Looked-but-failed-to-see-errors in traffic

Danish studies of traffic accidents at priority intersections have shown a particular type of accidents. In these accidents a car driver supposed to give way has collided with a bicycle rider on the priority road. Often the involved car drivers have maintained that they did not see the bicycle until immediately before the collision even though the bicycle must have been clearly visible.

Similar types of accidents have been the subject of studies elsewhere. In literature they are labelled “looked-but-failed-to-see”, because it seems clear that in many cases the car drivers have actually been looking in the direction where the other parties were but have not seen (i.e. perceived the presence of) the other road user. This paper describes two studies approaching this problem.

One study is based on 10 self-reported near accidents. It does show that “looked-but-failed-to-see” events do occur, especially for well experienced drivers. The other study based on Gap Acceptance shows that the car driver acceptance of gaps towards cyclists depends on whether or not another car is present. Hypotheses for driver perception and for accident countermeasures are discussed.     

Reductions in driver speed using posted feedback of speeding information: social comparison or implied surveillance?

Reducing driver speed has an essential role to play in traffic safety. This study measured the effect of a roadside sign, in a 50 km/h zone, that consecutively displayed one of three messages:

1. The average speed at the site: this message was designed to induce “social comparison” whereby drivers may reduce their speed in order to comply with the behaviour of the majority.

2. A warning that drivers’ speeds were being measured: this was intended to imply surveillance whereby drivers may reduce speed in order to avoid possible enforcement action.

3. A combination of both messages, to see if both together would have a greater effect than either alone.

The speed of drivers travelling along a busy urban road (11,500 cars daily in each direction) was measured using inductive loop detectors. The proportion of drivers travelling 60 km/h or less increased with all three messages, suggesting that both social comparison and implied surveillance are mechanisms by which driver speed may be reduced. However, the speed reductions were not as great as in previous studies of feedback signs. This may be due to differences in the existing safety culture.     

Tiredness and visual reaction time among nighttime cab drivers: A roadside survey

The present roadside survey seeks to elucidate the incidence of tiredness among nighttime cab drivers by comparing self-assessed level of tiredness with the results of a simple visual reaction test. Attempts to separate various forms of fatigue from sleepiness are not made, as it appears less important in studies of everyday traffic than in experimental investigations. One-hundred-and-twenty cab drivers of vacant cabs were stopped by the police on a major highway just outside the city of Copenhagen. Eighty drivers declared themselves rested, 38 tired, and 2 very tired. The reaction test showed considerable individual variation, but subdivision of the drivers according to level of tiredness demonstrated a statistically significant and uniform difference throughout the night (p < 0.0001). One self-assessed tired driver was reclassified to the group of very tired based on the questionnaire and reaction test. The investigation indicates that accidents due to “driver asleep” would be expected among the three (2.5%) very tired cab drivers. The questionnaire and visual reaction test turned out to be complementary in the present study and are both useful implements for future roadside surveys of tiredness in nighttime traffic.     

Data Based Violated Behavior Analysis of Taxi Driver in Metropolis in China

Violation probability of taxi drivers in metropolis is far more than that of normal drivers because they are labor-intensive, overconfident of self-driving skill, and always searching potential customers, sometimes even picking up or dropping off passengers randomly. In this paper, four types of violated behavior of taxi drivers in metropolis were first summarized, based on which corresponding scale table was initial designed with social statistical method. Furthermore, with certain samples, relative item analysis, exploratory factor analysis, validity analysis and reliability analysis were conducted to verify validity of the initial scale table, based on which some improvements were made, and we can see that the modified scale table in the paper has high fitness degree, good reliability and validity to detect violated behavior of taxi driver accurately. Finally, large area survey data of taxi driver questionnaire from Shanghai was collected with the modified scale table above, the analysis results showed that among four types of violated behavior of taxi drivers in metropolis, the probability over-speed is top to 89.57%, in which probabilities of behaviors of “driving over-speed at mid-night” and “accelerating to across the intersection during the yellow signal” are top to 64.2% and 58.2% respectively, which is meaningful for the improvement of taxi drivers’ behaviors specification and traffic safety regulation.     

