Cars and the Fourth Amendment

By Blair Morris

October 16, 2019

By EMILY A. PRIFOGLE

Review of Policing the Open Road: How Cars Transformed American Freedom, by Sarah A. Seo

Cambridge: Harvard University Press, 2019 


Sarah Seo’s book begins with the tales of two drivers, ninety-nine years apart. In 1916, Captain John Bates and his wife Mary were rumbling down an Arizona road when three police officers fired at the car after shouting at John to stop. One of the shots killed Mary, and as a result, one of the police officers was later convicted of murder. The Arizona court that heard his appeal did not focus on the officers’ right to arrest, but instead on driver’s right to drive, which entitled them, according to Seo, “to proceed on their way without interruption or molestation” (4). This was a remarkable conclusion that is difficult to imagine today in our world of violent traffic stops caught on tape.  

Readers will remember Seo’s tale of a second driver, Sandra Bland, who was arrested in 2015 after being pulled over for failure to use a turn signal. The violent arrest was caught on the officer’s dash camera. She died in jail three days later. No court expounded on her right to drive over the officer’s right to arrest. Or perhaps, readers will not remember the specifics of Bland’s arrest, despite its capture on video and the viral hashtag that followed in the wake of her death because violent car stops of African Americans appear all too often in the twenty-first-century news cycle. Seo’s book is a masterful explanation of why the constitutional landscapes across which these two drivers traveled differed so greatly.  

Policing the Open Road meticulously tracks the law of car stops across the twentieth century and details how motorists, the police, and legal scholars think about policing drivers. Seo argues that when judges redrew the “boundaries of legitimate policing” to permit the discretion police needed to enforce traffic laws against otherwise law-abiding citizens in the early twentieth century, the unintended result was discriminatory policing against people of color decades later. Contrary to familiar histories, Seo suggests, “Fourth Amendment jurisprudence evolved not just to limit police discretion…but also to accommodate it” (17).  

In addition to scrutinizing Supreme Court decisions, Seo explores the files of the ACLU, the NAACP, and the writings of police chiefs, together providing a view of the ground-level stakes of the Supreme Court’s Fourth Amendment decisions. Although those decisions sought to use procedural regulations rather than substantive rights to limit police discretion in the field, a professionalized police force came to “take advantage of the thicket of procedures to exercise their power in discretionary, even discriminatory ways” (20). 

The arc of the history told by Seo begins with the “democratization of policing” that accompanied the mass production of cars in the early twentieth century (7). As the number of cars grew, unsurprisingly, the number of traffic problems and dangerous car accidents also grew. Local governments acted first, but the proliferation of new traffic laws “turned everyone who drove a car into a lawbreaker” (27). In a society moving away from community or neighborhood-based self-regulation, more police surveillance was necessary to ensure that drivers obeyed the law. 

Like those in other occupations in the first decades of the twentieth century, police forces took part in a professionalization movement that prized expertise. At first, monitoring traffic, like monitoring vice, was understood as a distraction from the real work of fighting crimes like theft and murder. It was possible to imagine a world in which policing did not include the oversight of traffic regulations, but not for long. More cars demanded bigger police forces and policing quickly became “an inescapable fact” of our automobile society (88). Plus, as early as the 1920s, most crimes—not just traffic violations—involved a car. During Prohibition, for example, cars provided both cover for rumrunners and a getaway car for moonshiners to elude police officers who were unable to pursue the bootleggers into another jurisdiction. Importantly though, it was not just criminals in cars, upright citizens violated traffic laws—even pedestrian jaywalkers. When everyone violated traffic laws, professionalized enforcement of traffic laws demanded police behave courteously, especially to those citizens who were not accustomed to encounters with police.  

In the modern world of mass standardized cars and professionalized police forces, Seo asks, “how would the Fourth Amendment adapt” (116)? Was a car more like a house (requiring a warrant prior to search) or a person (requiring post-arrest procedures in the event of a warrant exception)? Where would the car fall in the public/private framework? Seo teases apart how cars defied these established categories of Fourth Amendment law—and the persistence of the public/private framework in the legal reasoning of Supreme Court decisions. 

The path set by Carroll v. United States (1925) flows throughout the book. Carroll broke from the categories of public and private by establishing a standard of “individualized determination of reasonableness” (140). From the officer’s point of view, was there “reasonable or probable cause” that a crime was occurring? From the beginning, the problems with the new automobile exception established in Carroll was clear to observers: “What would prevent an unscrupulous and lawless agent from manufacturing ‘reasonable and probable cause’” (140)?  

Seo’s analysis of the cases that followed Carroll illuminates how further interpretations of the reasonableness standard increased the power of police. In conversation with Risa Goluboff’s recent Vagrant Nation, Seo links the history of the rise of cars and modern policing with arguments for stop-and-frisk practices—outside the realm of cars. Terry v. Ohio (1968) relied on Carroll. Changing Fourth Amendment law around car stops in the early twentieth-century resulted in a shift from a question of warrants to a question of reasonableness in late twentieth-century jurisprudence. 

