Methodology
To determine the relationship between traffic incidents and police officers by state, the data and research team at Insurify, an auto insurance quote comparison platform, conducted a correlational study analyzing the density of police officers, frequency of traffic fatalities, and rate of traffic violations by state.
The density of police officers by state, defined as the proportion of police officers in that state in comparison to licensed drivers, was calculated using data published by the Federal Bureau of Investigation (FBI) and the Bureau of Transportation Statistics. Law enforcement data were gathered from the FBI’s latest Uniform Crime Reporting statistics, which list the number of police officers in each state. These numbers were compared against the most recent driver data released by the Bureau of Transportation Statistics, which detail the number of licensed drivers in each state, yielding the density of police officers by state.
Infraction rates by state were calculated using data from Insurify’s database of over 2 million insurance applications. Drivers disclose personal and vehicle information in addition to driving history, including past accidents and driving infractions. Infractions were sorted into seven categories: license-based moving violations, insurance-based moving violations, speeding violations, signal violations, passing violations, DUIs, and reckless driving violations. For each state, Insurify’s data scientists calculated the proportion of drivers with these violations on their record. Infraction rates by state were compared with the density of police officers by state, to determine any correlation between the two.
The latest state-based traffic fatality statistics on rates of traffic deaths per licensed driver and per million miles traveled were gathered from the State Traffic Data report, released by the National Highway Traffic Safety Administration (NHTSA). Traffic fatality rates were also compared with the density of police officers by state and with statewide infraction rates, to determine any relationship between the density of law enforcement officers, the rate at which drivers are charged with driving offenses, and traffic safety outcomes.
Does road policing keep drivers safe?
In an analysis examining the relationship between police officer density, enforcement rate for driving offenses, and traffic fatalities, no significant relationship was found between police presence and driver safety.