Is traffic worse during a full moon? A recent rush hour tests that theory.

Wednesday, April 1, was one of those traffic mornings. It was tragic, gridlocked and maddening.

Three fatal crashes, two vehicle fires, a bevy of other wrecks, and plain, slower-than-normal traffic elsewhere made for one of the most active dry-weather rush hours I have covered in years. My 11Alive traffic co-anchor Rachel Cox-Rosen said it was her worst in the 11 months she has reported on metro Atlanta traffic.

When it all happens at once, it makes us wonder — what caused that?

As I sat in the 11Alive Traffic Impact Tracker truck and watched a scene on I-285 West (inner loop) before Riverdale Road (Exit 60) where a truck had hit and killed a pedestrian, I noticed a full moon in the western sky.

Sure enough, we were about 15 hours away from a full pink moon reaching its height.

In my years of traffic reporting and calling 911 centers for crash info, I had heard anecdotally and colloquially about how crazy things get, especially at night, when there is a full moon. Dispatchers would regularly say that.

So the thought entered my mind as the madness piled on that day: Were people really making more driving mistakes because of the lunar cycle?

I reached out to a couple of transportation data experts and did not hear back. Then a perusal of several studies that spanned decades and oceans made my hypothesis cloudy enough to blot out that April Fools’ Day moon.

In 2022, a German insurance company found the day in May with the third-highest crash claims that year was indeed a full moon. It trailed two other days with inclement weather. The firm attributed the increase in wrecks to the human sleep pattern being disrupted by a lack of melatonin, which is produced in darkness. And since there is less total darkness during a full moon, people, in theory could be sleepier and less adept at driving.

Other studies had far greater sample sizes.

Princeton University researchers studied U.S. fatal motorcycle crashes from 1975 to 2014 and found full moons saw a 5% bump in those tragedies. But brighter, supermoon-lit nights saw a 32% increase in those wrecks. The authors attributed the brightness of the moon to the riders’ distractions — not a lack of sleep.

A 1994 Czech study combed over 60,000 crashes and found the increase in atmospheric precipitation surrounding both new and full moons could be the cause for more wrecks.

So, rain helps cause wrecks and precipitation is more likely around full and “no” moons twice per month. Interesting. April 1 was a dry morning in Atlanta.

Japanese researchers did a 2018 data plunge and found a marked increase in medical transports because of crashes on full moon nights in the Land of the Rising Sun … for men 40 and over before midnight.

In a 2024 study, researchers studied nine years of wrecks in Texas up until January 2020. They found 46% more wildlife vehicle crashes than on new moon nights. The number of wrecks not involving animals was not significantly different per the lunar cycles.

My wife, Momo, tells me her mother, Ulrike, only sleepwalks during full moon nights. Bake that into your evidence.

One can pick a study and find the conclusion they want. While there may be some effect or hangover from full moons, research does not show it to be radical.

Analyzing data like this is tough because other weather conditions, holidays and any number of other variables can sway the results.

The human condition drives us to attempt to explain the craziness of life. In the case of this April 1, Atlanta just experienced a horrible and tragic Wednesday in traffic.

Doug Turnbull covers the traffic/transportation beat for WXIA-TV (11Alive). His reports appear on the 11Alive Morning News from 6 a.m. to 9 a.m. and on 11Alive.com. Email Doug at dturnbull@11alive.com. Subscribe to the weekly “Gridlock Guy” newsletter for the column here.