Traffic Enforcement and Control Research Paper

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Police agencies engage in a variety of traffic services. These efforts are designed to encourage motorists to obey traffic laws and regulations through a variety of methods. It is hoped that such compliance will maximize traffic efficiency and obedience of the law while minimizing traffic disruptions and accidents. The traffic services provided by state, county, municipal, and special jurisdiction law enforcement agencies are frequently associated with a range of organizational objectives. Though enforcement of traffic laws is a major objective, traffic services are also provided with the intention of minimizing injuries and property damage due to traffic accidents, determining facts when accidents and collisions have occurred (both to determine fault and to provide data for accident prevention efforts), assisting accident victims, obtaining compliance with traffic laws, and maximizing efficient use of congested roadways (Sheehe 1971). Traffic services include efforts to enforce traffic laws, regulate and direct the flow of traffic, minimize traffic accidents (both volume and severity), and efficiently respond to accidents when they do occur.

After providing generalized patrol services, traffic enforcement is one of the major ancillary tasks undertaken by local police agencies (Walker 1992). Citizens report that traffic stops are the most common situation in which they have contact with the police (Durose et al. 2007). Data suggest that nearly 10 % of citizen calls to the police relate with a traffic problem of some sort (most typically reporting traffic accidents but also to complain about traffic violations or traffic flow problems) (Scott 1981). Other studies have found that nearly one-quarter of patrol officer time is spent on traffic enforcement activities (Greene and Klockars 1991). Traffic services and enforcement serve a crucial secondary purpose for police officers and organizations. For officers, traffic enforcement may have less to do with the enforcement of traffic laws and more to do with providing an officer legal grounds to look for more serious violations (Schafer and Mastrofski 2005). Though traffic services may not seem glamorous and are often downplayed in media portrayals of policing, they represent a range of tasks that are central to policing, both in terms of their frequency and importance.

Fundamentals

Agencies vary considerably in the extent to which traffic services are a specialized or generalized function (Walker 1992). Specialized traffic services assign traffic enforcement, traffic regulation, and/or traffic accident investigation to specific officers who are usually freed from other policing duties, such as responding to emergency calls for service. This situation is increasingly common as the size of an agency increases and specialization of all types begins to be more evident within the organization’s structure. Specialization of any policing task is presumed to increase the efficient use of personnel resources and to free general patrol officers from time-consuming tasks not directly related with crime control. The presence of a specialized traffic service function does not mean general patrol officers will not engage in any traffic-related activities; rather, having a specialized function would be expected to reduce the amount of time general patrol officers spend on these activities, at least during the times when specialized officers are working.

Generalized traffic services responsibilities occur when all officers are expected to routinely engage in traffic enforcement, traffic regulation, and accident investigation. This is more likely to be noted in medium and small agencies, where specialization is less common or the extent of specialization is modest. For example, in a 30-officer department, 1 or 2 officers working the day shift might be given responsibility for traffic services. During other times of the day, general patrol officers would be expected to provide those services. There may be additional variation in how agencies assign traffic service duties, even where a specialized unit is present (i.e., a traffic unit might handle traffic control and traffic accident investigation, while all officers are expected to engage in routine traffic enforcement). In agencies that place a heavy emphasis on traffic enforcement, such as state police and highway patrol, traffic services may be a generalized responsibility even when the agency is quite large.

Though contemporary evidence is sparse, some research suggests agencies produce a higher volume of traffic enforcement activity when traffic is a specialized function (Gardiner 1969). A variety of reasons could explain this situation. In larger agencies, general patrol officers may not have the time to engage in traffic services because of a high volume of calls for service. General patrol officers may also lack some resources in support of traffic enforcement; for example, radar units might not be installed in vehicles used by general patrol officers and/or not all officers may be certified (if required by the state) in the use of radar equipment. There might also be an absence of a culture of traffic services in a given jurisdiction; traffic services might be viewed as a “soft” assignment, something an officer does when she/he wants to work the day shift or escape the “grind” of routine patrol.

Traffic Enforcement

When most citizens think about police efforts centering on traffic services, it is likely that traffic enforcement is the first activity that comes to mind. Traffic enforcement and regulation efforts represent a curious convergence of circumstances in the understanding of police organizations and discretionary choices of police officers (Lundman 1979). Organizations have various incentives to regulating the volume of enforcement efforts by personnel, including the desire to ensure public safety, to control crime, and to respond to public demands for action on select offenses (i.e., drunk driving) (Mastrofski et al. 1987). Within those circumstances, however, traffic services remain a highly discretionary activity for officers and, at times, a low visibility activity (Brown 1981). Though officers may have to meet certain overall expectations for their production and provision of various traffic services, they often enjoy considerable latitude (sometimes granted by state law) to decide when to invoke the law. Situations where officers show such leniency are rarely captured in existing police data systems and are rarely known to anyone aside from the officer and the motorist.

