(Credit: ArtByArthur on Shutterstock)

In A Nutshell

Out-party stickers don’t matter when driving is good; they raise hostility when driving is bad.

Honking and “feeling thermometer” ratings captured this shift toward colder reactions.

Race effects were explored but underpowered and not statistically significant.

Self-reports are practical; simulators and field experiments could test real driving behavior.

CINCINNATI, Ohio — Political polarization has crept into nearly every corner of American life, from family dinners to workplace small talk. Now, research suggests it’s even affecting how people drive.

A new study published in Frontiers in Political Science found that drivers are more likely to react with hostility toward bad drivers when those drivers display bumper stickers from the opposing political party. The research shows partisan identity can escalate everyday road interactions, turning minor traffic annoyances into more hostile encounters.

“Partisan hostility is not simply a feature of Washington D.C.—in reality, for some Americans, it could be merely a wrong turn away,” wrote researchers Rachel Suzanne Torres and Benjamin David Farrer from the University of Cincinnati.

The study used computer-generated dashcam footage to simulate realistic driving scenarios. Participants watched videos of another car either driving smoothly or driving badly, cutting them off and forcing them to brake hard. That car displayed one of four options: no bumper sticker, a neutral “I Love My Dog” sticker, a “Proud Democrat” sticker, or a “Proud Republican” sticker.

After watching, participants rated how likely they would be to honk their horn at the other driver and how they felt about that driver on a scale from cold to warm.

Rehoboth Beach, Delaware, U.S – July 5, 2024 – A pickup truck covered with political stickers supporting Donald Trump and Republican party. (Photo by Khairil Azhar Junos on Shutterstock) The Intersection Of Driving And Politics

The pattern was clear. When another driver was driving well, bumper stickers had almost no effect on how participants responded. But when that same driver was driving badly, an opposing party’s bumper sticker made things worse.

Statistical analysis showed that drivers who saw a bad driver with an out-party sticker were significantly more likely to say they would honk their horn and gave substantially colder ratings on the feeling thermometer. Bad drivers with no political affiliation received notably warmer evaluations than bad drivers displaying the opposing party’s message.

Bumper stickers from someone’s own party didn’t reliably soften reactions to bad driving. The effect was one-sided: out-party stickers made aggressive responses more likely, while in-party stickers did little to reduce hostility.

Participants were asked to watch a short simulation of a vehicle cutting them off in traffic. The offending vehicle had either no bumper sticker or a bumper sticker with a neutral “I love my dog” sticker, “Proud Republican” sticker or “Proud Democrat” sticker. (Credit: University of Cincinnati) When Road Rage Becomes Political Rage

These results build on growing research showing how partisan identity shapes behavior in settings that have nothing to do with politics. Previous studies have found that partisans are less willing to sit next to opposing party members at football games, less likely to sell them tickets, and less willing to date them.

Driving adds another layer because cars offer both anonymity and power. Behind the wheel, people feel protected and less inhibited about expressing negative emotions. When partisan identity gets activated during an already frustrating interaction, that protection can lead to more aggressive responses.

Horn honking might seem trivial, but transportation researchers consider it a meaningful measure of hostility that matters for road safety. More aggressive responses to other drivers can escalate minor incidents into dangerous confrontations.

The study involved 895 participants recruited through Amazon Mechanical Turk who watched the simulated driving videos and answered questions about their reactions. The videos were created by a digital artist to look realistic but clearly computer-generated to avoid deceiving participants into thinking they were watching real footage.

Researchers also explored whether race affected these reactions by varying the driver’s license photo shown after each video. In exploratory analysis with White participants, reactions appeared slightly stronger when the bad driver with an out-party sticker was Black rather than White. However, the study was underpowered to draw firm conclusions about these demographic effects, and the researchers emphasized these findings should be considered preliminary rather than definitive.

Polarization’s Everyday Costs

The researchers point to a “negativity bias” in both driving psychology and political psychology. Negative stimuli grab attention more than positive ones, and hostile feelings toward out-groups tend to be stronger than warm feelings toward in-groups.

When these two negativity biases combine during a road interaction, partisan bumper stickers can add fuel to an already frustrating situation.

