Everybody is affected by traffic congestion, especially if they live in populous metro areas. In contrast, most people don't think that there is any cost to them when a truck crash kills someone or an icy interstate causes a massive pileup. But they are wrong: the bill for traffic accidents goes to everyone.

An AAA study shows that congestion costs Chicago around $1,112 per person each year, whereas the cost of vehicle crashes is $1,180 per person. Put another way, for every dollar wasted on congestion, $1.06 is expended on crashes by each person in Chicagoland, which in the AAA study included southeastern Wisconsin and northwestern Indiana.

How are these costs to society calculated? The congestion costs include wasted fuel, wear and tear on vehicles, health consequences of pollution, and time lost sitting on the expressway during rush hour. The accident costs include expenses for law enforcement, ambulances, road repair, public travel delay, property damage, lost earnings, medical bills, administrative and legal costs, workplace costs to replace injured workers, and lost quality of life.

Chicago's congestion costs are greater than the national average of $590 per person. However, the crash cost to residents of the region is lower than the national average of average of $1,522, probably because of the extensive public transportation systems in and around Chicago.

Resource: Chicago Tribune, "Vehicle crashes cost region $11.3 billion annually, AAA says", by Jon Hilkevitch, Nov. 3, 2011.