Personal Mobility (PM) is required to avoid pedestrians considering the impact on both rider and pedestrians in order to move autonomously on sidewalks. The objective of this study is to propose and evaluate a new strategy of safe and secure autonomous collision avoidance based on risk evaluation. Subjective evaluations of autonomous pedestrian avoidance show that a pedestrian, walking in front of the PM, can mentally influence on a rider. This result leads the strategy to calculate risk more highly when pedestrians are in front of the PM. The safety of the locomotion based on this proposed strategy is evaluated by theoretical simulation. The validity of the proposed strategy is verified by subjective evaluations through the experiment, using a powered wheelchair simulator.