Traffic enforcement activities can be the source of tension, danger, and inconsistencies for the police and the public. Citizens may resent being stopped and subject to extra attention by the police, even if a citation is not issued. It should be noted, however, that the overwhelming majority of citizens stopped by the police report that they believe the police had legitimate reason for initiating that contact (Durose et al. 2007). Officers killed or injured on the job are often involved in traffic service activities. Around 13 % of police fatalities and nearly 10 % of assaults on the police occur while officers are engaged in traffic stops (Lichtenberg and Smith 2001). For decades researchers have noted inconsistencies in the traffic enforcement actions of agencies. James Q. Wilson first noted this variation in his classic text Varieties of Police Behavior (1968), observing that agencies of similar size and jurisdiction often vary considerably in the rates with which they engage in traffic stops and, when stops are made, take formal enforcement action by issuing a citation. Some agencies demonstrate low levels of enforcement and/or respond to traffic violations with verbal warnings, while other agencies are quite actively involved in traffic enforcement, including the issuance of a high rate of citations (Gardiner 1969; Mastrofski et al. 1987; Wilson 1968). This may contribute to citizen frustration, as it is not always clear when and where a traffic offense will invoke a formal police response.

Explaining Variation In Traffic Enforcement

Variation in the frequency of engaging in traffic stops and issuing traffic citations can be explained by a number of potential factors. In large part, such variation is likely a reflection of differing department objectives and community expectations. Though rarely discussed, in many communities traffic enforcement often contributes appreciably to city and county coffers (Radelet and Carter 1994). When a traffic citation is issued and the motorist is subsequently ordered to pay a fine, the issuing agency is not the direct recipient of those funds. However, the overriding governmental unit (the city or county) often does receive a proportion of the fine paid by the motorist. Particularly in difficult economic times, governmental units can become dependent on a certain level of resources. This might not pressure an officer to issue a citation on any given traffic stop, but it might result in implicit pressure on an agency to maintain or even increase the volume of citations issued over time. Some agencies might try to limit local opposition to heavy traffic enforcement by targeting efforts in areas where out-of-town drivers are more likely to be caught committing a violation (i.e., encouraging officers to “run radar” on a state highway).

High levels of traffic stops and/or traffic citations can also be a reflection of myriad noneconomic pressures. For example, a community may be calling upon the police to increase traffic enforcement, particularly for select offenses (i.e., speeding) or in specific areas (i.e., near schools or commercial area). Top agency administrators may request officers to modify their behavior in specific ways, such as requesting that officers increase the number of traffic stops or show more restraint in issuing traffic citations. Calls for increased traffic stops or enforcement may reflect a belief that such actions will enhance public safety, though evidence demonstrating a clear ability of the police to achieve that outcome is mixed (see below). Leaders may also formally or informally ask officers to increase traffic enforcement because traffic stops are one way agencies can document that officers are working. Agencies will be reluctant to refer to these expectations as “quotas,” but it is not uncommon for agencies to establish “productivity standards” (or similar expectations) based in part on the frequency of traffic stops and/or citations for each officer. Given the limit direct supervision most officers receive, a traffic-related productivity standard is one way supervisors and agency leaders can ensure that officers are being vigilant in engaging in work-related activities while on routine patrol (Walker 1992). Agencies cannot easily assign officers to make a given traffic stop (as an agency might assign an officer to handle a specific complaint or take a specific report), but expecting officers to document a select number of traffic stops per shift or issue a certain number of citations or warnings per month is thought to demonstrate a minimal level of vigilance on the part of each officer. Such expectations are predicated on the assumption that officers can routinely identify legal cause to stop motorists for violations or other pretense.

