Among the many reasons automated-driving-system (ADS)-equipped vehicles haven’t progressed more rapidly is a lack of external indication when the vehicle’s ADS is engaged, as well as the absence of a visible signal that reveals the vehicle’s intended movement.
Studies have suggested that road users would prefer ADS-equipped vehicles to have additional lamps as a means of identifying ADS-equipped vehicles and communicating the ADS-equipped vehicle’s movement or intended movement. And while there’s no standard today, the SAE J3134 Recommended Practice provides guidance in the development of a standardized lighting solution to meet these needs.
In a significant step toward that goal, Mercedes-Benz received the world's first approval for use of turquoise-colored automated-driving marker lights in California and Nevada.
Permit Details on Using Turquoise Marker Lights
In California, the permit is valid to test turquoise-colored marker lights for automated driving on freeways. The permit enables production vehicles to be equipped with special marker lights beginning with Mercedes Model Year 2026 EQS and S-Class DRIVE PILOT vehicles, the company’s SAE Level 3 self-driving system for conditionally automated driving.
DRIVE PILOT received certification two-plus years ago (2021) in Germany and in 2023 in the U.S. for Nevada and California, where each state requires separate certification. While DRIVE PILOT has already been available for order since 2022 in Germany, the first U.S. production vehicles recently made their debut on the freeways of California and Nevada.
With DRIVE PILOT, the car can drive itself at speeds of up to nearly 40 mph, although the human behind the wheel must be ready to intervene if required.
The exemption permit for California is for testing vehicles and it’s initially limited to two years. The Nevada permit applies to Mercedes-Benz Model Year 2026 production vehicles and will remain valid until a statutory modification is achieved with the state legislature.
Both permits will allow Mercedes-Benz to gain important insights into the interaction of automated vehicles and other road users. The inclusion of marker lights aims at enhancing public acceptance of automated driving and contributing to road safety, as the lights clearly visualize the automated-driving system's status on the exterior.
This also allows traffic law enforcement and police officers to identify the system's status and determine whether drivers are permitted to engage in secondary activities during the automated journey.
The turquoise-colored marker lights for automated driving in California and Nevada are integrated into the front and rear lights as well as the two outside mirrors in Mercedes-Benz testing vehicles.
"With the development of automated-driving marker lights, Mercedes-Benz is once again setting new industry standards,” said Markus Schäfer, Member of the Board of Management of Mercedes-Benz Group AG, and Chief Technology Officer, Development & Purchasing. “We are the first automaker in the world to receive such approvals in the U.S., specifically in California and Nevada. The more automated-driving vehicles populate the road, the more important communication and interaction between the vehicle and the environment become.”
Why Turquoise?
Two essential criteria contributed to the turquoise color choice—its visibility enables reliable and fast detection for other road users, and it offers differentiation from existing vehicle lighting and traffic signals such as traffic lights or emergency lighting. Thus, the possibility of confusion with already existing lighting colors may be reduced significantly.
In addition, according to the findings of numerous test studies, turquoise is the optimal color for automated driving. Both physiological and psychological factors attest to higher values in almost all areas with turquoise rather than with other colors. Turquoise is also described in the industry-recommended practice SAE J3134 "ADS Marker Lamps" to be used to display activation of an automated-driving system.
The development and approval of the new lighting concept involved collaborative efforts of an interdisciplinary team, consisting of engineers, compliance managers, data-protection experts, and ethics experts.
Customer deliveries of DRIVE PILOT-equipped Model Year 2024 EQS Sedan and S-Class models will be available in early 2024 through participating authorized Mercedes-Benz dealers in California and Nevada.
Mercedes-Benz said it’s committed to standardizing the color turquoise with the intention to visualize the automated-driving state, fostering global understanding and acceptance for this technology. So far, no general framework in the U.S., China, or the UN-ECE (United Nations Economic Commission for Europe) exists for using turquoise lights in production vehicles. California and Nevada have taken the first important step with the now-granted exemptions.
In the view of Mercedes-Benz, a future globally harmonized regulation for turquoise marker lights in automated driving will form the basis for heightened safety among all road users and propel further technical innovations.