6.8.1.1.1: Determine Personal Portable Device Guidance Method

This process shall act as the interface for personal guidance requests received from travelers with personal portable devices. The process shall select the best method for personal guidance based on data in the traveler's request. Two methods shall be available to the process, comprising dynamic infrastructure based guidance is provided to the personal portable device), and autonomous (the personal portable device uses only locally available data- there is no information provided by the infrastructure) If the communications link to the central source fails, the process shall use the last set of guidance data that was received, and if this is not sufficient for the traveler to reach the requested destination, automatically revert to the use of autonomous guidance using local data only.

This process is associated with the Personal Information Device physical object.

This process is associated with the following functional objects:

• Personal Interactive Traveler Information
• Personal METR Management
• Personal Trip Planning and Route Guidance

This process is associated with the following data flows:

• autonomous_traveler_guidance_accepted
• traveler_guidance_instructions
• traveler_guidance_request
• traveler_input_request
• autonomous_traveler_guidance_data
• autonomous_traveler_guidance_data_request
• dynamic_traveler_guidance_data
• dynamic_traveler_guidance_data_request
• traveler_guidance_accepted
• traveler_guidance_data
• traveler_route_accepted