Augmented reality cues to assist older drivers with gap estimation for left-turns

The objective of this study was to assess the effects of augmented reality (AR) cues designed to assist middle-aged and older drivers with a range of UFOV impairments, judging when to make left-turns across oncoming traffic. Previous studies have shown that AR cues can help middle-aged and older drivers respond to potential roadside hazards by increasing hazard detection without interfering with other driving tasks. Intersections pose a critical challenge for cognitively impaired drivers, prone to misjudge time-to-contact with oncoming traffic. We investigated whether AR cues improve or interfere with hazard perception in left-turns across oncoming traffic for drivers with age-related cognitive decline. Sixty-four middle-aged and older drivers with a range of UFOV impairment judged when it would be safe to turn left across oncoming traffic approaching the driver from the opposite direction in a rural stop-sign controlled intersection scenario implemented in a static base driving simulator. Outcome measures used to evaluate the effectiveness of AR cueing included: Time-to-Contact (TTC), Gap Time Variation (GTV), Response Rate, and Gap Response Variation (GRV). All drivers estimated TTCs were shorter in cued than in uncued conditions. In addition, drivers responded more often in cued conditions than in uncued conditions and GRV decreased for all drivers in scenarios that contained AR cues. For both TTC and response rate, drivers also appeared to adjust their behavior to be consistent with the cues, especially drivers with the poorest UFOV scores (matching their behavior to be close to middle-aged drivers). Driver ratings indicated that cueing was not considered to be distracting. Further, various conditions of reliability (e.g., 15% miss rate) did not appear to affect performance or driver ratings.     

Driver irritation and aggressive behaviour

A sample of 98 drivers responded to a Swedish version of the UK Driving Anger Scale [UK DAS; [Lajunen, T., Parker, D., Stradling, S.G., 1998. Dimensions of driver anger, aggressive and highway code violations and their mediation by safety orientation in UK drivers. Transport. Res. Part F 1, 107–121]. The results indicated that the Swedish version, like the British original, measures three sources of driver irritation: “progress impeded”, “reckless driving”, and “direct hostility”. Structural equation modelling was used to investigate the relationships between the three sources of self-reported driver irritation, aggressive actions, speed, sex, age, and annual mileage. The models suggested a positive relationship between the amount of driver irritation and frequency of aggressive actions for all three sources of irritation. Female drivers tended to become more irritated than male drivers, while the male drivers tended to act aggressively more often. Surprisingly, drivers who reported that they enjoy fast speeds did not become more irritated than slower drivers when obstructed. The important conclusions are that experienced irritation often leads to openly aggressively actions, and that expression of aggressive behaviours may be a cause of other drivers’ feeling of irritation.     

Beyond general behavioral theories: Structural discrepancy in young motorcyclist's risky driving behavior and its policy implications

While many studies examine the mean score differences of psychological determinants between heterogeneous driver groups, this study reveals a structural discrepancy in a causal behavioral framework. Using young motorcyclists (ages 18–28) as subjects, this study investigates the various roles of key influential factors in determining risky driving behavior. Multi-group analysis of structural equation modeling shows that age and gender are two factors that can effectively distinguish heterogeneous driver groups exhibiting different decision-making mechanisms in shaping their risky driving behaviors. When encountering undesirable traffic conditions, road rage can immediately increase male motorcyclists’ intentions to engage in risky driving behaviors; on the other hand, young female motorcyclists further calculate their perceived risk to determine whether to engage in risky driving behaviors. This result shows that there is a significant link between risk perception and traffic condition awareness for experienced drivers (ages 25–28), but not for younger drivers (ages 18–24). This finding shows that while well-developed theories such as planned behavior and risk homeostasis provide general frameworks to explain risky driving behavior, heterogeneous driver groups may exhibit structural discrepancies that reflect their various decision-making mechanisms. This suggests that, in addition to mean differences, understanding structural discrepancies among heterogeneous groups could help researchers identify effective intervention strategies.     

