fabio Caiazzo of MIT recently quantified the impact of air pollution and premature death in the United States for the year 2005. They found that road-related particulate matter was responsible for about 19% more deaths, nationwide, than car crashes. Read all about it.
Our own Wig Zamore adds:
Unfortunately, the air pollution death valuation is WAY LOW because only traffic contributions to regional, as opposed to local, pollution are counted. Experienced and well regarded southern California environmental health scientists will soon publish a heath impact assessment study suggesting that in 2035 local traffic related air pollution in southern California will be responsible for as many deaths per year as total regional fine particle pollution. Given how much smaller the near roadway population is this is a stunning outcome!
This suggests that the total local and regional traffic pollution deaths are about three times what this article suggests. In general the colder a region is, the higher the ratio of local traffic emissions effects to regional traffic emission effects. Cold weather drives higher local primary pollution concentrations and gradients, warm weather drives higher regional secondary pollution concentrations.