person crossing; traverser
Refers to a person who crosses something, typically a road, street, or other area. Often used in traffic or safety contexts.
Pedestrians, please cross at the crosswalk.
There are many people crossing this road, so careful driving is required.
歩行者 is a general pedestrian, while 横断者 specifically emphasizes the act of crossing.
Compound of 横断 (crossing) and 者 (person).