Analyzing fault in pedestrian–motor vehicle crashes in North Carolina

Crashes between pedestrians and motor vehicles are an important traffic safety concern. This paper explores the assignment of fault in such crashes, where observed factors are associated with pedestrian at fault, driver at fault, or both at fault. The analysis is based on police reported crash data for 1997 through 2000 in North Carolina, U.S.A.The results show that pedestrians are found at fault in 59% of the crashes, drivers in 32%, and both are found at fault in 9%. The results indicate drivers need to take greater notice of pedestrians when drivers are turning, merging, and backing up as these are some of the prime factors associated with the driver being found at fault in a crash.Pedestrians must apply greater caution when crossing streets, waiting to cross, and when walking along roads, as these are correlated with pedestrians being found at fault. The results suggest a need for campaigns focused on positively affecting pedestrian street-crossing behavior in combination with added jaywalking enforcement. The results also indicate that campaigns to increase the use of pedestrian visibility improvements at night can have a significant positive impact on traffic safety. Intoxication is a concern and the results show that it is not only driver intoxication that is affecting safety, but also pedestrian intoxication.The findings show in combination with other research in the field, that results from traffic safety studies are not necessarily transferable between distant geographic locations, and that location-specific safety research needs to take place. It is also important to further study the specific effects of the design of the pedestrian environment on safety, e.g. crosswalk spacing, signal timings, etc., which together may affect pedestrian safety and pedestrian behavior.     

Risky driving and recorded driving offences: A 24-year follow-up study

Permanent individual differences in driver behavior and accident risk have long been under active debate. Cognitive and personality factors have correlated with risky driving indicators in cross-sectional studies, and prospective cohort studies are now increasingly revealing early antecedents of risky behavior and injury mortality in adult age, with connections to stable personality traits. However, long-term stability in driver behavior or accident involvement has not been documented in a general driver population.This study reports 24-year follow-up data from a study that compared the recorded offenses between 134 drivers stopped by the police because of sustained risky driving and 121 control drivers stopped at the same locations at the same time in 1987 (Rajalin, 1994. Accid. Anal. Prev., 26, 555–562). Data were compiled from national driver records and accident statistics for the same drivers again 24 years later, and their yearly mileage and speed behavior was requested in a mail survey. The results showed that the two groups of drivers sampled on one trip a quarter of a century ago still differ from each other. The offenders still have more entries in their driver record, also when adjusted for age and mileage (OR = 1.59, CI = 1.03–2.46), they still report in the survey that they drive faster and overtake other cars more often. The results show that individual differences in driver behavior persist for decades, perhaps for life. However, in this on-road sample, the effect seems to be moderated by occupation which also presumably explains the lower mortality among the offenders during this 24-year follow-up.     

The observed effects of teenage passengers on the risky driving behavior of teenage drivers

The association between teenage passengers and crash risks among young drivers may be due to risky driving behavior. We investigated the effect on two measures of risky driving in the presence of young male and female passengers. Vehicles exiting from parking lots at 10 high schools were observed and the occupants were identified by gender and age (teen or adult). At a nearby site, the speed and headway of passing traffic were recorded using video and LIDAR technology. Teenage drivers drove faster than the general traffic and allowed shorter headways, particularly in the presence of a male teenage passenger. Both male and female teenage drivers allowed shorter headways (relative to no passenger or a female passenger) in the presence of a male teenage passenger, while the presence of a female teenage passenger resulted in longer headways for male teenage drivers. Overall, the observed rate of high risk driving (defined as speed > or =15 mph or more above the posted speed limit and/or headway of < or =1.0 s) for the teen male driver/male passenger condition was about double that of general traffic. In conclusion, the presence of male teenage passengers was associated with risky driving behavior among teenage drivers.     

Driver injury severity outcome analysis in rural interstate highway crashes: a two-level Bayesian logistic regression interpretation

There is a high potential of severe injury outcomes in traffic crashes on rural interstate highways due to the significant amount of high speed traffic on these corridors. Hierarchical Bayesian models are capable of incorporating between-crash variance and within-crash correlations into traffic crash data analysis and are increasingly utilized in traffic crash severity analysis. This paper applies a hierarchical Bayesian logistic model to examine the significant factors at crash and vehicle/driver levels and their heterogeneous impacts on driver injury severity in rural interstate highway crashes. Analysis results indicate that the majority of the total variance is induced by the between-crash variance, showing the appropriateness of the utilized hierarchical modeling approach. Three crash-level variables and six vehicle/driver-level variables are found significant in predicting driver injury severities: road curve, maximum vehicle damage in a crash, number of vehicles in a crash, wet road surface, vehicle type, driver age, driver gender, driver seatbelt use and driver alcohol or drug involvement. Among these variables, road curve, functional and disabled vehicle damage in crash, single-vehicle crashes, female drivers, senior drivers, motorcycles and driver alcohol or drug involvement tend to increase the odds of drivers being incapably injured or killed in rural interstate crashes, while wet road surface, male drivers and driver seatbelt use are more likely to decrease the probability of severe driver injuries. The developed methodology and estimation results provide insightful understanding of the internal mechanism of rural interstate crashes and beneficial references for developing effective countermeasures for rural interstate crash prevention.     

