Financial Cost of Crashes in Sandy Springs

According to page 3 of the executive summary of the Sandy Springs Safety Action Plan (the summary), crashes in Sandy Springs have an overall cost of $650 million per year. This dwarfs even the direct subsidies for driving such as $60 million to widen 3/4 of a mile of Hammond drive to support more through traffic and $5 million for 111 parking spots near City Hall. Car insurance does not remotely cover the full cost of crashes, even when drivers don't flee afterward. These figures starkly demonstrate how our government is not being financially responsible and also not adequately investing in public safety. 

I just wanted to see if I could approximately recreate the $650 million figure since there's no footnote in the summary explaining it.

According to page 9 of the summary, from 2018-2022 there were 27,502 total crashes, 38 fatal crashes, and 205 serious injury crashes. I don't see a breakdown of the number of fatalities and injuries per crash, so until I get that granular detail this will be necessarily vague.

Assuming one fatality per fatal crash, that's 7.6 fatalities per year. According to WISQARS that's $10.56 million per fatality assuming these are occupants in a motor vehicle, although the figures is similar for pedestrians, for a total of $80 million per year.

I'm not sure how to approach non fatal injuries. Sandy Springs breaks down "serious injury" but not unserious injury versus no injury. WISQARS breaks down "Hospitalization" versus "ED Treat and Release". So the following comparison is necessarily imprecise.

Assuming serious injury is equivalent to hospitalization, the cost per serious injury for motor vehicle occupants is $266,728. Assuming one injury per serious injury crash that's 41 per year or around $11 million.

Assuming crashes that are not fatal and do not cause a serious injury lead to one emergency department visit for a checkup or minor treatment, the cost per crash for motor vehicle occupants is $98,153. Assuming one injury per crash that's 5,452 per year or around $535 million. I am the least confident in this figure because the of the lack of detail on Sandy Springs crashes and how to tie these less-destructive crashes to the WISQARS categories.

This rough calculation did get to $626 million ($80 + $11 + $535) , versus $650 million in the summary. Also I did not count property damage at all, either to vehicles or to buildings and infrastructure, which is probably close to the $24 million difference in total cost of crashes. E.g., 5,500 crashes per year causing $4,363 of repairs on average would total $24 million. Might just be coincidence and the team putting together the Safety Action Plan had an entirely different framework.

I want to be clear that although my result is imprecise, I do not believe it is necessarily an exaggeration. I.e., a more accurate figure could well be higher.   

This post prompted by Steven Vance doing a similar review for Chicago. It would be great if Sandy Springs were as transparent about injuries and fatalities.

The WISQARS attempts to calculate the total cost of various injuries based on factors such as cause and severity. See this paper for methodology.  

 -Vladimir