A statistical analysis of the correlates of compliance and defiance of seatbelt use

With the intent to frame policy recommendations for enhancing the state of road safety, this study employed a binary logit regression approach to examine the factors associated with the compliance/defiance of seatbelt use among drivers of different vehicle types in Islamabad. To this end, a questionnaire survey was conducted to collect data on the respondents’ seatbelt use, demographic characteristics, driving behavior, past penalization history, and perceived effectiveness of enforcement of seatbelt laws. The study results revealed that there is a lower likelihood of wearing seatbelt among male drivers, taxi drivers, drivers with a low level of education, drivers with no crash or injury history, drivers that violate speed limits and are never penalized on seatbelt violation, and drivers with no seatbelt reminder installed in their vehicles. Respondents who believed that there is low effectiveness of the enforcement of seatbelt laws had the highest impact on seatbelt use whereas, the presence of seatbelt reminders in the vehicle had the least impact on seatbelt use. The findings of this study suggest the need for awareness campaigns for taxi drivers with the intent to educate them about the potential benefits of using a seatbelt in the case of a crash event; improved awareness and strict vigilance of male drivers; strict enforcement of posted speed limits and seatbelt laws; legislation for the mandatory installation of a seatbelt in all the new vehicles, and organizing mass outreach campaigns to improve the overall safety environment. Most importantly and widely applicable to the developing world, this study necessitates a depiction of strong resolve on the part of government agencies regarding the strict enforcement of seatbelt laws. Given a substantial difference in the social, cultural, and legislative outfit of the developed and developing worlds, factors influencing the compliance/defiance of seatbelt use among drivers differ significantly. It is, therefore, important to explore the local contributory factors as the results are not necessarily transferable across the regions.     

Increasing seat belt use in service vehicle drivers with a gearshift delay

This study evaluated a device that prevents drivers from shifting vehicles into gear for up to 8 s unless seat belts are buckled. Participants were 101 commercial drivers who operated vans, pickups, or other light trucks from the U.S. and Canada. The driver could escape or avoid the delay by fastening his or her seat belt before shifting out of park. Unbelted participants experienced either a constant delay (8 s) or a variable delay (M = 8 s). A 16‐s delay was introduced for those U.S. drivers who did not show significant improvement. Seat belt use increased from 48% to 67% (a 40% increase) for U.S. drivers and from 54% to 74% (a 37% increase) for Canadian drivers. The fixed delay was more effective for U.S. drivers than the variable delay, but there was no difference between these two delay schedules for Canadian drivers. After the driver fastened his or her seat belt, it tended to remain fastened for the duration of the trip.     

Field operational test of a seatbelt reminder system: Effects on driver behaviour and acceptance

The long-term effects on driver behaviour and acceptance of a seatbelt reminder system were examined in an on-road study. The system was capable of detecting seatbelt use in all seating positions and produced a two-stage visual and auditory warning if occupants were unrestrained. The effects of this system were evaluated alone and in combination with two other intelligent transport systems: intelligent speed adaptation and a following distance warning system. Twenty-three fleet car drivers drove an instrumented vehicle (SafeCar) for at least 16,500 km as part of their everyday driving. The results revealed that driver and passenger interaction with the seatbelt reminder system led to large and significant decreases in the percentage of trips where occupants were unbelted, in the percentage of total driving time spent unbelted, and in the time taken to fasten a seatbelt in response to system warnings. The seatbelt reminder system was rated by drivers as being useful, effective and socially acceptable, and led to a decrease in drivers’ subjective workload. These results were found even though the baseline pre-exposure seatbelt wearing compliance rates among participants were high.     