驾驶员风险驾驶行为及影响因素分析

为探究中国驾驶员风险驾驶行为产生的原因及其影响因素,利用修正的曼彻斯特DBQ问卷对349名中国驾驶员进行了问卷调查。经过探索性因素分析(EFA)得到了4因子结构模型,分别命名为认知错误、违规行为、无意失误和记忆力流失,并利用验证性因素分析(CFA)对该模型进行了验证。研究了性别与驾驶行为的关系,结果表明男性驾驶员更容易发生违规行为,而女性驾驶员发生无意失误行为的频率较男性驾驶员偏高。通过变量间的相关性分析,研究了驾驶员的统计学信息、4因子以及交通事故之间的关系,构建了基于Logistic回归的交通事故预测模型,研究表明违规行为和年龄是影响交通事故的重要参数。     

Measurement of driver calibration and the impact of feedback on drivers’ estimates of performance

Recent studies focused on driver calibration show that drivers are often miscalibrated, either over confident or under confident, and the magnitude of this miscalibration changes under different conditions. Previous work has demonstrated behavioral and performance benefits of feedback, yet these studies have not explicitly examined the issue of calibration. The objective of this study was to examine driver calibration, i.e., the degree to which drivers are accurately aware of their performance, and determine whether feedback alters driver calibration. Twenty-four drivers completed a series of driving tasks (pace clocks, traffic light, speed maintenance, and traffic cones) on a test track. Drivers drove three different blocks around the test track: (1) baseline block, where no participants received feedback; (2) feedback block, where half of the participants received performance feedback while the other half received no feedback; (3) a no feedback block, where no participants received feedback. Results indicated that across two different calibration measures, drivers were sufficiently calibrated to the pace clocks, traffic light, and traffic cone tasks. Drivers were not accurately aware of their performance regarding speed maintenance, though receiving feedback on this task improved calibration. Proper and accurate measurements of driver calibration are needed before designing performance feedback to improve calibration as these feedback systems may not always yield the intended results.     

Driver age, car mass and accident exposure— A synthesis of available data

The tendency of younger drivers to be more likely than older drivers to drive smaller cars has been an important consideration in a number of prior investigations of the relation between car size and traffic safety. The purpose of the present study is to quantify this effect on a firmer basis than hitherto by fitting data from seven independent sources to a unified general model. More specifically, when the exposure measures “per unit distance of travel” or “per registered car” are used in studies of car mass effects on traffic safety, the exposure information often does not contain the variable driver age. This work develops a general procedure for disaggregating such exposure data into three driver (or owner) age categories; A₁: 16–24; A₂: 25–34; and A₃: 35 years. Data from the seven sources are fined to the equation

f(i,m) = H_i[1 + G _i(m/900 − 1)]

where m is the ear mass in kg, and f(i,m) is the fraction of cars of mass m which are driven (owned) by persons in the A_i, (i = 1, 2, 3) age category. The form of this equation permits easy comparison of 900 and 1800 kg cars. Those particular masses that have been chosen for illustrative comparisons in earlier work. The seven sets of data are used to derive overall average values of the parameters H₁ and G₁. The data from all seven sources show consistent effects which are summarized in one analytical expression which is well suited for use in future studies of car size effects because it reflects a synthesis of much prior data and it permits sensitivity analyses to be performed conveniently.     

Risky driving related to driver and vehicle characteristics

This investigation was performed to determine relationships between driver and vehicle characteristics and risk taking in everyday driving, as measured by close following in freeway traffic. A total of 12,000 observations were made of headways (time intervals between successive vehicles) in high flow freely moving freeway traffic at two sites, one in Michigan, the other in Toronto, Canada. The headways were measured using a photographic technique which allowed vehicle and occupant characteristics to be recorded, including type of vehicle and sex and seat belt use. For the Michigan observations, the vehicle license number was recorded, from which additional information on the vehicle and owner (usually the driver) was obtained from state files, including the vehicle mass and model year and the owner's age. sex and history of recorded accidents and traffic violations. Shorter headways, corresponding to higher risk, were found for drivers with prior accidents or violations, young drivers, male drivers, drivers with no passengers. and drivers who did not wear a seat belt. Vehicles associated with shorter headways included newer cars and cars of intermediate mass (1600–1900 kg).     

