Can Enhanced Street Lighting Improve Public Safety at Scale? 

Abstract

Street lighting is often believed to influence street crime, but most prior studies have examined small-scale interventions in limited areas. The effect of large-scale lighting enhancements on public safety remains uncertain. This study evaluates the impact of Philadelphia’s citywide rollout of enhanced street lighting, which began in August 2023. Over 10 months, 34,374 streetlights were upgraded across 13,275 street segments, converting roughly one-third of the city's street segments to new LED fixtures that provide clearer and more even illumination. We assess the effect of these upgrades on total crime, violent crime, property crime, and nuisance crime. Results show a 15% decline in outdoor nighttime street crimes and a 21% reduction in outdoor nighttime gun violence following the streetlight upgrades. The upgrades may account for approximately 5% of the citywide reduction in gun violence during this period, or about one sixth of the 31% citywide decline. Qualitative data further suggests that residents' perceptions of safety and neighborhood vitality improved following the installation of new streetlights. Our study demonstrates that large-scale streetlight upgrades can lead to significant reductions in crime rates across urban areas, supporting the use of energy-efficient LED lighting as a crime reduction strategy. These findings suggest that other cities should consider similar lighting interventions as part of their crime prevention efforts. Further research is needed to explore the impact of enhanced streetlight interventions on other types of crime and to determine whether the crime-reduction benefits are sustained when these upgrades are implemented across the entire City of Philadelphia for extended periods.

Keywords: street lights, place-based interventions, displacement, gun violence, crime

JEL Classification: H40, H7, I1, K42