A total solar eclipse on April 8 could lead to an increase in fatal car accidents, scientists warn

During the 2017 total solar eclipse in North America, there was a brief but significant increase in fatal crashes in the United States. During the total solar eclipse expected on April 8 of this year, an increase in fatal car accidents may also be registered, scientists warn in an article published in JAMA Internal Medicine․

Study co-author Professor Donald Redelmeier, MD, PhD, University of Toronto, said the increase in accidents was not related to a lack of light during the solar eclipse. "The problem is the hours around when people are traveling to the eclipse viewing area and especially the hours after," Redelmeier told Live Science, adding that they are particularly concerned about the hours when people are returning home.

During the 2017 eclipse, the part of the Earth where the total solar eclipse could be seen was about 113 kilometers wide. In that area, people could observe a total solar eclipse for the longest time. About 20 million people in the United States traveled to another city to be in that zone.

During this year's April 8 eclipse, those in the above area will be able to view the total eclipse for about 2.5 to 4.5 minutes, depending on their location. Viewers outside that zone will only be able to see a partial eclipse.

Given that the 2017 eclipse caused such heavy traffic, Redelmeier and study co-author Dr. John Staples, a clinical associate professor at the University of British Columbia, wanted to see if that was associated with life-threatening traffic accidents. And to that end, they pulled data from the National Highway Traffic Safety Administration's Fatality Analysis Reporting System, which records all fatal traffic accidents on US public roads.

They focused on the three-day window before and after the August 21, 2017, eclipse and compared that data to crashes that occurred a week before and after the three-day window. In addition, they used a US Navy calculator to determine the time of each crash relative to the time of maximum eclipse based on the latitude and longitude of the crash site.

As a result, they found that the eclipse led to a 31% increase in fatal crashes. Almost as much increase occurs during major holidays (Thanksgiving, July 4) when people travel to other parts of the country. In other words, about 10.3 people were involved in fatal accidents per hour during the eclipse, compared to 7.9 people involved in accidents on normal days. "This averages out to one additional crash victim every 25 minutes and one additional crash victim every 95 minutes," the researchers write.

In terms of time, the risk has fluctuated։ it was higher than average before the eclipse, dipped during the eclipse, and peaked after the event itself, which was nearly 50% above average. The risks were higher in areas with clear skies than in cloudy areas, which may be explained by the fact that people tended to go to areas with clear skies to view the eclipse.

Before the April 8 eclipse, Redelmeier said their goal was to advise people to follow all road safety rules to avoid accidents as much as possible.

The new study only reports fatal crashes. Redelmeier said they simply didn't have data on non-fatal crashes. The study also does not distinguish between the cases when people, not for the purpose of observing the solar eclipse, found themselves in the dark and had an accident.