1 - Background and Methods

This report presents general traffic enforcement trends in eleven sites across the United States and compares the roles of different categories of law enforcement agencies in those communities regarding traffic law enforcement.


For many years, increased demand for police services and increased budgetary pressures that occurred in many jurisdictions across the United States strained traffic law enforcement resources. One indication of this is the decrease in the volume of driving while intoxicated (DWI) arrests on a nationwide basis. After peaking at near 2 million per year in the mid-1980's, these arrests have now decreased to about 1.4 million per year. In the late 1980s we examined reasons for changes in DWI enforcement levels in six jurisdictions and found decreases in DWI arrest volume to be attributed to increasing volume of work within police agencies (as indicated by volume of calls for service) in the face of stable staffing levels, changing command emphasis in response to constituent demands in other areas (other drugs, gangs, etc) and officer burn out. Our continuing contacts with police agencies suggested that increased demands and costs have resulted in decreased enforcement of traffic laws in general, even with new interest in traffic issues such as aggressive and distracted driving, but the effect had not been quantified to any extent. Therefore the need for this project was clear. This study is an attempt to objectively quantify trends in traffic law enforcement in a variety of law enforcement agencies across the country.


The general objective of the project was to evaluate any changes in traffic law enforcement trends in selected sites in the United States for the past ten years. Specific objectives were:


To accomplish the objectives, project staff identified appropriate law enforcement agencies (LEAs) which could provide pertinent data. Staff members then collected the data, had discussions with appropriate individuals in the LEAs, analyzed the information and made comparisons between LEAs where appropriate. All of the information is summarized and presented in this report.

Site Selection

Regional diversity was sought during the site selection process. Obviously, the ability and willingness of each LEA to provide data were prime criteria in determining which agencies would participate in this project. A minimum of ten LEAs were to be included in this study, including State Highway Patrols, County Police Departments, City Police Departments and full-service Sheriff Departments.

The following table lists the eleven sites and the law enforcement agencies that were studied during this project. Three of the LEAs are statewide agencies, one is a County agency, three are City police departments and four are full-service Sheriff's Departments.

Table 2: Project Sites, LEAs and Agency Type
State Site LEA Agency Type
CA Statewide California Highway Patrol State
CA San Diego San Diego Police Department City
CO Douglas County Douglas County Sheriff's Office Sheriff
DE Statewide Delaware State Police State
FL Statewide Florida Highway Patrol State
FL Orange County Orange County Sheriff's Office Sheriff
FL Seminole County Seminole County Sheriff's Office Sheriff
IL Palos Heights Palos Heights Police Department City
NC Guilford County Guilford County Sheriff's Dept. Sheriff
TX Austin Austin Police Department City
VA Fairfax County Fairfax County Police Dept. County

The populations of the jurisdictions served by these LEAs range from approximately 12,000 (Palos Heights, Illinois) to 33,145,121 in the State of California. Specific site information is provided in the corresponding chapter devoted to each site.

Data Collection

The data collected during this project emphasized quantitative indicators of activity, which were measured by such dependent variables as citations and citations per licensed driver, and were influenced by factors such as numbers of patrol officers and department budget, among others. However, more subjective information was also gathered through discussions with enforcement personnel (e.g., the implementation of new enforcement policies and special enforcement programs, and the application of new technologies).

Quantitative Data Collection. This portion of the data collection encompassed gathering much of the objectively quantifiable data which was used in the analysis. The project called for gathering fairly detailed data on a number of variables over the preceding 10 years on an annualized basis. In order to enhance analysis possibilities, an endeavor was made to obtain monthly counts of data where appropriate.

Specific categories of data are discussed briefly below:

Discussions with Law Enforcement Officers. At each of the sites, project staff talked with various agency personnel about issues surrounding traffic law enforcement including:

Naturally, the data we collected from the various agencies were in different formats and contained different data elements. We processed the data so that, where possible, they would fit into a data set which allowed the analytic work to be conducted. In the figures throughout this report, solid lines most often represent the data. In many of the figures, a thin, dotted line also appears along with the solid data line. This dotted line is the trend line and designates the general trend of the data displayed.


This report contains 14 chapters. Beginning with Chapter 2, a chapter is devoted to each project site (Chapters 2 - 12). Chapter 13 contains discussions and compares the findings. The final chapter presents our conclusions and recommendations.