Scenario based audible warnings for autonomous vehicles

A system for providing audible indications to objects located externally to a vehicle having an autonomous driving mode, the system comprising:

• one or more processors configured to:
• control the vehicle in the autonomous driving mode along a particular path;
• receive information identifying a characteristic of an object and a location of the object external to the vehicle;
• determine that the vehicle is prevented from proceeding along the particular path because of the location of the object;
• when the vehicle is determined to be prevented from proceeding, identify a scenario from a set of predetermined scenarios using the characteristic, each scenario of the set of predetermined scenarios being associated with a predetermined period of time and a type of audible indication;
• wait the predetermined period of time associated with the identified scenario;
• after the waiting the predetermined period of time associated with the identified scenario, determine that the object continues to prevent the vehicle from proceeding along the particular path;
• identify an audible indication according to the type of audible indication associated with the identified scenario;
• and
• when the object is determined to continue to prevent the vehicle from proceeding along the particular path, play the audible indication through a speaker of the vehicle to encourage the object to take an action to allow the vehicle to proceed along the particular path.

A non-transitory computer readable storage medium on which instructions are stored, the instructions, when executed by one or more processors cause the one or more processors to perform a method of providing audible indications to objects located externally to a vehicle having an autonomous driving mode, the method comprising:

• controlling the vehicle in the autonomous driving mode along a particular path;
• receiving information identifying a characteristic of an object and a location of the object external to the vehicle;
• determining that the vehicle is prevented from proceeding along the particular path because of the location of the object;
• when the vehicle is determined to be prevented from proceeding, identifying a scenario from a set of predetermined scenarios using the characteristic, each scenario of the set of predetermined scenarios being associated with a predetermined period of time and a type of audible indication;
• waiting the predetermined period of time associated with the identified scenario;
• after the waiting the predetermined period of time associated with the identified scenario, determining that the object continues to prevent the vehicle from proceeding along the particular path;
• identifying an audible indication according to the type of audible indication associated with the identified scenario;
• and
• when the object is determined to continue to prevent the vehicle from proceeding along the particular path, playing the audible indication through a speaker of the vehicle to encourage the object to take an action to allow the vehicle to proceed along the particular path.