In many motorized countries, concern has been growing about driving under the influence of substances other than alcohol, i.e. illicit drugs such as cannabis and amphetamine, as well as medicinal drugs such as sedatives and antihistamine.　These drugs affect central nervous system, thus may impair driving performance and pose danger to traffic safety.　The nature of the problem and the current scientific evidence is yet unknown in Japan.　This report aimed to overview the issue of drug driving by way of systematic literature search of studies published between 2000 and 2012.　A total of 62 peer-reviewed articles and relevant reports have been identified that include meta-analyses, systematic/narrative reviews, or original investigations into the risk of traffic accident or impairment caused by drug driving.　The present work attempted to summarize epidemiological research estimating accident risk of drug driving, experimental research investigating effects of drug impairment on driving performance, and finally, current interventions aiming at efficient detection of drug driving.　Further research needs, future research direction in traffic psychology, and implication to traffic safety in Japan is discussed.

The present study investigated effectiveness of individual training for lower-grade elementary school children on their crossing behavior in traffic safety training situations and on a real road. Twenty-three lower-grade elementary school children aged 6 to 7 participated in the training. In the training, each child was asked to cross a simulated road in the room while instructors observed his or her behavior. After each observation, instructors counseled children individually to modify their crossing behavior (behavior-modification) and then asked the children to cross the simulated road again. The children’s crossing behavior was recorded by video cameras. The authors analyzed the children’s crossing behavior in the training situation before and after the behavior-modification. In addition, the authors observed the children’s crossing behavior on the real road before and after the training. The results indicated that the number of checks in the training situations was increased after the individual training. However, the time for checking after training was the same as before. Moreover, the training had no influence on children's behavior on the real road. The findings are discussed in terms of effectiveness of individual training for lower-grade elementary school children.

The purpose of this study was to categorize drivers into several groups based on their characteristics when using an information presentation system to reduce velocity.　Reducing the velocity of a car is very effective at preventing traffic accidents, especially those between vehicles and pedestrians.　This information presentation system is used by the driver to stay below the speed limit and can be developed at a low cost.　In this study, the driving characteristics of seventeen drivers were investigated through an experiment with actual vehicles and a questionnaire.　In addition, the Intelligent Speed Adaptation （ISA） system was developed to present information during the experiments.　The test course for the experiment was set up on public roads in the Zone-30 area, which has a speed limit of 30 km/h.　Based on the results, factor analysis was conducted to clarify the individual differences between the seventeen drivers regarding the effect of the ISA system.　The analysis confirmed that there were many individual differences.　Therefore, cluster analysis was performed to categorize the driver characteristics into groups. Based on the results, four driver groups were determined.　The ISA system can be improved by optimizing the human-machine interface of the device to each group.　If the ISA system is to be made commercially available, it should better implement a function that can categorize a driver into a driver group automatically without cluster analysis.　Therefore, the characteristics of each driver group were clarified through the use of state variables regarding vehicle maneuvers such as the velocity or acceleration.　This study focused on the frequency distribution of the velocity and the jerk regarding acceleration and deceleration.　The results suggest that the frequency distribution of the velocity can be used to categorize the driver groups, and the jerk （i.e., fluctuation in acceleration and deceleration） showed some characteristic tendencies for each group.