Spatial Distribution of Illegally Parked Bicycles in Central Sendai City

Abstract

This study examines the number,parking conditions,and spatial distribution of illegally parked bicycles in central Sendai City. Illegally parked bicycles meeting any of the following conditions were classified as high-risk cases,as they could obstruct traffic and pose safety risks:obstructing tactile paving,blocking entrances or exits to facilities,protruding onto roadways,reducing the effective sidewalk width to less than 1 m,or rendering sidewalks impassable. A field survey conducted on the afternoon of July 1,2025,recorded a total of 754 illegally parked bicycles,including 186 high-risk cases. Analysis using HDBSCAN and spatial scan statistics showed that although areas east and west of JR Sendai Station had a high volume of illegally parked bicycles,the proportion of high-risk cases was relatively low. Areas with both a high density and a high proportion of high-risk cases were found to be located relatively far from municipal bicycle parking facilities.