This study is considered to be important from the perspective of preventive medicine, since the fact that traffic crashes were related to subcortical leukoaraiosis (SLA) revealed by MRI even in its asymptomatic stage, suggested that early intervention of SLA may help reducing car crashes. However, since the authors investigated the relationship between leukoaraioses (LA) and previous traffic crashes in a retrospective manner, so the possibility of LA being triggered, or affected by the crash itself could not be eliminated. To elucidate this issue, subjects with LA should be followed longitudinally, in a prospective study design. In spite of this limitation, however, it remains important considering taking some countermeasures for subjects with LA not to cause, or be involved in car crashes as the authors advocated, since attentional dysfunction in subjects with LA have been repeatedly reported in many previous studies.