Perhaps the most striking section of the book is the fourth chapter, “It Could Happen to You,” which explores mid-century drivers’ experience of discretionary policing. Mid-century jurists, Seo finds, were concerned about arbitrary policing of “Everyman,” that is, someone who was “white, male, and law abiding” (169, 182). Legal thinkers understood arbitrariness as distinct from discriminatory policing targeting specific groups of people. Nearly everyone in America was a driver, and that meant that Everyman was harmed by arbitrary policing of cars. Although the ACLU received many letters from Everyman detailing indignities experienced during car stops, it is Seo’s use of NAACP letters that reveals the stakes of police discretion. She gives heart-wrenching examples of a well-known fact of American history, that “African Americans were falsely arrested, beaten, or shot” at the hands of police officers who pulled them over at mid-century, and she situates that fact in the broader development of Fourth Amendment law (183). The reasonableness standard had made it “easy for officers to concoct a defense” to routine acts of violence against African Americans (186). 

Drawing on the work of Charles Reich in the 1960s, Seo contrasts the experience of arbitrary policing with the experience of driving. To great effect, Policing the Open Road captures the joy and empowerment that many Americans felt, and still feel, while driving. Reich’s description of going for a drive will be recognizable to many: “We might suddenly veer off our route to ring the front door of a friend’s house, spend a few minutes, and then zoom away. We might stop unexpectedly for jelly doughnuts” (204). Indeed, my own weekend drives along the country roads of southern Indiana look much like Reich’s, including the classic rock on the radio and unexpected stops for ice cream. But even Reich, a well-known and respected legal thinker, and a resolute believer that where he was driving to or from was “nobody’s business,” could not work his way out of a procedural rights framework for limiting discretionary policing (207). He recommended more procedural guidelines to limit discretionary authority rather than substantive rights for driver privacy.  

Reich did not adequately address the problem of race-based police discretion because his leisure drives, like my own, were taken in the comfort of white privilege. Seo uses the 1968 documentary, Black on Black, to demonstrate this point. Cars were about more than the freedom to roam around on Sunday drives. By the 1960s, they had become essential to a more basic experience of freedom: the mobility required to find a job and get to work. That mobility, however, was put in check by the officers in Los Angeles who pulled over African Americans to check for minor infractions concerning tire pressure, brakes, windshield wipers, brake lights, or dimmer switches. The documentary made clear that it was impossible to live in Los Angeles without a car, and therefore it was also impossible to avoid police harassment. Proceduralism protected the Everyman, but not minority motorists. 

Seo carefully marks out, then, how the Due Process Revolution did not begin with Mapp v. Ohio in 1961 but began much earlier when courts were figuring out the law of traffic stops. Proceduralism offered a way to challenge police discretion—but it has been inadequate to achieve justice for everyone. Fourth Amendment jurisprudence by the later decades of the twentieth century became fractured by a proliferation of fact-based constitutional challenges. The legal debate was not about whether there would be discretion, but how closely to manage police discretion. Seo deftly marches through the case law showing the reader how we arrived at a point where it was not “unreasonable” to start with an arrest for a minor traffic violation and end with a search of the entire car (254). 

As she does throughout the book, Seo weaves together doctrinal analysis with on-the-ground implementation. For instance, she assesses a 1980s policing manual that instructed officers on how to turn traffic stops for minor violations into drug convictions. By holding that motive—even racial bias—had no effect on the constitutionality of the reasonableness of police discretion under the Fourth Amendment in Whren v. United States (1996), the Court refused to recognize that discretionary policing had enabled the racial profiling implicitly instructed in the manual. A racially profiled pretextual stop had been an official tactic of the War on Drugs for over a decade when Whren held such stops constitutional.  

In his opinion for the court in Whren, Justice Scalia concluded that “the constitutional basis for objecting to intentionally discriminatory application of laws is the Equal Protection Clause, not the Fourth Amendment.” Seo argues that it matters that discriminatory policing is currently only remedied through equal protection law rather than considered unreasonable under the Fourth Amendment. It is not, she writes, just that police use pretextual policing to treat people of color differently, it is that police “have that much discretionary power at all” (p. 266). If Everyman experienced police discretion while behind the wheel today in the same ways that people of color do, Seo suspects the Court’s interpretation of the Fourth Amendment might change.  

