Category Archives: autonomous vehicles

It’s Time to Require Collision-Avoidance and Connected-Vehicle Technologies on all Vehicles

By Member Michael Graham

Motor vehicle crashes are a leading cause of death and injuries in the United States. Early estimates for 2020 show that more than 38,000 people lost their lives in traffic crashes on our nation’s roads. These preventable tragedies are often due to driver mistakes and poor decisions—speeding or driving while impaired, distracted, or fatigued. Collision-avoidance technologies have the potential to mitigate the impact of these mistakes by alerting a driver to impending danger or actively reducing the vehicle’s speed if the driver does not act.

“Require Collision-Avoidance and Connected-Vehicle Technologies on all Vehicles” is on the NTSB’s 2021–2022 Most Wanted List of Safety Improvements to increase public awareness about collision-avoidance systems as a lifesaving technology. The National Highway Traffic Safety Administration (NHTSA) should develop comprehensive performance standards and mandates for collision-avoidance systems and connected-vehicle technology, and we urge NHTSA to incorporate collision-avoidance system ratings into its New Car Assessment Program (NCAP).

Collision-Avoidance Systems

The primary goal of any collision-avoidance technology is to prevent and mitigate the severity of crashes by detecting a conflict, alerting the driver and, when necessary, automatically braking. A standard collision-avoidance system is comprised of two separate technologies that work together to prevent and mitigate crashes: forward collision warning and automatic emergency braking. Forward collision warning assists a driver by presenting an auditory, visual, or haptic warning to the driver before a collision. Typically, once a warning occurs and a driver does not respond, automatic emergency braking autonomously applies the brakes to prevent or mitigate a crash.

According to the Insurance Institute for Highway Safety (IIHS), an estimated 56 precent of rear‑end crashes that result in injuries could be prevented if passenger vehicles were equipped with a combination of forward collision warning and automatic emergency braking. These technologies can also improve the safety of commercial trucks. The IIHS found that equipping large trucks with both of these systems could eliminate more than 40 percent of crashes in which a large truck rear-ends another vehicle.

Despite the proven safety benefit of collision-avoidance systems, these lifesaving technologies are not required as standard options on passenger vehicles or commercial trucks. NHTSA’s regulatory inaction has delayed the broad deployment of these systems for too long. NHTSA must require forward collision warning and automatic emergency braking on all passenger vehicles and commercial trucks.

Performance Standards

Although more collision-avoidance technologies have been deployed into new vehicles recently, forward collision warning and automatic emergency braking performance and reliability vary significantly among vehicle manufacturers and models. Performance standards specify the minimum level of performance for these technologies, and NHTSA has been slow to adopt comprehensive performance standards and criteria to assess these systems. Testing protocols to assess the performance of forward collision-avoidance systems should be expanded to include common obstacles, such as traffic safety hardware, cross-traffic vehicle profiles, and other applicable vehicle shapes or objects found in the highway operating environment.  Further, testing protocols should also assess their performance at various speeds that represent the wide range of speed conditions seen in crashes, including high speeds. NHTSA should set robust minimum performance standards for both systems to provide consumers with confidence and certainty of the safety benefits of these technologies.

New Car Assessment Program

The NCAP is a government resource, developed by NHTSA, that evaluates and rates the crashworthiness of all passenger vehicles. Consumers rely on NHTSA’s vehicle safety ratings to make informed purchasing decisions for their safety and that of their loved ones. The NCAP has been an effective tool for informing the public about a vehicle’s crashworthiness; however, the current NCAP does not rate collision-avoidance technologies such as forward collision warning and automatic emergency braking. This allows a vehicle without collision-avoidance technology to achieve the same safety rating as a vehicle equipped with a highly effective collision‑avoidance system.

The NTSB recommends that NHTSA expand the NCAP to rate collision-avoidance technology performance. Such a rating can inform the public about a vehicle’s capacity to prevent and mitigate crashes, as well as differentiate collision-avoidance systems based on their performance. Incorporating collision-avoidance system ratings into the NCAP also provides an incentive for vehicle manufacturers to equip new vehicles with forward collision-avoidance systems, which can speed up deployment of such systems into all vehicles.

Connected-Vehicle Technologies

One of the most promising lifesaving collision-avoidance technologies being researched and developed for nearly three decades is connected-vehicle technology. This technology does not rely on radar or cameras but on direct communication between vehicles, called vehicle-to-vehicle (V2V) communications. This technology also allows vehicles to communicate with infrastructure and vulnerable road users such as pedestrians—collectively known as vehicle-to-everything communications (V2X).         

The NTSB’s investigations have found that V2X communications-based technology could address many crash scenarios, including many intersection crashes. Additionally, connected-vehicle technology increases the safety and visibility of vulnerable road users by alerting drivers to the presence of pedestrians, bicyclists, and motorcyclists that may be outside a driver’s or vehicle‑based sensor’s field of observation.  

However, connected-vehicle technology depends on an available communications spectrum. Currently, the entire program is at risk due to a recent decision by the Federal Communications Commission (FCC) to allow shared use of a wireless communications band previously dedicated solely for transportation safety. We are concerned that sharing this spectrum could compromise successful connected-vehicle technology deployment. The NTSB urges the FCC and others to overcome this communications challenge so connected-vehicle technology can be deployed widely and securely.

Bottom Line

Every day we lose more than 100 lives in preventable traffic crashes on our nation’s roads. Humans make mistakes that lead to crashes, but technology can mitigate those mistakes, avoiding death and serious injuries. Collision-avoidance technologies assist drivers by alerting a driver to an impending crash and automatically stopping the vehicle if the driver does not act. This proven, lifesaving technology is available today.

