Congestion and environmental impacts of short car trip replacement with micromobility modes

Transportation is a basic social need, but most trips are done by private vehicles, which is not environmentally sustainable with growing urban populations. Micromobility (e.g., shared bikes) represents a significant opportunity to replace short private vehicles trips (0–3 miles) and reduce transportation sector emissions. This paper uses Seattle as a case study and estimates that up to 18% of short car trips could be replaced by micromobility. A static traffic assignment model is developed to simulate and compare the results of peak hour traffic under a base case scenario (2014 traffic conditions) to scenarios where a portion of short car trips are substituted by micromobility. Results indicate that micromobility could reduce congestion on heavily congested corridors and wide-scale bike lane deployment can maximize congestion benefits, but the impacts to energy use and emissions are disproportionately low and other measures (e.g., vehicle electrification) are needed to meet climate change emissions targets.