Changes in seatbelt use after licensing: a developmental hypothesis for novice drivers

This study tested the hypothesis that seatbelt use reflects a person's driving style or attitude towards safety, and that novice drivers' attitudes become inappropriate temporarily after licensing, and go back to being appropriate when more experience has been gained. We examined seatbelt use by university students (N=387) at a university parking lot for 19 days between April and November. Personal information about the participants was obtained from parking stickers and supplementary questionnaires asking about their driving history and attitudinal variables, such as self-assessed skill and safety. A longitudinal study indicated that seatbelt use decreased among novice drivers, but remained the same for more experienced drivers. Cross-sectional studies revealed a U curve change in seatbelt use after licensing. Regression analysis showed that overconfidence about driving skills accounted for the novice drivers' tendency to avoid using seatbelts. These results supported the hypothesis, especially for male novice drivers. The reason and implications of the changing attitude of novice drivers towards safety are discussed in terms of driver development.     

The Relation Between Perceived Risk and Preventive Action: A Within-Subject Analysis of Perceived Driving Risk and Intentions to Wear Seatbelts

Intentions to wear seatbelts in 12 different driving situations were predicted from attitudes toward wearing seatbelts, subjective norms concerning seatbelt uses, and perceived driving risk. In a given driving situation, appropriate measures of attitudes and subjective norms both had significant effects on intentions to wear a seatbelt, whereas there was little relation between risk and intentions. Intentions across the 12 driving situations were significantly related to perceived driving risk, both for aggregate data and for a substantial portion of individual subjects. However, further analyses indicated that risk seemed to affect intentions indirectly through subjective norms and attitudes associated with seat-belt use. The results suggest that attempts to increase seatbelt use should target all relevant beliefs important in determining people's attitudes toward and subjective norms concerning seatbelt use, rather than just focusing upon making people aware of the risks associated with driving.     

Effect of restricted sight distances on driver behaviors during unprotected left-turn phase at signalized intersections

During the unprotected left-turn green phase at intersections on divided highways, if the median of the major road is relatively wide, the simultaneously turning vehicles in the opposing left-turn lanes often block drivers’ views for each other so as to influence the unprotected left-turn or U-turn gap acceptance behaviors. To identify the changes of those driving behaviors clearly associated with drivers’ restricted sight distances, a field data collection in this study was conducted at a signalized intersection with the potential sight distance problem. Both linear regression and logistic regression models were developed to estimate parameters of gap acceptances. The results showed that sight obstruction due to the opposite turning vehicles may contribute to significant increments of the critical gap and follow-up time. This could result in an extra traffic delay and a capacity reduction in the left-turn lane. Moreover, it was found that left-turn or U-turn drivers with the sight distance problem were more likely to accept smaller gaps so as to cause more traffic conflicts between turning traffic and opposing-through traffic. The analyses in this paper provide a better understanding of the relationship between highway visibility and traffic safety and operation.     

Tendency to commit traffic violations and presence of passengers in the car

The present study examined whether the tendency to commit traffic violations differed when drivers were with and without the presence of other persons in the car. One thousand and eight drivers were observed by the road side. The data registered by the observers included estimated age of the driver and the passengers, sex of the driver and number of passengers. Four dependent variables were registered for each driver, which are, wearing seatbelt, signaling, using hand-held cellular phone and keeping the distance from the vehicle in front. It has been found that for both males and females, old and young, a greater proportion of drivers who were alone committed traffic violations as compared to drivers who were not alone. These results are discussed in relation to social influences on drivers and allow insight into how the presence of passengers has an impact on driver behavior and traffic safety.     

The determinants of Portuguese preference for vehicle automation: A descriptive and explanatory study

During the last century, innovation of automated vehicles (AVs) technologies are successively maturing while progressively excluding the human intervention in vehicle driving. The objective of this paper was to analyze the determinants of Portuguese drivers’ decision to adopt AVs technologies, in an under explored context, where the driver of contemporary vehicles does all or part of the dynamic driving task (DDT) in comparison to vehicles equipped with Automated Driving systems (ADS) where the driver can become a passenger temporarily or permanently. In addition, willingness-to-pay for ADS estimates were also investigated. This study data was collected through a survey designed and deployed in Portugal. A mixed logit model was estimated, and the results obtained are in line with the literature of AVs in a number of determinants, but also highlights differences that can be explained by the Portuguese cultural, social and economic context. Overall, 83.7% of the Portuguese drivers favor contemporary vehicles, today, and among those who prefer vehicles with ADS, highly educated drivers’ are willing to pay, on average, 65,671 € for Conditional AVs, 31,185 € for Highly AVs, and about 28,622 € for Full AVs.     

