Preparing for Automated Driving Systems
Weighty questions about the technologies include how the current standard for stability control testing can be amended for ADS vehicles that have no steering wheel.
- By Jerry Laws
- Mar 01, 2018
Three U.S. Department of Transportation units published requests for comments in January 2018, input meant to help DOT define the requirements standards needed for efficient, safe Automated Driving Systems (ADS). At the same time, Transportation Secretary Elaine Chao discussed the department's progress on preparing for automated vehicles at the CES 2018 show in Las Vegas: "Autonomous vehicle technologies will have a tremendous impact on society in terms of safety, mobility, and security," she said in comments addressing Federal Automated Vehicle Policy 3.0, also known as A Vision for Safety 3.0. It will emphasize a unified, intermodal approach to ADS policy and will allow for the safe integration of automated transportation systems, including cars, trucks, light rail, infrastructure, and port operations, according to DOT.
The automated vehicle notices published in January by the Federal Highway Administration (FHWA) and the National Highway Traffic Safety Administration (NHTSA) ask for comments by mid-March 2018 from the public and from stakeholders such as state and local agencies, vehicle manufacturers, and software developers to identify barriers to implementing automated technologies and to help shape initiatives. (The third request from the Federal Transit Administration concerns transit bus automation, not addressed in this article.)
The outreach from FHWA and NHTSA gives a sense of the many challenges these emerging technologies pose for current standards and infrastructure. An example in NHTSA's request is its question about automated vehicles with controls accessed through smart phones and with unconventional interiors—how, it asks, should the agency address those?
For example, the FHWA request1 asks whether there are certain infrastructure elements (such as signage, signals, and lane markings) that are necessary for ADS and, if so, what challenges exist for ADS to interpret them. Other key questions FHWA is asking at this point include:
- What roadway characteristics are important for influencing the safety, efficiency, and performance of ADS?
- What challenges do non-uniform traffic control devices present for automated technologies, and how does this affect the costs of ADS systems?
- What types of data transmission between ADS and roadside infrastructure could enhance safe and efficient ADS operation?
- What concerns do state and local agencies have about ADS infrastructure planning and investment, "given the level of uncertainty around the timing and development of this technology."
- What are the priority issues that road owners and operators need to consider in terms of infrastructure requirements, modifications, investment, and planning, to accommodate ADS integration?
- What variable information or data would ADS benefit from obtaining, and how should those data (such as incidents, special event routing, bottleneck locations, weather conditions, etc.) be best obtained?
- What issues do road owners and operators need to consider in terms of infrastructure modifications and traffic operation as they encounter a mixed vehicle fleet—such as fully automated, partially automated, and non-automated; as well as cooperative and unconnected? And what are the most likely significant impacts of ADS on other motorized and non-motorized users of public roads?
The NHTSA request2 is significantly longer at 30 pages, as to be expected because it concerns the motor vehicles rather than the infrastructure.
The request explains that almost all of the agency's more than 60 existing Federal Motor Vehicle Safety Standards, known as FMVSS, were developed "well before vehicles with ADS became a practicable possibility." As a result, the performance requirements and test procedures laid out in many FMVSS assume there will be a human driver in a vehicle's left front seat who needs certain controls and displays in order to do the driving.
"A further and even more basic assumption is that there will be at least one occupant in each vehicle," it says. "In the case of ADS delivery vehicles without manual driving controls, this assumption may prove incorrect. If, instead, a vehicle is designed so that only an ADS can drive it and vehicle designers modify the passenger compartment to take advantage of the flexibility afforded them if a human driver is not needed, then many of those assumptions will likely be invalid for that vehicle, and some may actually be problematic from a testing perspective."
NHTSA then listed a few potential problems and asked commenters to identify others. The ones NHTSA listed include these:
- If the FMVSS can't specify where controls and displays are located, it is not clear for which occupant or seating position they must be visible, or even if they're necessary at all.
- Are current performance requirements still needed in the standards? Would occupants still need warning telltales and other displays if they have no means of driving their vehicles, for example? And what are the safety ramifications of having no telltales before or during trips?
- If future ADS vehicles have no means of human control, how can DOT and vehicle manufacturers conduct compliance tests, such as for stopping distance, that currently are conducted by human drivers on test tracks?
- FMVSS No. 126, Electronic stability control systems for light vehicles, requires the use of an automated steering machine that depends on a vehicle's steering wheel during compliance testing. How should the standard be amended to allow for stability control testing of ADS vehicles that have no steering wheel?
So there will be no misunderstanding among stakeholders or the public, NHTSA explains in the document that no current FMVSS or any other kind of legally binding standard contains provisions that are designed to address the self-driving capability of a motor vehicle, and further, there is nothing in current FMVSS to prohibit ADS. "Likewise," it says, "nothing in those standards poses testing or certification challenges for vehicles with ADSs so long as the vehicles have means of manual control and conventional seating."
The FMVSS must be "objective, practicable, and meet the need for safety," according to the Vehicle Safety Act, so the agency in some instances will require research in order to develop revised test procedures and performance criteria. The request for comments is intended to help define the needed research and establish priorities in conducting it, NHTSA says.
New NHTSA Research Under Way
NHTSA says in the document that it began evaluating the FMVSS in 2015 for potential barriers to automated technologies, contracting with DOT's Volpe Center that year to review the standards. Volpe's review concluded there are few barriers for a vehicle with ADS to comply with the FMVSS, as long as the vehicle doesn't significantly diverge from conventional design. However, Google had alerted NHTSA by a Nov. 12, 2015, letter that it planned to develop a vehicle without a steering wheel, accelerator, or brake pedal.
NHTSA says it began a new research project at the start of FY2018 on solving the challenges identified in the Volpe review and has contracted with the Virginia Tech Transportation Institute to perform the research. The project is being conducted by a core team consisting of FMVSS experts; General Motors and Nissan; testing facilities Dynamic Research, Inc. and MGA Research Corporation; and research institutions Booz Allen Hamilton and the Southwest Research Institute.
Their research will review new vehicle designs and establish an evaluation process; within the next 12 months, the project is expected to produce "robust alternative approaches" to demonstrate compliance with current FMVSS' test procedures that present challenges, says NHTSA, adding that results of the research will be made public after the project is finished.
Are there ways to solve the problems that any FMVSS poses without rulemaking, such as through interpretation, the request asks, asking any commenter who believes legislation may be necessary to explain why, to identify the existing law that should be changed, and to explain how it should be changed.
One of the questions asks whether for a vehicle driven only by an ADS, does the ADS need some or all of the same information that is currently provided for a human driver? "For example, does the ADS need to know if the tires are underinflated? Why or why not?"
NHTSA also asks commenters whether they believe research should be done to determine whether any additional controls, such as an emergency stop button, may be necessary for safety or public acceptance if all manual controls are removed from fully self-driving vehicles.
This article originally appeared in the March 2018 issue of Occupational Health & Safety.