Increased Traffic Means Cleaning Less Dead Bugs From Windshield

If you’ve taken a longer road trip lately, you may have noticed there weren’t as many dead bugs splattered all over the front of your car. Maybe you just got lucky? Or it’s not the right season? Or cars are just more aerodynamic these days? Turns out, the answer is probably none of those things.

The Washington Post recently decided to see if it could figure out why people were noticing fewer bugs on their windshields and if it had anything to do with cars themselves. Dismissing the trend as personal anecdotes or simply due to declining insect populations seemed a little too easy of an explanation. Especially since while insect populations have decreased in general, as noted in the article, that decline isn’t happening at the same rate everywhere, and occasionally, insect populations increase in certain areas.

One of the first things the article confirms is that the decrease in bug splatters is an observable phenomenon. Anders Pape Moller, a Danish biologist, has actually used bug splatter to estimate insect populations for decades, and based on his data, between 1996 and 2017, bug splatter dropped 80 percent on one route and 97 percent on another.

Because it’s difficult to get a reliably accurate count of insect populations, that doesn’t necessarily mean the total number of bugs has dropped between 80 and 97 percent. So WP went digging for possible car-related answers.

Could it be that more aerodynamic vehicles reduces the number of bugs your car kills? On its face, that explanation makes sense, but based on the experts they talked to, better aero isn’t a significant factor:

“For starters, many aero improvements happen on the rear of the car rather than the bug-hitting front. Consider the optimally aerodynamic teardrop shape, with its blunt, round front and long, sleek tail. But more importantly, it’s just surprisingly difficult to use air to push a bug out of the way of an onrushing Buick.”

Additionally, a local British study focused on bug splatter on license plates and found a 60 percent decline between 2004 and 2021. And while windshields may have gotten less upright and cars more aerodynamic, those improvements exactly extend to front license plates.

Ultimately, the apparent answer is pretty mundane. In addition to insect populations declining, monthly vehicle miles traveled has continually increased since the 1970s. And with more people out there splattering bugs with their cars, the number of bugs per windshield has gone down.

Pedestrian deaths have been trending upwards for decades, and overall motor vehicle deaths have increased since 2008. But if there’s one positive, it’s that all the extra driving we’re doing does mean windshields stay cleaner. Yay?