Premature deaths as a result of air pollution from traffic congestion are expected to decline modestly from now until about 2020, according to a new study from the Harvard Center for Risk Analysis. That’s the good news.

After that, deaths resulting from pollution are likely to begin rising modestly again as total vehicle miles traveled (VMT) more than offset any gains made through conversions to lower-emissions vehicles. That’s the bad news.

The researchers at Harvard examined 83 urban areas in the United States and determined that 2,264 premature deaths occurred in 2010 alone as a result of traffic-congestion pollution. The researchers cite another recent study by the Health Effects Institute in Boston that found “strong evidence for a causative role for traffic-related air pollution and premature death, primarily from heat attacks and strokes.”

By its own admission, the new Harvard estimate is a conservative accounting of premature deaths in that it only considers the death toll from emissions in 83 urban areas.

The study also predicts that the estimated public-health cost of the premature deaths will climb to more than $17 billion by 2030, after leveling off in 2020. The cost related to premature death from traffic congestion is dwarfed by the cost of time wasted by people sitting in traffic jams, the economic cost of which is expected to reach nearly $100 billion annually by 2030.

Check out the report here.