A vehicle (100, 150) configured to operate in an autonomous driving mode, the vehicle comprising: a driving system including a steering subsystem, an acceleration subsystem and a deceleration subsystem to control driving of the vehicle in the autonomous driving mode; a perception system (224, 258, 324) including one or more sensors configured to detect objects in an environment external to the vehicle; and a control system including one or more processors (204, 403), the control system operatively coupled to the driving system and the perception system, the control system being configured to: detect a breakdown condition of the vehicle, wherein the breakdown condition is expected to prevent continued operation of the vehicle on a roadway; in response to detection of the breakdown condition, cause the driving system to stop the vehicle along a portion of the roadway; receive sensor information from the perception system, the sensor information identifying one or more detected objects in the environment external to the vehicle; identify at least one of an object type or a predicted behavior for a given one of the one or more detected objects; characterised in that the control system is further configured to: based on at least one of the identified object type or the predicted behavior, select a communication option from among a set of communication options to alert the given object about the breakdown condition; and present information about the breakdown condition to the given object according to the selected communication option. a driving system including a steering subsystem, an acceleration subsystem and a deceleration subsystem to control driving of the vehicle in the autonomous driving mode; a perception system (224, 258, 324) including one or more sensors configured to detect objects in an environment external to the vehicle; and a control system including one or more processors (204, 403), the control system operatively coupled to the driving system and the perception system, the control system being configured to: detect a breakdown condition of the vehicle, wherein the breakdown condition is expected to prevent continued operation of the vehicle on a roadway; in response to detection of the breakdown condition, cause the driving system to stop the vehicle along a portion of the roadway; receive sensor information from the perception system, the sensor information identifying one or more detected objects in the environment external to the vehicle; identify at least one of an object type or a predicted behavior for a given one of the one or more detected objects; characterised in that the control system is further configured to: based on at least one of the identified object type or the predicted behavior, select a communication option from among a set of communication options to alert the given object about the breakdown condition; and present information about the breakdown condition to the given object according to the selected communication option. detect a breakdown condition of the vehicle, wherein the breakdown condition is expected to prevent continued operation of the vehicle on a roadway; in response to detection of the breakdown condition, cause the driving system to stop the vehicle along a portion of the roadway; receive sensor information from the perception system, the sensor information identifying one or more detected objects in the environment external to the vehicle; identify at least one of an object type or a predicted behavior for a given one of the one or more detected objects; characterised in that the control system is further configured to: based on at least one of the identified object type or the predicted behavior, select a communication option from among a set of communication options to alert the given object about the breakdown condition; and present information about the breakdown condition to the given object according to the selected communication option. based on at least one of the identified object type or the predicted behavior, select a communication option from among a set of communication options to alert the given object about the breakdown condition; and present information about the breakdown condition to the given object according to the selected communication option.