Frequency and cost of crashes, fatalities, and injuries involving disabled vehicles.

Objective: To quantify the total number and cost of crashes, fatalities, and injuries that could be addressed by improved conspicuity of disabled vehicles to approaching traffic.

Methods: Using the Fatality Analysis Reporting System (FARS) and the Crash Report Sampling System (CRSS) this study defines three crash scenarios where insufficient conspicuity of a disabled vehicle ("low conspicuity emergency") resulted in injury or death: Scenario 1) Moving vehicle strikes non-moving vehicle following an initial event; Scenario 2) Pedestrian (primarily a motorist who has exited their vehicle) is struck while tending to a disabled or stopped vehicle; and Scenario 3) A vehicle departs the roadway and crashes unnoticed and rescue initiation is delayed significantly.

Results: Annually, between the years 2016 and 2018, an estimated 71,693 people were involved in low conspicuity emergency events, including 566 fatalities and 14,371 injuries. Most (95 %) of these cases occurred under scenario 1. Notable, however, is the severity of scenario 2 crashes where the majority were severely injured (22 %) or killed (19 %). Based on the FARS data, nearly 300 people were killed under scenario 2 each year and cases have increased 27 % since 2014. Overall, crashes under these three scenarios resulted in an annual estimated $8.8 billion in societal costs, including the economic costs of medical payments and wage loses in addition to the value of quality of life lost due to death or disability. Scenario 1 crashes resulted in an average of $4.3 billion in losses, scenario 2 crashes in $3.4 billion in losses, and scenario 3 crashes in $1.2 billion in losses annually.

Conclusions: A significant number of people die or are injured in low conspicuity events every year; an estimated 1.55 deaths and nearly 40 injuries per day. This analysis highlights the risks to a special subset of pedestrians: motorists who exited their vehicles to attend to a disabled or stopped vehicle. These deaths and injuries that result from crashes related to low-conspicuity events are preventable. Countermeasures to reduce the incidence and severity of the crash scenarios studied should be explored.