Tragically, regulatory inaction has slowed both deployment and broad availability of these technologies. The NTSB calls on the NHTSA to:

  • require forward collision warning and automatic emergency braking on all passenger vehicles and commercial trucks,
  • adopt comprehensive performance standards and criteria to assess these systems, and
  • expand the NCAP to rate the performance of collision-avoidance technologies.

Any further delay will cost more lives.

Incentivizing Implementation of Collision Avoidance Technology through NCAP

By Member Michael Graham

I recently participated in my first NTSB Board meeting as a member. We deliberated the findings of a crash involving a Tesla that drove into a gore area and struck a crash attenuator on a highway in Mountain View, California, killing the driver. Although this investigation was focused on level 2 automation safety issues, we also discussed the building blocks of autonomous vehicles—collision avoidance systems (CAS). In this crash, the vehicle was equipped with forward collision warning (FCW) and automatic emergency braking (AEB), elements of a CAS, but they were not designed for this kind of collision. Additionally, we discussed how testing protocols for CAS should be more demanding, and that one way to do that is through the National Highway Safety Administration’s (NHTSA) New Car Assessment Program (NCAP), its 5-star safety rating system for new automobiles. During the Board meeting, we highlighted vehicle rating systems in other countries, especially the European NCAP (Euro NCAP), and how they could—and should—be a model for the United States.

March 23, 2018, crash of a Tesla in Mountain View, California
Northbound view of the Mountain View, California, crash scene before the Tesla was engulfed in flames. (Source: witness S. Engleman)

We believe a robust NCAP is vitally important for safety. A rating system helps manufacturers assess a vehicle’s crashworthiness, which is critical, but the NCAP can also be a great tool for consumers to assess which vehicles have advanced safety technologies and provide a guide for how they work. Additionally, such a rating system gives manufacturers an incentive to improve performance. A rating system that regularly increases the criteria for achieving a top score and promotes competition, compels automakers to continually improve the technology.

The US NCAP currently only provides crashworthiness (occupant protection) ratings; it doesn’t rate advanced safety technologies, such as FCW or AEB. These technologies are already on our roadways today and American consumers have no resources available to them to evaluate the effectiveness of collision avoidance technologies. Some consumers may even be totally unaware what CAS their automobiles come with.

In May 2015,  the NTSB released a report touting the benefits of CAS and recommended that NHTSA expand the NCAP 5-star rating system to include a scale that rates CAS technology such as FCW performance. It also recommended it include the ratings on the legally required Monroney label, a window sticker that provides official data about the vehicle to consumers. We were pleased to see that, shortly after the report was released, NHTSA proposed a rule for testing procedures that would be similar to the more comprehensive testing done by European regulators. More importantly, NHTSA proposed expanding the NCAP 5-star rating to include a CAS rating, as well as pedestrian protection rating. Unfortunately, NHTSA has yet to publish a final rule to make this proposal a reality. It has issued several requests for comments regarding various aspects of testing protocols, but hasn’t moved forward to implement expansion.

The Euro NCAP, which was developed in 2009—nearly 15 years after the US NCAP—offers crashworthiness ratings as well as ratings on pedestrian protection (including cyclists) and driver-assistance and crash-avoidance technologies. Its safety assist rating for CAS is determined from tests of AEB, lane keeping, seat belt warnings, speed warning systems, and others.  Euro NCAP ratings are displayed with the consumer in mind, with easy to read and compare pictures, diagrams and tables. There is currently no federal resource for rating CAS for US consumers

The Euro NCAP, as well as organizations in Australia and Japan, recognizes what we have long known: that car-to-car rear impacts are among the most frequent crash types, making it critical to rate technologies that address these safety issues. NHTSA has established test protocols and performance specifications for FCW and AEB as part of the US NCAP. For example, if a vehicle model is equipped with FCW or AEB, and has passed NHTSA’s minimum testing protocols, NHTSA’s website will state that such a vehicle may be equipped with those features; however, that only indicates that those systems have met NHTSA’s minimum performance criteria, and the vehicle only receives a pass or fail grade. CAS that meet the performance specifications are listed only as “recommended safety technologies” in the US NCAP. We know that various FCWs differ greatly in their performance—this pass/fail rating is not enough.

Additionally, although the US NCAP and the Euro NCAP use similar scenarios in their test protocols, the Euro NCAP uses a variety of targets, such as vehicles, bicyclists, and pedestrians; tests at a greater range of  speeds; and, most importantly, rates system performance. Our Mountain View report recommends that the US NCAP be expanded even further to test forward collision avoidance systems performance using common obstacles, such as traffic safety hardware, cross-traffic vehicle profiles, and other applicable vehicle shapes or objects found in the highway operating environment.

Without a US NCAP to rate collision avoidance technologies, US consumers have had to turn to insurance research organizations for this kind of information. The Insurance Institute for Highway Safety (IIHS), for example, offers consumers vehicle reviews and ratings and issues its top safety picks. IIHS tests evaluate two aspects of safety: crashworthiness (how well a vehicle protects its occupants in a crash) and crash avoidance and mitigation (technology that can prevent a crash or lessen its severity). This is a great first step for consumers in the United States, but we need our regulators to step up and do the same.

The US NCAP has fallen behind its counterparts with respect to the safety information it provides to American consumers about CAS. We know that CAS can be very effective and can save lives, making it even more important to educate consumers about these critical technologies—their benefits as well as their limitations. That’s why this issue has been on the NTSB  Most Wanted List for several years now.


We urge NHTSA to again become a global leader by incorporating CAS and other safety performance measures in the US NCAP, and by adopting testing protocols for CAS in commercial vehicles and requiring them on all new heavy vehicles. European and other international organizations have figured out the importance of offering these expansive rating systems to help save lives and improve transportation safety. It’s time for the United States to catch up.