Last month, the National Highway Traffic Safety Administration (NHTSA) indicated it was taking an adaptive policy to address and encourage the fast-paced development of autonomous vehicles.  The NHTSA develops and interprets the Federal Motor Vehicle Safety Standards, or FMVSS, which are federal safety regulations for motor vehicles and most vehicle components and design features.  The NHTSA also enforces compliance with the FMVSS through testing.  While autonomous vehicles may introduce a sea change in society by improving safety while impacting commute time, these autonomous vehicles must first satisfy the required safety regulations.  The NHTSA recently provided its interpretation of key terms of the FMVSS.[1]  Such interpretations are key to safety compliance and commercial availability of autonomous vehicles continues.

Self-Driving Software as "Driver"

Many regulations in the FMVSS include language predicated on human-operated vehicles rather than autonomous vehicles.  If an autonomous vehicle cannot fit within the terms of the FMVSS, then that vehicle cannot comply with FMVSS safety regulations.  Commercial viability of autonomous vehicles requires agencies such as the NHTSA to develop new standards and compliance testing.  For example, the FMVSS currently defines a "driver" as "the occupant of a motor vehicle seated immediately behind the steering control system."[2]  This definition, however, fails to accurately describe the "driver" of an autonomous vehicle, particularly when an autonomous vehicle may be entirely unoccupied.  This is not unexpected where a vehicle with a Level 4 Full Self-Driving Automation "perform[s] all safety-critical driving functions" and the driver "is not expected to be available for control at any time during the trip."[3]

Recognizing the above, the NHTSA interpreted the "driver" under the FMVSS for such autonomous vehicles to be the software and the driving position as the front left position.  The NHTSA noted that "[i]f no human occupant of the vehicle can actually drive the vehicle, it is more reasonable to identify the "driver" as whatever (as opposed to whoever) is doing the driving."  For an autonomous vehicle, it is the software that is actually driving the vehicle.[4]

NHTSA's Adaptive Policy for Autonomous Vehicles

These interpretations of "driver" and "driver position" help make existing standards more applicable to self-driving cars, foregoing the option of interpreting the term "driver" as meaningless where there is no human driver.  This allows the NHTSA to adapt existing rules and standards rather than develop standards anew, hastening the overall process for an autonomous vehicle to successfully meet the FMVSS.  For example, the FMVSS requires that a number of vehicle controls, such as cruise control, be available to the driver.[5]  In light of its interpretation of the "driver" above, the NHTSA stated that such controls "need not be located so that they are available to any of the human occupants of the motor vehicle."[6]  The controls simply have to be operable by the software driver. This interpretation clarifies the requirements to meet FMVSS regulations for developers considering driver access to controls for turn signals, hazard lights, headlights, wipers, washer-wipers, defrost, read defrost, engine start and stop, heating and air conditioning, fan, horn, lights, and headlight control as well.

NHTSA Shows Willingness to Embrace Self-Driving Technology

Unfortunately, not all requirements can be adapted so easily based on the NHTSA’s interpretation of the "driver." The FMVSS also requires that indicators be visible to the driver; because the driver is software, there is no defined way for the NHTSA to verify compliance with this requirement.[7] Similarly, the FMVSS require self-cancelation of a turn signal based on steering wheel rotation and a manual control to cancel a turn signal.[8] While the FMVSS do not require a steering wheel and the NHTSA indicated it would agree that software-controlled canceling of a turn signal may satisfy the self-cancelation requirement, the requirement for a manual control to cancel the turn signal "cannot be addressed through interpretation alone."[9] The NHTSA indicated it had the same problem with the regulation requiring a control to manually switch between low and high beams. The NHTSA recognized that further rulemaking will be necessary to determine whether the above requirements are appropriate for autonomous vehicles and how to amend them to ensure autonomous vehicles could comply. However, the NHTSA noted that in the interim, these issues may be resolved by a well-supported petition for an exemption that shows the autonomous vehicle satisfies a standard "providing equal or greater safety" than the FMVSS provisions at issue.[10]

Innovators are pushing the boundaries of long-established regulations for safe cars. While autonomous vehicles are quickly becoming a reality—they are a daily sight in Silicon Valley—our existing framework for defining safety compliance is still based on century-old practices. The NHTSA’s recent response demonstrates a willingness to interpret its rules and compliance testing to embrace self-driving cars and begin the process of adapting its policies to embrace this emerging technology. The NHTSA’s positions should provide a blueprint for how agencies may evaluate autonomous vehicle implementations to developers in this area, providing some guidance and encouraging the development of self-driving car solutions