The objective of this study was to investigate whether an artificial optic flow created by dot motion guides attention in a driving scene. To achieve safe driving, it is essential to understand the characteristics of human visual information processing as well as to provide appropriate support for drivers. Past research has demonstrated that expanding optic flow guides visual attention to the focus of expansion. Optic flow is an attractive candidate for use as a cue to direct drivers' attention toward the significant information. The question addressed concerns whether an artificial optic flow can successfully guide attention even in a traffic situation involving the optic flow that naturally occurs while driving. We developed a visual search paradigm embedded in a video of a driving scene. Participants first observed an optic flow motion pattern superimposed on the video for brief period; next, when the optic flow and video ceased, they searched a static display for a target among multiple distractors. The target detection was faster when a target's locus coincided with the implied focus of expansion from the preceding optic flow (vs. other loci). The artificial optic flow guides attention and facilitates searching objects at the focus of expansion even when the optic flow was superimposed on a driving scene. Optic flow can be an effective cue for guiding drivers' attention in a traffic situation. This finding contributes to the understanding of visual attention in moving space and helps develop technology for traffic safety.