13 research outputs found
Evaluating and rating the safety benefits of advanced vehicle technologies: developing a transparent approach and consumer messaging to maximize benefit
In 2012, a major traffic safety organization tasked the MIT AgeLab with developing a data-driven system for rating the effectiveness of new technologies intended to improve safety. Such a system was envisioned as having the potential to educate and guide consumers towards more confident and strategic purchasing decisions, ideally encouraging adoption of technologies with demonstrated safety benefit. In addition, an evaluation of the status and extent of existing data was seen as a way of identifying research gaps in the state of knowledge about safety systems. The focus was on technologies as a class, not on a rating review of individual vehicle model implementations. As conceptualized, the system aimed to complement traditional NCAP style ratings as well as to provide consumers with transparent information on early stage and often improving safety technologies. Development of the rating system and identification of data was undertaken in consultation with a range of academic, industrial, consumer, NGO, and governmental experts as well as with representatives of many of the major automotive manufacturers and suppliers.
A key observation that emerged was that data on objectively demonstrable real-world benefits were generally sparse and often lower than expectations based on theoretical considerations, simulation studies, or pre-production evaluations. A number of experts and industry representatives expressed some surprise at both the divergence between theoretical and observed benefits and the relative scarcity of data upon which to make objective assessments, while others were quite aware of these issues and the need for the development of objective data under real-world operating conditions. A number of factors that might be relevant to understanding why such differences between expected and observed benefits exist were identified. One outcome of this effort was the founding of the Advanced Vehicle Technology (AVT) consortium to collect and examine objective data under naturalistic driving conditions of how drivers interact with, engage or don’t engage, various production safety and driver assistance systems. This ongoing effort is contributing to insights concerning actual benefits and reasons for benefit gaps.
Drawing from our initial work, as well as newer sources of data, we argue that the evaluation and rating of safety and driver assistance technologies for informing the consumer and the public at large should consider both theoretical potential and existing demonstrated benefit of specific technologies. This position is increasingly relevant as the effectiveness of many newer technologies have the potential to actually improve over the lifecycle of a vehicle through software updates. The emphasis on ratings based on observed benefit for actual drivers under real-world conditions is proposed to be complementary, rather than competing with, ratings focused largely on controlled test track evaluations of engineered capability. In addition, a case is made for providing ratings that assesses benefit relative to overall crash, injury, and fatality rates – and in relation to the specific scenario / crash event type that a given technology is intended to address. This approach should aid consumers in considering the extent to which a specific technology is or is not relevant to their particular driving needs
Designing a Study to Investigate Older Novice Drivers
DTNH2217D00031/693JJ920F000207Drivers 15 to 20 years old\u2014many of whom were novice drivers\u2014represented 8.5 percent of drivers involved in fatal crashes but only 5.1 percent of all licensed drivers in 2020. Graduated driver licensing (GDL) laws are the most effective behavioral countermeasure for young drivers. However, although an increasing proportion of young people are delaying licensure until 18 or older, few States currently apply the full GDL program to 18- to 20-year-old novice drivers, and little is known about the safety and driving habits of this group. In this project the research team developed a hypothetical naturalistic driving study to investigate research questions about the safety and driving exposure of younger (15.5 to 16.5 years old) and older (18 to 20 years old) novice drivers in the first year of unsupervised (independent) driving
Non-Driving-Related Task Engagement: The Role of Speed
Non-driving-related tasks (NDRTs) have the potential to affect safety in a number of ways, but the conditions under which drivers choose to engage in NDRTs has not been extensively studied. This analysis considers naturalistic driving data in which drivers were recorded driving and engaging in NDRTs at will for several weeks. Using human-annotated video captured from vehicle cabins, we examined the probabilities with which drivers engaged in NDRTs, and we examined the relationship between vehicle speed and NDRT probability, with the goal of modeling NDRT probability as a function of speed and type of NDRT observed. We found that tasks that contain significant visual and manual components, such as phone manipulation, show strong sensitivity to vehicle speed, while other tasks, such as phone conversation, show no effects of vehicle speed. These results suggest that there are systematic relationships between NDRT patterns and vehicle speed, and that the nature of these relationships is sensitive to the demands of the NDRT. The relationship between speed and NDRT probability has implications for understanding the effects of NDRTs on safety, but also for understanding how drivers may differ in terms of the strategies they employ to modulate their NDRT behaviors based upon driving demands
Evaluating the Associations between Forward Collision Warning Severity and Driving Context
Forward collision warning (FCW) systems typically employ forward sensing technologies to identify possible forward collisions and provide an alert to the driver in the event they have not recognized a threat. These systems have demonstrated safety benefits. However, because the base rate of collisions is low, sensitive FCW systems can provide a high rate of alarms in situations with no or low probability of collision, which may negatively impact driver responsiveness and satisfaction. We examined over 2000 naturally occurring FCWs in two modern vehicles as a part of a naturalistic driving study investigation into advanced vehicle technologies. Analysts used cabin and forward camera footage, as well as environmental characteristics, to judge the likelihood of a crash during each alert, which were used to model the likelihood of an alert representing a possible collision. Only nine FCWs were considered “crash possible and imminent”. Road-type, speed, traffic density, and deceleration profiles distinguished between alert severity. Modeling outcomes provide clues for reducing nuisance and false alerts, and the method of using subjective video annotation combined with vehicle kinematics shows promise for investigating FCW alerts in the real world
