A materials handling vehicle comprises an obstacle scanning tool and steering mechanism, materials handling hardware, vehicle drive mechanism, and user interface that facilitate movement of the materials handling vehicle and materials handled along a travel path. The tool establishes a scan field, a filter field, and a performance field, and is configured to indicate the presence of obstacles in the filter field and the performance field. The tool executes logic to establish the performance field in response to an input performance level, scan for obstacles in the filter field and the performance field, execute obstacle avoidance for obstacles detected in the filter field, and execute a performance level reduction inquiry for obstacles detected in the performance field wherein outcomes of the inquiry comprise reduction of the performance level when a performance level reduction is available and execution of obstacle avoidance when a performance level reduction is not available.