Measuring racial and ethnic disparities in traffic enforcement with large-scale telematics data

Abstract

Past studies have found that racial and ethnic minorities are more likely than white drivers to be pulled over by the police for alleged traffic infractions, including a combination of speeding and equipment violations. It has been difficult, though, to measure the extent to which these disparities stem from discriminatory enforcement rather than from differences in offense rates. Here, in the context of speeding enforcement, we address this challenge by leveraging a novel source of telematics data, which include second-by-second driving speed for hundreds of thousands of individuals in 10 major cities across the United States. We find that time spent speeding is approximately uncorrelated with neighborhood demographics, yet, in several cities, officers focused speeding enforcement in small, demographically non-representative areas. In some cities, speeding enforcement was concentrated in predominantly non-white neighborhoods, while, in others, enforcement was concentrated in predominately white neighborhoods. Averaging across the 10 cities we examined, and adjusting for observed speeding behavior, we find that speeding enforcement was moderately more concentrated in non-white neighborhoods. Our results show that current enforcement practices can lead to inequities across race and ethnicity.

Risk scores, label bias, and everything but the kitchen sink

“…For example, Beckett et al (36) found that the geographic concentration of police resources in Seattle led to higher arrest rates for Black individuals delivering drugs compared to white individuals delivering drugswhere the true racial distribution of those delivering drugs was estimated from survey data and ethnographic observations. Similarly, Cai et al (37) found that the issuance of speeding tickets varied across neighborhoods even after adjusting for the true underlying incidence of speeding, as estimated by the movement of mobile phones.…”

The racial composition of road users, traffic citations, and police stops

“…Academic research generally agrees that racial profiling exists and is widespread ( 7 – 10 ), though there may be variation between differently sized police departments ( 9 ). In general, research has supported the “minority threat” hypothesis, which suggests that a greater proportion of minority residents in a city is associated with greater policing activity.…”

“…In general, research has supported the “minority threat” hypothesis, which suggests that a greater proportion of minority residents in a city is associated with greater policing activity. This has resulted in areas with more Black residents experiencing higher ( 8 , 11 ) and growing enforcement rates ( 12 ).…”

“…The Open Policing Project ( 14 ) records 95 million traffic stops across 35 US municipal departments. This data has been used to show that speeding-related stops were not demographically proportionate to the areas in which they occurred ( 8 ).…”