Evaluating the effect of delay spacing on delay discounting: carry‐over effects on steepness and the form of the discounting function

Most delay discounting studies use tasks that arrange delay progressions in which the spacing between consecutive delays becomes progressively larger. To date, little research has examined delay discounting using other progressions. The present study assessed whether the form or steepness of discounting varied across different delay progressions. Human participants completed three discounting tasks with delay progressions that varied in the time between consecutive delays: a standard (increasing duration between delays), linear (equal duration between delays), and an inverse progression (decreasing duration between delays). Steepness of discounting was generally reduced, and remained so, following experience with the inverse progression. Effects of the delay progression on the best fitting equation were order‐dependent. Overall the hyperbola model provided better fits, but the exponential model performed better with data from the inverse progression. Regardless, differences in which model fit best were often small. The finding that the best fitting model was dependent, in some cases, on the delay progression suggests that a single quantitative model of discounting may not be applicable to describe discounting across all procedural contexts. Ultimately, changes in steepness of discounting following experience with the inverse progression appeared similar to anchoring effects, whose mechanism will require further study to delineate.     

Self-control in adult humans: variation in positive reinforcer amount and delay.

In five experiments, choice responding of female human adults was examined, as a function of variations in reinforcer amount and reinforcer delay. Experiment 1 used a discrete-trials procedure, and Experiments 2, 3, 4, and 5 used a concurrent variable-interval variable-interval schedule. Reinforcer amount and reinforcer delay were varied both separately and together. In contrast to results previously reported with pigeons, the subjects in the present experiments usually chose the larger reinforcers even when those reinforcers were delayed. Together, the results from all the experiments suggest that the subjects followed a maximization strategy in choosing reinforcers. Such behavior makes it easy to observe self-control and difficult to observe impulsiveness in traditional laboratory experiments that use adult human subjects.     

Increasing motorist compliance and caution at stop signs.

This study evaluated strategies to improve motorist compliance and caution at three stop‐sign‐controlled intersections with a history of motor vehicle crashes. The primary intervention was a light‐emitting diode (LED) sign that featured animated eyes scanning left and right to prompt drivers to look left and right for approaching traffic. Data were scored from videotape on the percentage of drivers coming to a complete stop and the percentage of drivers looking right before entering the intersection. Observational data were collected on the percentage of right‐angle conflicts (defined as braking suddenly or swerving from the path to avoid an intersection crash). The introduction of the LED sign according to a multiple baseline across the three intersections was associated with an increase in the percentage of vehicles coming to a complete stop at all three intersections and a small increase in the percentage of drivers looking right before entering the intersections. Conflicts between vehicles on the major and minor road were also reduced following the introduction of the animated eyes prompt.     

Measurements of gaze movements while driving

In this study, gaze movements of drivers driving through an intersection were investigated. Gaze movements of drivers in large vehicles were compared with those in small vehicles. There were both similarities and differences in the visual search behaviors of drivers of large and small vehicles. The two groups were similar in that, when approaching an intersection, drivers made repeated saccadic gaze movements; after entering the intersection, saccadic gaze movements were directed ahead in the direction of turning. Differences arose in the frequency and distribution of gaze movements. The number of gaze movements was significantly greater in drivers of large vehicles. The distribution of gaze movements in driving a large vehicle showed a peak at the point 50 to 60 degrees to the right and left of the median plane of the driver. The distribution of gaze movements of drivers of small vehicles showed no peak across the visual field.     

