For links to Related Automated Vehicle Topics
Forward collision avoidance systems
Systems like forward collision warning (FCW) and automatic emergency braking (AEB) are driver assistance systems that can detect forward hazards, alert the driver, and if necessary, automatically brake to prevent a crash or mitigate its severity.
The NTSB issued its first safety recommendation pertaining to FCW in commercial vehicles in 1995. Since then, we have issued more than 20 safety recommendations focusing on developing performance standards and implementing these systems in both passenger and commercial vehicles.
In 2015, we published a
special investigative report in which we recommended that passenger and commercial vehicle manufacturers install FCW and AEB as standard equipment in all new vehicles. Five months later, passenger vehicle manufacturers came to a voluntary agreement with the National Highway Traffic Safety Administration (NHTSA) and the Insurance Institute for Highway Safety (IIHS) to equip new vehicles with these systems as standard equipment by 2022.
In our 2015 report, we also recommended that NHTSA expand the US new car assessment program (NCAP) to include performance ratings of the collision avoidance systems. As of July 2024, NHTSA still has not expanded the NCAP.
In 2024, NHTSA published a final rule mandating AEB (including FCW application) in all new light vehicles, with an effective date of September 2029. The NTSB largely
supported the ruling when proposed earlier in the year. In 2023, NHTSA also published a notice of proposed rulemaking to mandate AEB on heavy vehicles. NTSB also provided
comments on this rulemaking activity.
Intelligent speed assistance
Intelligent speed assistance (ISA) is designed to help ensure that vehicle speed does not exceed a safe or legally enforced speed. ISA systems compare a vehicle’s global positioning system (GPS) location against a database of posted speed limits and then rely on onboard cameras to read speed limit signs. Passive ISA systems warn a driver when the vehicle exceeds the speed limit through visual, sound, or haptic alerts, and the driver is responsible for slowing the vehicle. Active systems include mechanisms that can either make it more difficult to increase the speed of a vehicle above the posted speed limit, or fully prevent the vehicle from exceeding the limit.
The NTSB issued its first safety recommendation on ISA for commerical vehicles in 2012. In 2017, we published the safety study, Reducing Speeding-Related Crashes Involving Passenger Vehicles, in which we asked NHTSA to incentivize adoption of ISA in passenger vehicles by including ISA in the US NCAP; however, NHTSA has not implemented this action. Unfortunately, speeding-related crashes continue to occur, and the NTSB has investigated many significant crashes involving drivers traveling at double or even triple the speed limit.
One of our recent investigations, a multivehicle collision in
North Las Vegas, Nevada, in which the driver ran a red light while traveling at 103 mph on a 35-mph roadway, causing nine fatalities, led the NTSB to issue new safety recommendations on ISA. We recommended NHTSA require ISA technology in all new vehicles that, at a minimum, warns the driver when the vehicle exceeds the speed limit. We also issued a recommendation to passenger vehicle manufacturers to implement ISA as standard equipment in new vehicles.
Connected vehicle technology or V2X
The NTSB has supported the development and implementation of connected vehicle technology for more than 20 years. Connected vehicle technology relies on direct communication with roadway users to detect impending collisions, alert the driver, and if necessary, automatically brake. Communication between vehicles is referred to as vehicle-to-vehicle (V2V), but this technology has broader applications, as it also allows vehicles to communicate with instrumented infrastructure or to detect vulnerable road users, such as pedestrians. The variety of communication targets are collectively known as vehicle-to-everything (V2X). Due to its inherent unique capabilities, such as capacity to communicate with obscured objects (e.g., a vehicle around a corner), V2X technology can complement vehicle-resident sensors, enhancing the overall safety of future automated vehicles.
The NTSB issued its first safety recommendation pertaining to V2X technology in 1995, when we recommended that the Federal Communications Commission (FCC) allocate frequency for such technology. Since then, we have investigated many crashes in which V2X technology could have prevented or mitigated the severity of a collision. In 2013, as a result of an investigation of one such crash in
Chesterfield, New Jersey, the NTSB issued safety recommendations to NHTSA to develop performance standards and mandate connected vehicle technology in all highway vehicles.
Due to the lack of appropriate response by NHTSA and the US Department of Transportation, as well as the FCC’s reduction of the allocated spectrum for transportation safety applications, the NTSB took additional actions in 2022. Following an investigation of a crash in
Mt. Pleasant Township, Pennsylvania, the NTSB issued additional recommendations to the USDOT and the FCC to resolve the current obstacles and develop a plan for nationwide deployment of V2X technology.
In 2021, NTSB also developed a video series examining the overview of the current state of V2X, the impact of the FCC actions, and the tenuous future of this technology in the United States. Learn more at the
V2X: Preserving the Future of Connected Vehicle Technology.
