Taxonomy and Definitions for Terms Related to Cooperative Driving Automation for On-Road Motor Vehicles
This document describes machine-to-machine (M2M) communication to enable cooperation between two or more participating entities or communication devices possessed or controlled by those entities. The cooperation supports or enables performance of the dynamic driving task (DDT) for a subject vehicle with driving automation feature(s) engaged. Other participants may include other vehicles with driving automation feature(s) engaged, shared road users (e.g., drivers of manually operated vehicles or pedestrians or cyclists carrying personal devices), or road operators (e.g., those who maintain or operate traffic signals or workzones).
Cooperative driving automation (CDA) aims to improve the safety and flow of traffic and/or facilitate road operations by supporting the movement of multiple vehicles in proximity to one another. This is accomplished, for example, by sharing information that can be used to influence (directly or indirectly) DDT performance by one or more nearby road users. Vehicles and infrastructure elements engaged in cooperative automation may share information, such as state (e.g., vehicle position, signal phase), intent (e.g., planned vehicle trajectory, signal timing), or seek agreement on a plan (e.g., coordinated merge). Cooperation among multiple participants and perspectives in traffic can improve safety, mobility, situational awareness, and operations. However, nothing in this document is intended to suggest that driving automation requires such cooperation in order to be performed safely.
Cooperative strategies may be enabled by the sharing of information in a way that meets the needs of a given application. The needs may be expressed in terms of performance characteristics, such as latency, transmission mode (e.g., one-way, two-way), range, privacy and security, and information content and quality. There are several potential technologies for communicating information between the subject vehicle and other participants.
This document focuses on application-oriented functionality and does not imply the need for or require any specific functionality associated with communications protocols or the open systems interconnection model layers in a protocol stack. This document addresses the operational and tactical timescales of dynamic driving on ADS-operated vehicles, and excludes strategic functions such as trip scheduling and selection of destinations and waypoints. This information report is intended to facilitate communication and awareness for the design and anticipated development and validation of cooperative driving automation.
Cooperative driving automation technologies enable mobility applications that are not achievable by individual automated driving system (ADS)-operated vehicles operating independently of each other. These technologies do so by sharing information that can be used to increase safety, efficiency, and reliability of the transportation system, and that may serve to accelerate the deployment of driving automation in on-road motor vehicles. Driving automation and connectivity present opportunities to deploy multiple cooperative automation strategies, but successful deployment of multiple cooperative automation strategies depends on coordination among diverse stakeholders. These include road operators, intelligent transportation system (ITS) technology providers, ADS and ADS-equipped vehicle manufacturers and suppliers, as well as ADS-dedicated vehicle (ADS-DV) fleet operators. These public and private sector stakeholders are preparing for and deploying different use cases at different temporal and spatial scales. These use cases may implement vehicle strategies, such as speed harmonization and/or transportation systems management and operations (TSMO) strategies, e.g., basic travel, traffic incident management, weather management, and workzone management data sharing. The United States Department of Transportation (U.S. DOT) highlighed the importance of cooperative situational awareness standards in its guideline document “Automated Vehicles 3.0: Preparing for the Future of Transportation.”
To develop these strategies, stakeholders are engaging each other and would benefit from a common language and organization of complex technology concepts. Standardizing terms and definitions for cooperative automation and its components serves several purposes, including:
Clarifying the types of information to be exchanged during cooperative automation operations.
Clarifying cooperation capabilities (status sharing, intent sharing, agreement seeking, prescriptive) that may be required to enable cooperative automation.
Answering questions of scope when it comes to developing laws, policies, regulations, and standards.
Providing a useful framework for cooperative automation standards, specifications, technical requirements, and open-source platform development.
Providing clarity and stability in communications on the topic of cooperative automation, as well as a useful short-hand that saves considerable time and effort.
Providing a foundation and reference for future standards.
Reflecting current industry practice and preserving prior art to the extent practicable.