The volume and nature of traffic enforcement behavior by officers has been noted to vary not only across agencies, as discussed earlier, but also across officers. Within the cultural and organizational expectations regarding traffic enforcement, officers may opt to merely meet standards or choose to exceed organizational expectations (Schafer and Mastrofski 2005). This reflects an established reality in policing research that demonstrates that officers vary in when, where, and how they use discretion in performing their work-related duties (Brown 1981). In the context of traffic enforcement, some officers will have a strong inclination to engage in a high rate of traffic stops and issue a large number of citations. This vigor may be due to the belief that such activities will either ensure greater control in the community or because of a desire to remain active during unassigned duty time. Other officers will engage in these activities with enough frequency and vigor to satisfy the expectations of their supervisors and organization, but will not go substantially beyond that threshold. Still other officers may engage in a high rate of traffic stops while issuing few citations. For these officers, traffic stops have instrumental value; they allow officers to initiate contact with citizens to investigate suspicious or unusual circumstances with the ultimate objective of detecting criminal conduct. Though organizations and communities can exert some influence, individual officers maintain some latitude to decide how they prioritize traffic enforcement efforts in the performance of their duties.

Nonenforcement Traffic Services

In addition to enforcing the law, police officers and organizations engage in other traffic services aimed at regulating the flow of traffic and responding to traffic accidents. Nonenforcement traffic services can also generate tension and dangers for the police. Directing traffic is a common policing activity, both in special circumstances (i.e., at a special event or during the aftermath of a traffic accident) and as a routine assignment (i.e., directing traffic near a school or at busy urban intersections). Motorists may be frustrated with the perceived inflexibility of officers or delayed movement of traffic. A driver may feel ill will toward the police because they are not allowed to take their preferred route. Officers may become frustrated while working long assignments in full uniform, with full exposure to the elements. Citizens may perceive the police are exacerbating traffic problems, and officers may perceive shortcomings in the cognitive and driving abilities of the driving public, though neither of these outcomes will be universally present.

In addition to enforcing motor vehicle laws and regulating the flow of traffic, an important traffic service function performed by the police is the investigation of accidents. Traffic crashes are a leading cause of death (causing more annual deaths than crime) and generate a tremendous economic impact. As a matter of public safety, officers are tasked with responding to traffic accidents in order to facilitate medical care, regulate the flow of traffic while a matter is resolved (to minimize the likelihood of a secondary accident occurring), coordinate the removal of disabled vehicles, and assist the involved parties. Officers will generally question the motorists and any witnesses, examine the vehicles involved, note the position of vehicles on the roadway, and in some cases take photographs, collect physical evidence, or otherwise examine and record the existing evidence (i.e., skid marks). These investigative efforts are intended to support officers in determining how an accident occurred, what took place, and, where relevant, how to assign blame for the accident. The latter point becomes relevant if it is determined that enforcement actions are needed but also to support decisions of responsibility relevant to insurance and other financial and legal claims that may arise as a result of an accident.

Data generated by police accident investigations and reports can also be used to support traffic safety enhancement efforts. On a local level, agencies use data to identify high-risk intersections. This information might shape traffic regulation decisions within a jurisdiction, such as changing the pattern of a traffic light or installing some form of traffic regulation technology. Local data might further be used as a rationale for increasing enforcement efforts in a particular area. On a large scale, traffic data might be used to inform traffic laws or policies. Knowing who is often involved in accidents, when those accidents occur, and the nature of those accidents can all provide support for changes. For example, a state might opt to lower speed limits on certain road, restrict select driver behavior (i.e., texting while driving), or modify who is allowed to operate certain types of vehicles (i.e., allowing additional testing to authorize someone to operate a motorcycle). Though large volumes of data amassed by street-level officers often are used to justify these policy changes, it is not always clear those changes achieve the intended outcomes (typically a reduction in the frequency and severity of traffic accidents).

The Effectiveness Of Traffic Services

The efficacy of traffic services and enforcement is subject to some debate. The relationship between police enforcement behaviors and actual reductions in crime, traffic violations, and traffic accidents has not been conclusively established. Steven Rock (1989) evaluated a traffic enforcement program that was implemented to reduce traffic accidents in Batavia, Illinois. Rock’s analysis suggested that accident rates did decline in Batavia, though perhaps not for the expected reason. He attributed at least some of the decline to improved accident investigations conducted by Batavia officers, which in turn helped generate data that allowed the city to redesign intersections where a high rate of traffic accidents occurred. Thus, the efforts of the Batavia police did not directly influence the behavior and actions of motorists. Instead, the effect was indirect; the police influenced traffic engineering and roadway design, which influenced driver behavior and resulted in fewer accidents.

