The author neglected to mention that miles driven in the United States increased by a record 107.5 billion last year, up 3.5% [0]. Even at 2014's all-time low death rate of 1.08 deaths per 100 million vehicle miles traveled [1], that increase in driving would lead us to expect 1,161 more deaths on the roads. There were actually 2,417 (7.4%) more deaths in 2015 than in 2014, so the increase in driving accounts for "only" 48% of the increase in deaths.<p>What accounts for the rest? More notable than the increase in deaths is that the death <i>rate</i> increased from 1.08 per 100 million VMT to 1.12 (3.7%), only the second year-on-year increase in the death rate in the past two decades. The only other increase in the death rate occurred between 2011 and 2012, and the biggest <i>decreases</i> in the death rate over the past two decades occurred in 2007–8 and 2008–9.<p>What was happening in those years? First the Great Recession, then an economic recovery. The years of the Great Recession were saw the steepest declines in miles driven in decades, and the last several years of economic recovery have seen the sharpest increases in driving (to an all-time high last year). The recession years were also the only years vehicle registrations fell in recent decades, and the number of licensed drivers flatlined for the first time since the previous recession in the early 2000s; licenses and registrations ticked up again during the recovery years, and were up strongly in 2014 [2].<p>So we saw the death rate fall as the recession hit and people drove less, fewer people got licensed to drive, and fewer vehicles were on the road. Then during the recovery we saw the only increases in the death rate in decades, as people started driving more and more new drivers got licensed and hit the roads.<p>Here's a hypothesis: the death rate fell sharply during the recession because (a) fewer cars were on the road, making roads safer, and especially because (b) the cohort of drivers changed, shifting older, more experienced, and more cautious as fewer young people (who were hit hardest by the economic downtown, and who have the highest rate of death by car) could afford to drive. Then during the recovery those changes reversed and people began to die on the roads at a higher rate.<p>Corollary: this article about apps causing driving deaths is mostly journalistic nonsense.<p>0. <a href="http://www.fhwa.dot.gov/policyinformation/travel_monitoring/15dectvt/" rel="nofollow">http://www.fhwa.dot.gov/policyinformation/travel_monitoring/...</a><p>1. <a href="http://www-fars.nhtsa.dot.gov/Main/index.aspx" rel="nofollow">http://www-fars.nhtsa.dot.gov/Main/index.aspx</a><p>2. <a href="https://www.fhwa.dot.gov/policyinformation/statistics/2014/dv1c.cfm" rel="nofollow">https://www.fhwa.dot.gov/policyinformation/statistics/2014/d...</a>