Riding an e-scooter at nighttime is more dangerous than at daytime

With rapidly increasing e-scooter usage in the United States [1], a growing number of studies aim to understand the safety aspect of these emerging modes. The existing literature has a limited understanding of time-of-day and seasonal patterns of e-scooter crashes. While many e-scooter safety policies are based on the number of crashes [2, 3], accounting for exposure provides a measure of risk to inform effective preventive strategies [4]. This study focuses on motor-vehicle involved crashes since they constitute the most severe and fatal injuries. We compared daytime and nighttime motor-vehicle involved e-scooter crashes and combined them with micromobility trip data to generate exposure variables and estimate crash risk. The key research question of this paper is as follows: 1. Are crashes or crash rates disproportionately higher at night than in the day? [From: Introduction