Changeover delay and concurrent-schedule performance in domestic hens

Six domestic hens were exposed to a series of five pairs of two-key concurrent variable-interval schedules with a range of changeover delays from no delay to 15 s. Times spent responding on each alternative and total, within_, and post-changeover-delay response ratios were analyzed in terms of the generalized matching law. The sensitivity parameters, a, for response and time data were generally low when no changeover delay was programmed but were not 0.0. They were higher for all other changeover-delay values, with some tendency to increase as the changeover delay lengthened at very short delays. Within-delay responding was insensitive to reinforcement-rate differences at all changeover delays (a values close to 0.0). As a result of this insensitivity, post-changeover-delay responding was more sensitive to reinforcement-rate changes than was total responding. Interchangeover intervals increased systematically with changeover-delay duration. Responding, particularly after the changeover delay, was well predicted by an equation based on a reinforcer-loss model.     

The role of drivers’ social interactions in their driving behavior: Empirical evidence and implications for car-following and traffic flow

Models for describing the microscopic driving behavior rarely consider the “social effects” on drivers’ driving decisions. However, social effect can be generated due to interactions with surrounding vehicles and affect drivers’ driving behavior, e.g., the interactions result in imitating the behavior of peer drivers. Therefore, social environment and peer influence can impact the drivers’ instantaneous behavior and shift the individuals’ driving state. This study aims to explore empirical evidence for existence of a social effect, i.e., when a fast-moving vehicle passes a subject vehicle, does the driver mimic the behavior of passing vehicle? High-resolution Basic Safety Message data set (N = 151,380,578) from the Safety Pilot Model Deployment program in Ann Arbor, Michigan, is used to explore the issue. The data relates to positions, speeds, and accelerations of 63 host vehicles traveling in connected vehicles with detailed information on surrounding environment at a frequency of 10 Hz. Rigorous random parameter logit models are estimated to capture the heterogeneity among the observations and to explore if the correlates of social effect can vary both positively and negatively. Results show that subject drivers do mimic the behavior of passing vehicles –in 16 percent of passing events (N = 18,099 total passings occurred in freeways), subject vehicle drivers are observed to follow the passing vehicles accelerating. We found that only 1.2 percent of drivers normally sped up (10 km/hr in 10 s) during their trips, when they were not passed by other vehicles. However, if passed by a high speed vehicle the percentage of drivers who sped up is 16.0 percent. The speed change of at least 10 km/hr within 10 s duration is considered as accelerating threshold. Furthermore, the acceleration of subject vehicle is more likely if the speed of subject driver is higher and more surrounding vehicles are present. Interestingly, if the difference with passing vehicle speed is high, the likelihood of subject driver’s acceleration is lower, consistent with expectation that if such differences are too high, the subject driver may be minimally affected. The study provides new evidence that drivers’ social interactions can change traffic flow and implications of the study results are discussed.     

Examining children's ability to delay reward: Is the delay discounting task a suitable measure?

Discounting the value of delayed rewards has primarily been measured in children with the delay of gratification task and in adolescents and adults with the delay discounting task. In the present study, we assessed the suitability of the delay discounting task as a measure of temporal discounting in children. A sample of 7- to 9-year-olds (N = 98) completed a delay discounting task, a delay of gratification task, a sensation seeking measure, and IQ measures. In addition, teacher-based assessments of attention-deficit/hyperactivity disorder traits were measured. The results indicated that the majority of children produced meaningful data on the discounting task and discounted rewards hyperbolically. Children with an elevated risk of attention-deficit/hyperactivity disorder showed a trend towards discounting future rewards on the delay discounting task more steeply than did those at low risk. However, delay discounting was unrelated to either delay of gratification or sensation seeking. We interpret these results as providing some support for the use of delay discounting as a measure of intertemporal choice in children, although the results also suggest that delay discounting and delay of gratification tasks may tap different processes in this population.     

