Maintaining human safety during HRI is key in the integration of the humanoids in our daily lives. With this in mind, we previously proposed Asymmetric Velocity Moderation (AVM) as a way of restricting the robot speed when interacting with humans. With AVM, the robot reduces its speed according to distance and the direction of the motion. In this paper, we propose a new way of calculating the speed restriction which solves a problem of previous proposals where human safety was sacrificed due to unexpected lesser restriction. We focus on a detailed investigation of how AVM treats situations where a humanoid could endanger a human and test it using different calculation methods of the speed restriction. Finally, we evaluate the efficiency of the humanoid HRP-4 in terms of task completion time by performing simulation experiments in simple HRI scenarios.