Bigger Death Rates in Smaller Cars (Except for Nissan LEAF EV)

Despite manufacturers’ efforts to make them safer, the smallest late-model cars remain the most dangerous, according to the most recent driver death rates calculated by the Insurance Institute of Highway Safety. However the Nissan LEAF still had very few death rates in comparison to other vehicles in its size range.

Small cars and minicars accounted for 15 of the 20 models with the highest death rates for model year 2017, while nearly half of the 20 models with the lowest death rates were luxury SUVs.

“Smaller vehicles offer less protection for the driver in crashes, and their lighter mass means that they take the brunt of collisions with larger vehicles,” says Joe Nolan, IIHS senior vice president of vehicle research.

Very large SUVs have the lowest overall death rate of any vehicle category with 15 fatalities per million registered vehicle years. Minicars have the highest at 82.

The average driver death rate for all 2017 models increased to 36 deaths, compared with 30 for 2014 models. That’s a further increase from a low of 28 for 2011 models following a steady decline since the 1970s. The rise is consistent with a larger number of U.S. traffic fatalities over the four-year period covered by this study, compared with the previous one. From 2015 to 2018 there were 147,324 fatalities, compared with 134,905 from 2012 to 2015.

The death rates for 2017 models vary widely from 0 for seven models to 141 for the worst performer, the 2017 Ford Fiesta, a 4-door minicar that earned a rating of “marginal” in the IIHS driver-side small overlap crash test. Including the Fiesta, half the 2017 models with the highest death rates were also among the worst for model year 2014, the last time IIHS looked at the data.

IIHS has been calculating driver death rates approximately every three years since 1989. The rates include only driver deaths because all vehicles on the road have drivers, but not all of them have passengers or the same number of passengers. The number of deaths is derived from the federal Fatality Analysis Reporting System. Registration data come from IHS Markit.

Alongside vehicle safety ratings, driver death rates are another source of information consumers can use to inform their purchasing decisions.

The two types of information complement each other. IIHS ratings are designed to compare vehicles in the same size category. Frontal crash test results can’t be compared across sizes because the kinetic energy involved in the test increases with vehicle weight.

In contrast, the driver death rates can be compared across vehicle classes. However, as a comparative tool, they have their own limitations. While the death rates are adjusted for driver age and gender, they don’t capture other factors that might influence fatality rates, such as the speeds people drive, the number of miles they travel per day and the types of roads they use.

To look at the effect of one of those factors, this year IIHS also compared the driver death rates per 10 billion miles traveled. Through a cooperative agreement in place since 2015, the IIHS-affiliated Highway Loss Data Institute was able to match Vehicle Identification Numbers from its database to odometer readings from CARFAX, an IHS Markit unit that maintains a vehicle history database. Odometer readings came from multiple sources, including title transfers, yearly inspections and routine maintenance service.

For the most part, the mileage data bolstered the original findings about vehicle size and explained some notable exceptions.

Sports cars and luxury cars, which traveled fewer miles per year than other models, showed relatively higher driver death rates by the alternative method. Death rates for pickups trended lower by miles driven.

Within each vehicle category, the order of individual vehicles did not change much. For this reason, IIHS has decided to stick with the usual registration-year method for the published make and model results.

By that method, nine of the 20 models with the lowest death rates are luxury SUVs, two more are midsize luxury cars, and four others are minivans or very large SUVs. The overall death rates for luxury vehicles are also substantially lower than the averages for nonluxury vehicles of the same sizes.

Luxury vehicles often come equipped with advanced safety features that aren’t widely installed on less expensive ones, such as blind spot warning and lane departure prevention.

Notably, two small cars defy the average for their size and class, whether driver death rates are measured against registered vehicle years or miles traveled. The Volkswagen Golf and the Nissan Leaf have death rates of 0 and 5 per million registered vehicle years, respectively. Their rates per 10 billion miles were the same. For comparison, the overall rate for small cars was 61 deaths per million vehicle years and 45 per 10 billion miles.

The Golf’s results are particularly remarkable, considering that the 2014 version was among the worst performers, with a death rate of 63 per million vehicle years, prior to a redesign for the 2015 model year.

Although the number of miles driven was not a factor, the results for the Leaf, an all-electric car, may reflect when and where electric vehicles are driven.

The latest rates are based on fatalities that occurred from 2015 to 2018 for vehicles from the 2017 model year, as well as earlier models with the same designs and features. The numbers represent the estimated risks for 2017 models, but the data include models from as far back as 2014 if the vehicles have not been substantially redesigned over the intervening period. Including these older, equivalent vehicles makes the sample size larger and therefore increases the reliability of the results. To be included, a vehicle must have had at least 100,000 registered vehicle years of exposure from 2015 to 2018 or at least 20 deaths.

 

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