Effects of signaled versus unsignaled delay of reinforcement on choice

Pigeons chose between 5-s and 15-s delay-of-reinforcement alternatives. The first key peck to satisfy the choice schedule began a delay timer, and food was delivered at the end of the interval. Key pecks during the delay interval were measured, but had no scheduled effect. In Experiment 1, signal conditions and choice schedules were varied across conditions. During unsignaled conditions, no stimulus change signaled the beginning of a delay interval. During differential and nondifferential signal conditions, offset of the choice stimuli and onset of a delay stimulus signaled the beginning of a delay interval. During differential signal conditions, different stimuli were correlated with the 5-s and 15-s delays, whereas the same stimulus appeared during both delay durations during nondifferential signal conditions. Pigeons showed similar, extreme levels of preference for the 5-s delay alternative during unsignaled and differentially signaled conditions. Preference levels were reliably lower with nondifferential signals. Experiment 2 assessed preference with two pairs of unsignaled delays in which the ratio of delays was held constant but the absolute duration was increased fourfold. No effect of absolute duration was found. The results highlight the importance of delayed primary reinforcement effects and challenge models of choice that focus solely on conditioned reinforcement.     

ENFORCEMENT OR INCENTIVES? PROMOTING SAFETY BELT USE AMONG MILITARY PERSONNEL IN THE NETHERLANDS

During a nationwide campaign to promote safety belt use among military personnel, a field study was conducted at 12 different military bases in the Netherlands. Amount of enforcement, type of publicity, and incentive strategies were varied among military bases. Observations of safety belt use among servicemen in their personal vehicles were conducted before the campaign, immediately following the campaign, and 3 months later. Safety belt use increased from 65% during baseline to 73% directly after the campaign and to 76% 3 months later. An overall 28.6% increase in safety belt use (from 63% to 81%) was observed at seven bases, whereas no changes were found at five bases (68% on all occasions). To a large degree the effects were due to a 37.7% increase among young drivers. These results confirmed that enforcement, as well as incentives, can be effective in promoting safety belt use. However, treatment effects were not systematic, thereby complicating the interpretation of the results. Implications of these varied outcomes are discussed.     

Comparing Delay Discounting Rates When Using the Fill-in-the-Blank and Multiple-Choice Methods

Several methods have been devised to measure delay discounting. The present study recruited university students to complete a delay-discounting task involving five different outcomes (finding a dating partner, free cigarettes, winning $100,000, being owed $100,000, and obtaining one's ideal body image) that was administered using either the fill-in-the blank (FITB) or multiple-choice (MC) method. Results showed that the different administration methods sometimes produced significantly different rates of discounting, the direction of which differed by outcome. Hyperbolic discounting and the area under the discounting curve were nearly always significantly correlated when the FITB method was used but were never significantly correlated when the MC method was used. Discounting across the five outcomes produced a two-factor solution when the FITB data were factor analyzed. The MC data were described by a one-factor solution. The present results illustrate that procedural variables have a potentially profound impact on delay-discounting data, and generalizing from studies on delay discounting should be done with caution until those variables are fully understood.     

The need for speed: Scores on a new video-based measure of speeding propensity,suitable for use in online research,correlate with drivers’ on-road speeding behaviour

A video-based measure of drivers’ speeding propensity (the UQ Video Speed Test) was developed for use in both laboratory-based and online research studies. In the test, the respondent is presented with a series of 16 video clips of traffic footage, which were shot from the driver’s perspective using a camera mounted behind the windscreen of a moving car. For each clip, the respondent’s task is to indicate to what extent they would travel faster or slower than the speed of the camera car. Responses to all clips are averaged to determine the respondent’s overall score. In the present study, we investigated associations between drivers’ video speed test scores and five measures of real everyday speeding behaviour obtained over a 5-week period using GPS trackers. There was a significant positive correlation for each of the five on-road speeding measures. In addition, age-related differences in test scores were consistent with observed real-world group differences in speeding behaviour. Test scores also correlated with an established self-report questionnaire measure of speeding (i.e., the Speed Scale from the Driving Style Questionnaire). Overall, the data supported the use of the UQ Video Speed Test as a proxy measure of drivers’ real-world speeding behaviour in laboratory-based and online studies (though it would be inadvisable to use such tests in the assessment of drivers for licensing purposes, due to the potential to “fake good”). The test can be deployed using standard online survey platforms (e.g., Qualtrics), and is available at no cost for use in driving research.