Hurried driving: Relationship to distress tolerance,driver anger,aggressive and risky driving in college students

Being a hurried driver is associated with a variety of risky driving behaviors, yet the mechanisms underlying this behavior remain unknown. Distress tolerance, defined as an individual's capability to experience and endure negative emotional states, was examined as a predictor of hurried driving among 769 college students. Results indicate that after controlling for age, gender, race, ethnicity, the student's year in school, their grade point average, driving frequency, angry driving, aggressive driving as well as other forms of self-reported risky driving; hurried driving was significantly associated with lower levels of distress tolerance. Hurried drivers also reported greater levels of frustration and impatience with other drivers, suggesting that they have difficulty in withstanding or coping with negative psychological states when driving. Traditional traffic safety campaigns that emphasize enforcement may be less successful with these drivers. The need to develop campaigns that address the affective coping abilities that contribute to this behavioral pattern is discussed.     

Less is more: the influence of traffic count on drinking and driving behaviour

Drinking and driving road checks are often organized with either a clear prevention or repression objective in mind. The objective of a prevention strategy is to make as many people as possible believe that police officers are enforcing drinking and driving laws and that drinking drivers will most likely be caught. As such, targeting high traffic count road sites with high-visibility road checks is a priority because it serves to increase awareness of the enforcement activity. An alternative to this prevention approach is the “repression” approach that involves targeting times and places where the highest number of drinking drivers are to be expected. Rather than attempting to affect the subjective chance of getting caught, this approach seeks to increase the objective likelihood of getting caught; the aim is to apprehend as many drinking drivers as possible. Regardless of the chosen strategy, there is a need to understand how traffic count influences drinking and driving behaviour as traffic count may play a role in a police officer's choice of sites for a road check. The objective of this paper is to shed some light on this relationship between drinking and driving behaviour and traffic count. In this paper, data from a roadside survey, carried out in British Columbia in 2003, are used. A two-level logistic regression analysis was carried out with data from 2627 drivers coming from 48 different road sites to replicate a model that was previously obtained with comparable data from a Belgian roadside survey, also carried out in 2003. The present study successfully replicated the findings of the Belgian model, substantiating that the probability for drivers to be drinking and driving significantly decreases with an increasing level of traffic count. This supports the suggestion that drinking drivers avoid high traffic count road sites. The relevance of these findings with respect to organizing preventive or repressive road checks and possible confounding variables are discussed at the end of this paper.     

Convicted of fatigued driving: Who, why and how?

Fatigue is a major cause of road traffic accidents. However, due to the blurred concept of fatigue and the lack of reliable testing devices (cf. the breath analyzer for alcohol levels), it is extremely difficult to incorporate fatigue in operationalized terms into either traffic or criminal law. Even though the Finnish Road Traffic Act explicitly forbids driving while tired, it is done only on a general level among other factors (sickness, etc.) that impair a driver's fitness to drive (Article 63). The present study was done to investigate the circumstances of fatigue driving offenses. From the Finnish Vehicle Administration driver record database we extracted all drivers (N = 768) punished under Article 63 from 2004-2005. Of these drivers, 90.4% committed a fatigue-related traffic offense. Accidents, predominantly single vehicle, were the most common (92.5%) consequence of fatigued driving. Although fatigue-related accidents are thought to be serious, our data shows that most of the accidents (81.6%) did not involve personal injuries. Almost every twentieth driver was punished because his vehicle was drifting on the road. The presence of alcohol or drugs was noted in 13% of the cases. Only 3.1% of the punished drivers officially denied being tired or falling asleep. Young men (≤35 yrs) represented 50% of all punished drivers. Time of day and seasonal effects were clear in this data. This study shows that even without a reliable fatigue detector and unambiguous criteria for recognizing the contribution of fatigue to accident causation, Finnish police and the courts punish a significant number of drivers every year on the basis of fatigue.