UL 4600 Edition 3 Updates Incorporate Autonomous Trucking

Introducing the third edition of UL 4600

Industry stakeholders continuously revise standards based on new technologies and trends. UL 4600, the Standard for Safety for the Evaluation of Autonomous Products, Edition 3 was released on March 17, 2023, to address changing industry trends. UL Standards and Engagement issued a press release on the third edition as well.

The third edition updates address an important use case: autonomous trucking. Autonomous trucking is becoming more prevalent, so it is important that the industry must provide guidance on how to deploy these vehicles safely. The following topics are covered in the third edition:

1. Revise safety case framework to support autonomous trucking
2. Revise and add examples specific to autonomous trucking
3. Add more precise definition for one preferred form of safety performance indicator (SPI)
4. Add requirements concerning post-incident behaviors in sections 10.6.6 and 10.6.7

In addressing these topics, the UL 4600 Standard updated use cases associated with autonomous trucking and definitions that are needed for this important industry.

UL 4600 Overview

UL 4600, is a goal-based and technology-agnostic Standard covering autonomous vehicles and other autonomous products operating without human supervision. This means UL 4600 requires a demonstration of how an autonomous system is developed with safety built in.

Standards like UL 4600 do not aim to be prescriptive in the technology needed to achieve safety functionality, like object detection. Rather, the safety case must credibly argue that relevant objects will be successfully detected and classified with whatever sensors are installed within the limits of the intended operational design domain. For example, using light detection and ranging (LIDAR), a specific technology, is not required in the Standard. Vehicles like autonomous trucks, tractors, construction equipment, and mining or on-road vehicles, rely on different types of sensing technology, and the Standard requires that they effectively detect nearby objects.

Additionally, UL 4600 does not dictate a fixed limit on the number of road-testing miles that must be accumulated before deployment. This is a challenge for all vehicle types, as gathering road miles can be difficult, especially when these miles are accumulated on public roads. Rather, the safety case must argue that an acceptably robust combination of analysis, simulation, closed course testing and safe public road testing have been performed to demonstrate an appropriate level of system safety for the initial vehicle and each software update.

Safety cases for autonomous vehicles require multiple frameworks to achieve safety and security

Safety for highly automated vehicles requires a complete safety case:

• Based on functional safety (ISO 26262)
• Based on SOTIF (ISO 21448)
• Based on cybersecurity (ISO 21434)
• Based on additional guidance for autonomy (UL 4600)

Autonomy safety relies on not one framework but several. For complex products, safety itself is complex. Integrators must confirm the safety arguments of suppliers. A trusted, independent third party is a crucial element for safety.

A holistic approach to vehicle safety and security

UL Solutions provides training and assessments for UL 4600 and other related standards like ISO 21448 (SOTIF), ISO 26262 (functional safety) and ISO 21434 (cybersecurity). We view the safety of highly automated and autonomous vehicles as an approach that needs not just one standard or area but a collection of best practices. UL 4600 can be a useful tool to bring these concepts together and provide excellent references to best practices, use cases and pitfalls you will encounter when developing systems for on-road and off-road vehicles. We are a trusted provider of support services to help manufacturers and suppliers understand the industry challenges and provide a pathway to safety and security.

A digital version of the Standard is available for the public online for free, or you can purchase the Standard directly through Standards and Publications.