Seo’s book leaves the reader wanting more—not because the book is incomplete, but because it opens new ways of thinking about cars and law. Given the centrality of cars to twentieth-century Fourth Amendment jurisprudence, I found myself hungry for more on-the-ground examples beyond the NAACP complaints or police manuals found in the book. Seo identifies a significant “distance separating the nine justices sitting at the top of the American judicial system and the judges in county seats and municipal courts,” reflecting “the disconnect between the ideals of case-by-case adjudication and its implementation” (247). Since policing is an inherently local function, I hope Seo’s work inspires more historical examinations of that disconnect between adjudication and implementation of policing in the automobile age in specific localities. We still need a better picture of what day-to-day policing via cars looks like given variation across region and community size.  

Unsurprisingly, as someone who thinks a lot about law and space, I was intrigued by the sister threads of modernization and urbanization in the book, especially in the earlier chapters. Cars went hand in hand with a changing American landscape of more cities and even more suburbs. Readers will find Herbert Hoover announce in 1924 that “Locality has been annihilated, distance has been folded up into a pocket piece” (39). Hoover’s words aptly summarized the car’s ability to alter space and the experience of time. What he meant was that before cars, a traveler would measure the distance to her destination by time, not physical distance. A town twenty miles away on a direct train line might be reachable in a few hours, but a town fifteen miles away, not on a direct train line, might take much longer either by horse or by train with a connection. Cars made the relationship between physical distance and time more direct. No longer bound by railroad timetables or the distance one could walk or ride a horse in a day, Americans were free to travel where they wanted, when they wanted.  

Eventually, the United States became what historian Christopher Wells has called “Car Country,” denoting places where car dependence is woven into the American landscape. Wells summarized most scholarship on Car County as utilizing two narratives—one about cars embodying core American values in the liberating, empowering, and democratic experiences cars offer, and one about the environmental devastation wrought by more cars, more pavement, and more fossil fuels. Seo opens an important new narrative to explore—the way cars altered the spatial experience of law: “More pavement in turn led to more cars, which led to more drivers, which led to more police” (179). Americans traveled through a landscape suffused with regulations at every turn, and law enforcement practices shaped the experience of navigating that landscape. 

Seo delineates the implications for discretionary policing and the Fourth Amendment, but there is still more to explore about how, as legal thinkers like Harvard Law School’s Roscoe Pound observed, cars disrupted older small-town patterns of self-regulation in America’s new cities. Cars and modern policing appeared in the same moment as urbanization. Seo recognized that when “flocks of the upright moved to twentieth-century towns and cities, laws, especially criminal laws, replaced conscience as a tool of governance” and that many, like Pound, “recognized [that] law enforcement was much harder in urban settings” (47). But of course, the changes in policing that cars wrought also impacted those outside the city in rural villages and suburbs, and I look forward to those who build on Seo’s foundational research to explore how cars shaped law enforcement and surveillance in those places specifically. I am curious, for example, how expanded police discretion during traffic stops is affecting efforts to control the opioid epidemic in rural communities, where cars remain necessities. 

Cars are ubiquitous in twentieth-century American histories. Policing the Open Road is first and foremost a work of legal history, but just as it contributes to scholarship on today’s Fourth Amendment, it adds an important perspective to other fields of history grappling with the rise of automobility, most notably the fields of environmental history, urban history, and the history of science and technology. Even labor historians might rethink anew the role of cars in the context of labor rights. Colleen O’Neill and Julie M. Weise, for example, have noted how cars were crucial to the agency of migrant agricultural workers. Cars were so essential to the ability to assert control over working conditions that migrant workers occasionally included a photo of the family car in family photo albums.  

It is also exciting to think about centering the car in histories of social movements more broadly—consider the well-known example of cars that shuttled boycotters around town during the Montgomery Bus Boycott during the Civil Rights Movement and the use of discretionary policing to curb the carpool’s impact. Seo tells an important story about how mass automobility drove changes in Fourth Amendment jurisprudence throughout the twentieth century, but also demonstrates exciting possibilities for legal history and legal scholarship when cars are centered as actors, enabling a rethinking of traditional legal narratives through the lens of changing technology. 

Policing the Open Road is a beautifully written book that moves seamlessly from doctrinal analysis to exploration of themes in popular culture, like Jay-Z’s song, “99 Problems.” The legal history will be of interest to criminal law scholars and historians of policing. Yet, Seo is also particularly adept at clearly explaining legal concepts for those not so versed in Fourth Amendment doctrine, and the book is readily accessible to those more generally curious about how we came to live in a Driving While Black—even Parking While Black—society. Her history of cars and the Fourth Amendment also provides crucial context for considering the public and private nature of new searchable private property like cell phones connected to the public information superhighway. Seo has convinced me that even if the Fourth Amendment jurisprudence solved one generation’s problem, we need to start “defining freedom anew” for this generation (275). 

Posted on 2 October 2019


EMILY PRIFOGLE is a Faculty Fellow at the University of Michigan Law School and is currently working on a book about the legal history of rural communities in the twentieth century.


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About Blair Morris