It remains unclear how police should direct efforts to reduce traffic violations and associated problems (i.e., the volume and severity of accidents) (Scott 2001). Though the limited available research has tended to focus on reducing traffic issues through the use of enforcement, other mechanisms might be presumed to achieve the same outcome. Citizens can be educated using signage, media alerts, and the distribution of literature. Potential violators might be deterred through visible police presence and/or a heightened volume of traffic stops, even if enforcement (i.e., traffic citations) is not an outcome of those efforts. Roadways might also be engineered to improve the flow of traffic through high-accident areas and/or by building design elements (i.e., “traffic calming” features such as narrowing roadways, intentionally creating curving roadways, or creating speed humps) into roadways to make violations less likely. Tactics deemed to be less effective in reducing traffic violations and accidents include decreasing speed limits, increasing fines and penalties, and reengineering vehicles (i.e., the use of speed governors) (Scott 2001).

Traffic enforcement is a common element in police efforts to reduce crime and violence (McGarrell et al. 2002). In such instances, traffic stops are not used with the explicit intension of reducing traffic violations. Instead, traffic stops are used to provide lawful pretext for officers to stop vehicles, either in general or when the vehicle is deemed to be “suspicious.” Officers are likely focused more on identifying motorists, running want/warrant checks on vehicles and their occupants, and obtaining lawful authority to search vehicles and their occupants. Such authority might be obtained by a citizen granting consent, when officers determine they have lawful authority to conduct a Terry search, or when other legal circumstances are present (i.e., contraband observed in plain view, incident to an arrest, or incident to a vehicle being towed). When the police engage in this type of traffic enforcement, the objective is usually to reduce crime and disorder, not to influence or regulate driving behavior. The traffic stop becomes the legal means to achieve some other end objective.

Only a few quality studies have attempted to assess whether aggressive police enforcement of traffic laws can achieve a meaningful reduction in crime rates. Early studies of this phenomenon supported that areas with higher levels of traffic enforcement had lower rates of robberies (Sampson and Cohen 1988; Wilson and Boland 1978). In contrast, Weiss and Freels (1996) found that increasing traffic enforcement in high-crime areas did not influence robberies or auto thefts nor did it increase the frequency of felony arrests, in Dayton, Ohio. Their analysis also could not support that higher enforcement resulted in more arrests for drug crimes, weapons crimes, or DUI.

Despite the common presumption that increasing the vigor of traffic enforcement will engender ill will toward the police, some studies have found the opposite to be true. This situation may be a function of the traffic enforcement methods used by the police. If the police seek to influence the behavior of the driving public, they might do so by increasing the issuance of traffic citations. If the police seek to influence crime and disorder, they might increase the frequency and investigative rigor of traffic stops, without actually issuing more citations. In such circumstances, traffic stops are not the end objective but rather a means to that objective. Research has found citizen support for more aggressive traffic enforcement actions by the police when those actions are undertaken in the name of community safety and order. This finding is tempered to some extent by the reaffirmation that while aggressive strategies might enhance citizen perceptions of the police, they might achieve that outcome without actually influencing crime (Chermak et al. 2001; Weiss and Freels 1996). In other words, while citizens might support aggressive traffic enforcement efforts initiated in the name of reducing crime, those efforts have not conclusively been shown to influence crime rates.

Key Controversies

Traffic services have been a contentious aspect of police-community relations, since police agencies first assumed responsibility for investigating accidents, enforcing motor vehicle laws, and regulating the flow and movement of traffic. Citizens presumably recognize the need for, and value of, traffic enforcement and regulation by the police. Citizens may not, however, appreciate being the specific recipient of such police attention and intervention (Lundman 1979). A motorist might question why an officer is “hassling” them for failing to completely stop at a stop sign, instead of addressing “real crime” within the community. Despite the presumption that aggressive traffic enforcement efforts will engender citizen ill will toward the police, studies have not always found that to be the case. An aggressive enforcement strategy used by the Indianapolis Police Department was implemented as a means of targeting select high-crime neighborhoods. Citizens in these neighborhoods were found to be supportive of the police department’s efforts (Chermak et al. 2001), though it is worth noting that officers were instructed not to simply conduct more traffic stops but to engage in more targeted enforcement efforts and to conduct more thorough contacts with motorists they stopped.

Corruption

A number of investigations into police corruption have involved issues related with traffic services (see The Knapp Commission Report on Police Corruption 1972). This problem has included officers accepting bribes to not issue citations, police personnel being paid to “fix” traffic citations and parking tickets, police soliciting payment for providing favorable traffic-related services, and companies paying police officials for favorable consideration (i.e., tow truck companies paying to be called more often when citizens needed motor vehicle assistance). Across the country, agencies of all sizes and types have allegedly been involved in such scandals. The problem appears isolated to very small numbers of officers and non-sworn personnel but demonstrates the financial motivations citizens may have to avoid legal sanctions or secure more favorable treatment with traffic-related matters.

