Misaligned Time Zones Linked to Highway Deaths

By Jeffery Gentry, Ph.D.

More people die in auto accidents if they live in the “wrong time zone,” according to new research published in Time & Society. Erratically-drawn time zones in the U.S. may be to blame.

Over twelve years of data, our research team found a 21.8% higher vehicle-fatality rate (VFR) in U.S. counties where the clock says 12 pm well before “high noon.” More than 53 million Americans live in these “eccentric time localities” (ETLs), where social time is severed from solar time.

These residents are forced to rise before dawn for most of the year, disrupting the normal sleep window, i.e., their natural circadian rhythms. ETLs affect the Eastern, Central, and Mountain Time zones, but not Pacific Time. With no ETLs, the Pacific zone has the lowest vehicle-fatality rates in the country.

We were shocked by the thousands of unexpected deaths in these antiquated time zones, which are passively accepted by policymakers and the public alike. Our data suggest that the resulting circadian misalignment may promote driver fatigue and thus driver accidents. Daylight Saving Time exacerbates the social-solar disconnect by a full hour for most of the year.

Terre Haute, Indiana is placed in the Eastern time zone, but based on the sun’s movement it should be in Central Time. Terre Haute’s vehicle-fatality rate is 53% higher than nearby Champaign Illinois’, which is appropriately placed in Central Time.

Living in the wrong time zone may impact the State of Texas most of all, two-thirds of which should be in Mountain Time. Midland-Odessa’s vehicle-fatality rate is double the national average and three-times higher than El Paso’s—the only part of Texas that is placed in Mountain Time. Amarillo, Texas likewise skews high, with a death rate 92% above the national average.

Across the U.S. ETLs experienced an average of 1285 unexpected deaths each year compared to solar zones, at an annual economic cost of $1.8 billion. Each traffic fatality averages 38 future years-of-life lost.

The study is grounded in chronobiology theory, which has gained increasing prominence in 21st-century research. We do not claim time zones are the dominant factor in highway accidents, but the death rate in ETLs is nearly one standard deviation higher than the solar zones’.

We hypothesized a problem based on established theory. We looked for it, and we found it. Based on these findings, we argue that misaligned time-zone boundaries should be moved east to better match solar time. Or at least that schools and businesses in ETLs should open at 8:30 am rather than 8:00.

Those of us in the humanities and social sciences don’t often have the opportunity to conduct hard science. We benefited from the availability of a full census of highway deaths from the Fatality Analysis Reporting System (FARS). This database enumerates each traffic death and is maintained by the U.S. National Highway Traffic Safety Commission (NHTSB).

Our team at Eastern New Mexico University would next like to see new research on health effects and educational outcomes for people living in the wrong time zone.