Unpacking the rise in traffic deaths

By Chris McCahill
Traffic deaths shot up for the second straight year in 2016, according to recent estimates from the National Safety Council (NSC). Total fatalities are estimated to have surpassed 40,000 for the first time since 2007, marking a six percent increase over 2015 and a 14 percent increase over 2014.
SSTI anticipated this alarming trend last year, pointing to the clearest cause: an uptick in driving. Over the last two years, vehicle miles traveled (VMT) increased 6.4 percent, following a decade of historically low levels. As we noted last year, the strengthening economy has motivated people to drive more, but it also exacerbates the associated risk.

Figure 1. VMT and traffic fatalities in the United States. Sources: FHWA and NSC
Figure 1. VMT and traffic fatalities in the United States. Sources: FHWA and NSC

Some, including Angie Schmitt at Streetsblog, suggest VMT is rising too slowly to explain the sharp increase in deaths. The NSC and the National Highway Traffic Safety Administration (NHTSA) point to reckless, impaired, and distracted driving, arguing for tighter regulations, stricter enforcement, and driver education. Both note the rising use of cell phones over the past few years as a possible cause.
Others question whether distracted driving can explain the rising death toll. The Insurance Institute for Highway Safety, for example, says there’s no hard evidence, according to a Washington Post article from last October. Jess Cicchino, the Institute’s vice president for research, suggests that while cell phone use may be on the rise, distracted driving is nothing new. We may just be seeing it take on a new form.
Similarly, UConn Professor Norman Garrick and his colleagues argue in a Vox article that, “one much-discussed phenomenon, distracted driving, is almost certainly not the main culprit behind the spike in recent deaths.” Their research comparing traffic deaths among 17 countries shows the U.S. once led in traffic safety, but improvements have been slow compared to its peers. The major difference, they argue, is not how distracted we are, but how we build our roads and communities—namely, for cars. Other countries tend to have more compact land uses, roads designed to favor vulnerable users, and rules to protect those users. Like Cicchino, the researchers suggest that the recent spike in deaths is a predictable outcome of economic conditions, as more people return to the roads.
John Metcalfe at Citylab points to young adults (age 19-24), which is the most likely age group to run red lights, text while driving, and speed according to a report from the AAA Foundation for Safety. The newest report, however, doesn’t indicate whether this has worsened in recent years.
To make better sense of what drove the increase in deaths, we compiled data from the NHTSA’s Fatality Analysis Reporting System (FARS) through 2015—the first year of the recent spike—and separated crashes by type. The largest share of deaths (28 percent) involved a drunk driver, followed by speeding (27 percent), young adults (22 percent), and non-motorized road users (17 percent). Generally, fatalities declined leading up to 2014, then increased in 2015. Exceptions are drunk driving and speeding, which increased by relatively small amounts, and non-motorized crashes, which have increased steadily since 2009. There is overlap among these crash types.
Figure 2. Traffic fatalities by type in the United States. Source: NHTSA
Figure 2. Traffic fatalities by type in the United States. Source: NHTSA

Fatalities increased by 7.2 percent from 2014 to 2015. As shown in the table below, the largest increase was among crashes involving phone usage (17 percent), but those made up only 1.4 percent of all crashes and 3.0 percent of the total increase. The NSC notes that cell phone use is underreported in the FARS database, but that reporting seemed to increase from 8 to 52 percent between 2009 and 2011, based on their analysis. Assuming a constant reporting rate of 50 percent, phones were involved in around three percent of fatalities and six percent of the increase. Crashes involving non-motorized road users accounted for the largest share of the increase (23 percent), followed by those involving young adults (22 percent).
Crashes during the morning and evening peak periods increased more than any other period (10 percent), accounting for 35 percent of the increase. However, crashes at night (from 7pm to 6am) account for 37 percent of the increase—an alarming number given that only 15 percent of trips take place during that period. This increase, and the increase during weekends, may be linked to a rise in leisure activities as the economy improves.

Fatalities by type Total fatalities Percent of total, 2015 Percent change Percent of total increase
2014 2015
Total 32,744 35,092 100% 7.2% 100%
DUI 9,747 9,860 28.1% 1.2% 4.8%
Distracted 9,283 9,557 27.2% 3.0% 11.7%
Speeding 564 632 1.8% 12.1% 2.9%
Using phone 406 476 1.4% 17.2% 3.0%
Non-motorized 5,470 6,001 17.1% 9.7% 22.6%
Teens 2,166 2,377 6.8% 9.7% 9.0%
Young adults 7,108 7,619 21.7% 7.2% 21.8%
AM peak (6-9) 2,466 2,668 7.6% 8.2% 8.6%
PM peak (4-7) 3,716 4,031 11.5% 8.5% 13.4%
Weekday off-peak 6,361 6,858 19.5% 7.8% 21.2%
Weekend 5,149 5,397 15.4% 4.8% 10.6%
Night 15,052 16,138 46.0% 7.2% 46.3%

What does this all tell us? To begin with, there’s no silver bullet for improving road safety, short of reducing the amount we drive. Regulations, enforcement, and education aimed at young drivers and distracted driving could have a substantial impact if they are effective. But additional responsibility falls on road designers. Speeding, which can be managed through more rigorous enforcement, is also due largely to over-engineering. Meanwhile, our lack of safe infrastructure for bicycles and pedestrians may be among our nation’s most pressing road safety issues.
Chris McCahill is a Senior Associate at SSTI.