Abstract:While micromobility services (e.g., bikeshare, e-bike share, e-scooter share) hold great potential for providing clean travel, estimating the effects of those services on vehicle miles traveled and reducing greenhouse gases is challenging. To addresssome of the challenges, this studyexaminedsurvey,micromobility,and transit data collected from 2017 to 2021inapproximately 20 U.S. cities.Micromobility fleet utilization ranged widelyfrom 0.7 to 12 trips per vehicle per day,andthe average trip distance was0.8 to 3.6 miles. The median (range) rates at which micromobility trips substituted for other modes were 41% (16–71%)for car trips, 36% (5–48%) for walking, and 8% (2–35%) for transit, 5% (2–42%) for no trip.In most cities, the mean actual trip distance wasapproximately 1.5 to 2 times longer than the mean distance of aline connecting origin to destination. There was a weak and unclear connection between micromobilityuse andtransit use that requires further study to more clearly delineate, butmicromobility use had a stronger positive relationship to nearby rail use than to nearby bus use in cities withrail and busservice.The COVID-19 pandemic led to more moderate declinesin docked than in dockless bike-share systems.Metrics that would enable better assessment of the impacts of micromobility arevehicle miles traveled and emissions of micromobility fleets and their service vehicles, and miles and percentage of micromobility trips that connect to transit or substitute for car trips.

Key words: micromobility, sustainable transportation, public transit, travel behavior, mode choice, performance metrics, COVID-19