Takeover Context Matters: Characterising Context of Takeover in Naturalistic Driving using Super Cruise and Autopilot
Vehicle Accessibility: Association with Novice Teen Driving Conditions
Novice teen drivers have disproportionally elevated crash rate compared to older drivers’. The high crash rate among novices is generally attributed to multiple risk factors, including driving inexperience, young age, risky driving behavior, vehicle accessibility, time of day, and driving with teenage passengers. The current naturalistic driving study with novice-teenagers evaluated the associations between vehicle accessibility (primary or shared) and driving conditions. Of 83 study participants 55 had primary vehicle access. Teens who shared a vehicle drove 22% more miles with an adult passenger in the vehicle compared to teens with primary vehicle access. Primary vehicle access was significantly associated with increased driving exposure (i.e. number of trips and miles driven) and driving with teen passengers. Driving with an adult present is protective, while greater exposure and driving with teenage passengers are known risk factors. Our findings indicate that primary vehicle access increases exposure overall and to driving with teen passengers, thereby increasing crash risk
Teen Driving Risk and Prevention: Naturalistic Driving Research Contributions and Challenges
Naturalistic driving (ND) methods may be particularly useful for research on young driver crash risk. Novices are not safe drivers initially, but tend to improve rapidly, although the pace of learning is highly variable. However, knowledge is lacking about how best to reduce the learning curve and the variability in the development of safe driving judgment. A great deal has been learned from recent naturalistic driving (ND) studies that have included young drivers, providing objective information on the nature of crash risk and the factors that contribute to safety critical events. This research indicates that most learners obtain at least the amount of practice driving recommended and develop important driving skills. Unfortunately, most learners are not exposed during training to more complex driving situations and the instruction provided by supervising parents is mostly reactive and may not fully prepare teens for independent driving. While supervised practice driving is quite safe, crash rates are high during the first six months or so of independent driving then decline rapidly, but remain high for years relative to experienced drivers. Contributing factors to crash risk include exposure, inexperience, elevated gravitational-force event rates, greater willingness to engage in secondary tasks while driving, and social influence from peer passengers. The findings indicate the need and possible objectives for improving practice driving instruction and developing innovative prevention approaches for the first year of independent driving
Vehicle ownership and other predictors of teenagers risky driving behavior: Evidence from a naturalistic driving study
Objective
Risky driving behavior may contribute to the high crash risk among teenage drivers. The current naturalistic driving study assessed predictors for teenagers’ kinematic risky driving (KRD) behavior and the interdependencies between them.
Method
The private vehicles of 81 novice teenage drivers were equipped with data acquisition system that recorded driving kinematics, miles driven, and video recordings of the driver, passengers and the driving environment. Psychosocial measures were collected using questionnaires administered at licensure. Poisson regression analyses and model selection were used to assess factors associated with teens’ risky driving behavior and the interactions between them.
Results
Driving own vs shared vehicle, driving during the day vs at night, and driving alone vs with passengers were significantly associated with higher KRD rates (Incidence rate ratios (IRRs) of 1.60, 1.41, and 1.28, respectively). Teenagers reporting higher vs lower levels of parental trust had significantly lower KRD rates (IRR = 0.58). KRD rates were 88% higher among teenagers driving with a passenger in their own vehicle compared to teenagers driving with a passenger in a shared vehicle. Similarly, KRD rates during the day were 74% higher among teenagers driving their own vehicle compared to those driving a shared vehicle.
Conclusions
Novice teenagers’ risky driving behavior varied according to driver attributes and contextual aspects of the driving environment. As such, examining teenagers’ risky driving behavior should take into account multiple contributing factors and their interactions. The variability in risky driving according to the driving context can inform the development of targeted interventions to reduce the crash risk of novice teenage drivers
Factors Influencing Learner Permit Duration
An increasing number of countries are requiring an extended learner permit prior to independent driving. The question of when drivers begin the learner permit period, and how long they hold the permit before advancing to independent licensure has received little research attention. Licensure timing is likely to be related to “push” and “pull” factors which may encourage or inhibit the process. To examine this question, we recruited a sample of 90 novice drivers (49 females and 41 males, average age of 15.6 years) soon after they obtained a learner permit and instrumented their vehicles to collect a range of driving data. Participants completed a series of surveys at recruitment related to factors that may influence licensure timing. Two distinct findings emerged from the time-to-event analysis that tested these push and pull factors in relation to licensure timing. The first can be conceptualized as teens’ motivation to drive (push), reflected in a younger age when obtaining a learner permit and extensive pre-permit driving experience. The second finding was teens’ perceptions of their parents’ knowledge of their activities (pull); a proxy for a parents’ attentiveness to their teens’ lives. Teens who reported higher levels of their parents’ knowledge of their activities took longer to advance to independent driving. These findings suggest time-to-licensure may be related to teens’ internal motivation to drive, and the ability of parents to facilitate or impede early licensure