Racial Profiling

Traffic enforcement behavior reached a new level of scrutiny in the mid-1990s with the emergence of concerns over racial profiling (also referred to as “Driving While Black” and “Driving While Brown,” among other labels). Though the practice of racial profiling is often seen to have deep roots in the dynamics of American criminal justice, this behavior achieved a more tacit level in the 1980s when the Drug Enforcement Administration (DEA) began to train local law enforcement personnel under the Operation Pipeline program (Buerger and Farrell 2002). Operation Pipeline was predicated on the belief that drug traffickers brought their goods into major port cities using various methods of bulk transportation. From these ports, drugs were distributed throughout the country using couriers who normally used cars to transport their deliveries. The DEA developed a “profile” of the behaviors and other characteristics of drug couriers, including that drivers were often members of minority groups. Though not an explicit endorsement of using race as a factor in deciding whom to stop, Operation Pipeline is often considered to have legitimized what some view as a long-standing practice of incorporating race into police enforcement decisions and practices.

Racial profiling received considerable attention beginning in the 1990s as a number of court cases and media expose´s highlighted disparities in the characteristics of citizens stopped and searched by various departments (Weitzer and Tuch 2006). Prominent among these anecdotes was State of New Jersey v. Pedro Soto, et al. (1996), a court decision that incorporated statistical analysis of behavior exhibited by officers patrolling the New Jersey Turnpike. In particular, a rolling survey of turnpike users and violators found that African American motorists accounted for approximately 15 % of drivers on the turnpike, but accounted for 46 % of violators stopped by police on that roadway. In the first decade of the new millennium, dozens of states created laws regarding racial profiling, and thousands of agencies began collecting data regarding traffic stops in their jurisdictions. Some of the latter efforts were voluntary, while many others were compulsory under state law.

The net result of these laws and data collection efforts remains largely unclear. A wide variety of reports and studies were published in the 2000s seeking to examine whether and how driver characteristics influenced police discretion in traffic stops. Many of these studies were based on data that suffered from a range of limitations and often data were from a single agency and/or a relatively short period of time, making conclusions tenuous. The majority of studies lacked data of sufficient validity to help determine whether minority motorists were more likely to be stopped when compared with nonminority motorists. A few studies suggested that young, male, and minority drivers were more likely to commit more serious traffic violations, which could explain at least some disparities in patterns of who the police stop for traffic offenses (Lundman and Kowalski 2009). The studies generally did suggest minority drivers (especially those who were young and male) were more likely to be searched when stopped by the police, though many datasets did not allow researchers to clearly control for the reason a search was conducted. It was often noted that minority drivers were less likely to be found in possession of contraband when searched, though many studies did not include data on the specific type and quantity of illicit materials and goods. The net result is that racial profiling clearly remains a matter of concern to the public, politicians, and police officials, but the available data provide a very incomplete picture of the extent to which this problem exists and, if so, how profiling actually manifests itself across the range of choices officers make during traffic stops.

Technology-Assisted Traffic Enforcement

The introduction of technology-assisted traffic enforcement efforts has also become a controversial practice. Communities have used video-capture technology and other applications to detect violations and automate the issuance of citations for offenses such as running red lights and stop signs, as well as speeding. Often these systems operate in a “passive” manner without the real-time presence of an officer and the use of a traffic stop. The camera/radar system detects and records the violation, along with the identity of the offending vehicle. The registered owner(s) of the vehicle often receives a citation by mail with some documentation of the offenses in question. In many communities, the expense of installing, maintaining, and operating these systems has been assumed by a private entity. A jurisdiction allows a private corporation to place enforcement devices in the community; that corporation receives a portion of the revenue generated by operating the device. The privatized nature of enforcement and the high revenues automated systems can generate have made the use of technology-assisted devices quite controversial. At times these systems are seen being more focused on generating revenue and profits than actually improving public safety.

Future Directions

Traffic services remain an integral part of modern policing. Traffic regulation and enforcement consume a large proportion of uniformed policing resources and attention. Traffic stops are the most common venue in which the police and public interact; they also provide important pretext to justify police-citizen contacts when authorities are primarily interested in identifying and intervening in more serious criminal matters. These situations are not likely to change in the immediate future.

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