The study has limitations. Participants self-reported how they would behave rather than being observed in actual driving situations. The sample skewed younger, more educated, more Democratic, and more male than the general population, which is typical for online studies but limits how broadly the findings apply.

The simulated bad driving, while clearly worse than the good driving condition, might not have been severe enough. Most participants in both groups still rated the driving as “driving well,” though three times as many people rated the bad driving as “very poor” compared to the good driving.

Pro-Trump bumper stickers on a car in September 2024. (Photo by Luisa P Oswalt on Shutterstock)

Future research could use driving simulators to measure actual behavior, test different types of vehicles and sticker slogans, and examine how these effects vary across different demographic groups with adequate statistical power.

Still, the findings point to a troubling reality: partisan divisions are no longer contained to explicitly political spaces. They’re shaping how Americans interact during routine daily activities, including something as mundane as driving to work.

Political bumper stickers are everywhere on American roads. If even a fraction of encounters play out like this study suggests, the cumulative effect on road safety and daily stress could be substantial. Every rush hour becomes another opportunity for partisan tensions to surface, turning ordinary traffic into a reminder of political division.

Paper Summary Methodology

Researchers conducted an online survey experiment with 895 participants recruited through Amazon Mechanical Turk. Participants first completed a questionnaire measuring demographics, partisanship, personality traits (particularly agreeableness), authoritarianism, and self-assessed driving quality. They then watched a 28-second computer-generated video simulating dashcam footage. The video showed an orange car either driving well (smooth overtaking and turning) or badly (jerky overtaking, swerving into another lane, and forcing the point-of-view driver to brake hard). The car displayed either no bumper sticker, a neutral “I Love My Dog” sticker, a “Proud Democrat” sticker, or a “Proud Republican” sticker. After the video, participants saw a randomly generated driver’s license showing the other driver’s race (white, Black, or Latinx) and sex (male or female). Participants then rated how likely they would be to honk their horn at the driver on a five-point scale and rated the driver on a feeling thermometer from 0 to 100.

Results

Bumper stickers had minimal effect when drivers were driving well, but out-party stickers significantly increased hostile responses to bad drivers. Participants were more likely to say they would honk and gave lower feeling thermometer ratings to bad drivers with out-party stickers compared to bad drivers with no stickers. The regression analysis showed statistically significant interaction effects between bad driving and out-party stickers for both dependent variables. In-party stickers did not reduce hostile responses to bad driving. The neutral “I Love My Dog” sticker showed effects that fell between no sticker and out-party sticker conditions, though confidence intervals overlapped. In exploratory analysis limited to white participants, reactions appeared slightly stronger when the bad driver with an out-party sticker was Black rather than white, but this difference was not statistically significant. The manipulation check confirmed participants perceived the “bad driving” video as worse than the “good driving” video, though most participants still rated both as generally good driving.

Limitations

The study relied on self-reported behavioral intentions rather than actual driving behavior. The sample was not nationally representative, skewing younger, more educated, more Democratic, and more male than the general population, which is common for Amazon Mechanical Turk samples. The manipulation of driving quality may not have been strong enough, as most participants rated even the “bad driving” as generally good. The study was underpowered to detect effects related to driver demographics, particularly race, making those analyses exploratory rather than conclusive. The experiment used only two specific partisan bumper sticker slogans and one type of vehicle, limiting generalizability to other political messages or vehicle types. The confidence intervals for neutral stickers and out-party stickers overlapped, raising questions about whether partisans react specifically to political stickers or to bumper stickers in general.

Funding and Disclosures

This research was funded by the Mr. & Mrs. F. Claiborne Johnston, Jr. Endowment’s 2021 Junior Faculty Grant Program at James Madison University. The authors declared no conflicts of interest and confirmed no generative AI was used in creating the manuscript. The research was approved by the Institutional Review Boards at Knox College and James Madison University.

Publication Details

Torres, R. S., & Farrer, B. D. “How do drivers react to partisan bumper stickers? Understanding polarization in apolitical settings,” published in Frontiers in Political Science, September 24, 2025. DOI: 10.3389/fpos.2025.1617785