Approaching and stopping behaviors to the intersections of aged drivers compared with young drivers

According to the many reports of the traffic accidents, the number of the accidents near the intersections was increased in the cases of the aged drivers. The purpose of the research was to measure the sensitivity of elder drivers through behavioral responses in approaching and stopping to the intersections and to obtain the difference of the responses for braking and stopping comparing with young drivers. In the field tests of real running on experimental proving ground, elder and young drivers were observed their driving behaviors in various conditions of approaching and stopping at intersections. Comparing the results of the elder with the young, the unstable driving behaviors were examined in elderly and they were apt to run fast in approaching the intersection and also stopping rapidly. The rates of deceleration change (Jerk) with braking operation were unstable and the driving behaviors were affected by the environments or conditions of the intersection. These driving performances should be interfered with the traffic flow and exposed to the risk of accidents. If the features of these aged driver's behaviors were clarified better, the more effective driving assistant systems for elderly could be developed based on characteristics of elderly driver's driving performances and their physical and psychological features of driving.     

The relation between driving experience and recognition of road signs relative to their locations

OBJECTIVES: Examine how driving experience and expectations affect the ability of experienced drivers to identify traffic signs--specifically, no right turn (NRT) and no left turn (NLT) at intersections. BACKGROUND: Failure to heed signs is a frequent cause of accidents, and the authors focused on the contributions of experience and expectancy to sign identification. METHOD: Inexperienced and experienced drivers were connected to an eye tracker system and briefly exposed to various traffic scenes. Some of the pictures included an NRT sign at the expected location (on the right), and some included the same sign at an unexpected location (on the left). The same procedure was used with an NLT traffic sign. RESULTS: Experienced drivers identified traffic signs better than inexperienced drivers did when the signs were posted at the expected location but identified them worse than did inexperienced drivers when they were at unexpected locations. CONCLUSIONS: With experience, drivers' expectations regarding the expected location of traffic signs become so strong that violating these expectancies results in more identification errors among experienced drivers than among inexperienced drivers. To optimize experienced drivers' traffic sign identification, signs must be located in accordance with drivers' expectations--specifically, on the right side of the road. APPLICATIONS: When signs are misplaced, crashes can be caused by inappropriate placement rather than inappropriate driving. Highway designers should ensure that their design conforms to standards that shape experienced drivers' expectations.     

Driver behaviour at rail level crossings: responses to flashing lights, traffic signals and stop signs in simulated rural driving

Australian road and railway authorities have made a concerted effort to reduce the number of rail level crossings, particularly the higher risk passive crossings that are protected by devices such as ‘give way’ or ‘stop’ signs. To improve this situation, passive level crossings are often upgraded with active controls such as flashing red lights. Traffic signals may provide good safety outcomes at level crossings but remain untested. The primary purpose of this research was to compare driver behaviour at two railway level crossings with active controls, flashing red lights and traffic signals, to behaviour at the current standard passive level crossing control, a stop sign. Participants drove the MUARC advanced driving simulator for 30 min. During the simulated drive, participants were exposed to three level crossing scenarios. Each scenario consisted of one of three level crossing control types, and was associated with an oncoming train. Mean vehicle speed on approach to the level crossings decreased more rapidly in response to flashing lights than to traffic signals. While speed on approach was lowest for the stop-sign condition, the number of non-compliant drivers (i.e., those who did not stop) at the crossing was highest for this condition. While results indicate that traffic signals at rail level crossings do not appear to offer any safety benefits over and above flashing red lights, further avenues of research are proposed to reach more definitive conclusions. Compliance was lowest for the passive crossing control which provides further support for the ongoing passive crossing upgrades in Australia.     

Effect of driving experience on drivers' decoding process of roadway interpersonal communication

Sixty-three participants (32 novice, 31 experienced drivers) evaluated meanings of road users' signals in 24 traffic situations such as blinkers, headlights, hazard lamps and hand gestures. The traffic scenes were projected with a slide projector in a laboratory. Confidence in answers was also evaluated by using a five-point scale. The signals were classified into three categories: Formal Device-based Signal (Formal Signal), Informal Device-based Signal (Informal Signal), and Informal Gesture-based Signal (Everyday Signal). The total comprehension scores demonstrated that experienced drivers could understand the signals better than novice drivers. There was a large difference in the comprehension scores for Informal Signal between experienced and novice drivers. Novice drivers could understand Formal Signal and Everyday Signal better than Informal Signal. Similar results were also obtained in the confidence scores. Experienced drivers were more confident in their answers than novice drivers. An effect of gender was found in the scores of confidence. The discussion focuses on how driver's skill in interpersonal communication on roads develops in real traffic situations.     

Effect of driving experience on drivers' decoding process of roadway interpersonal communication

Sixty-three participants (32 novice, 31 experienced drivers) evaluated meanings of road users' signals in 24 traffic situations such as blinkers, headlights, hazard lamps and hand gestures. The traffic scenes were projected with a slide projector in a laboratory. Confidence in answers was also evaluated by using a five-point scale. The signals were classified into three categories: Formal Device-based Signal (Formal Signal), Informal Device-based Signal (Informal Signal), and Informal Gesture-based Signal (Everyday Signal). The total comprehension scores demonstrated that experienced drivers could understand the signals better than novice drivers. There was a large difference in the comprehension scores for Informal Signal between experienced and novice drivers. Novice drivers could understand Formal Signal and Everyday Signal better than Informal Signal. Similar results were also obtained in the confidence scores. Experienced drivers were more confident in their answers than novice drivers. An effect of gender was found in the scores of confidence. The discussion focuses on how driver's skill in interpersonal communication on roads develops in real traffic situations.     

Development of a fuzzy logic traffic system for isolated signalized intersections in the State of Kuwait

In a conventional traffic signals controller, the lights change at constant cycle time. In many cities, automatic traffic signals are often based on a constant green-to-red cycle. The time period for green light (or red light) to be on is determined based on a stochastic model. The traditional vehicle-actuated control of isolated intersections attempts continuously to adjust green times. The decision to change green light duration involves fuzzy factors that cannot be precisely determined.The main objective of this paper is to develop a fuzzy logic traffic system that considers the two two-way intersections and is able to adjust changes in time intervals of a traffic signal based on traffic situation level.The proposed system has been applied and tested using real data collected from signalized intersection in Hawalli governorate in the State of Kuwait. Twenty-seven iterations have been done; the results show that the proposed fuzzy logic traffic system provides better performance in terms of total waiting time, total moving time, and vehicle queue. Finally, it can be observed from the results that the proposed system can be used to accelerate the cycle time and to give other phases the chance to gain more benefit from the green time lost.     

Hierarchical control of traffic signals using Q-learning with tile coding

Multi-agent systems are rapidly growing as powerful tools for Intelligent Transportation Systems (ITS). It is desirable that traffic signals control, as a part of ITS, is performed in a distributed model. Therefore agent-based technologies can be efficiently used for traffic signals control. For traffic networks which are composed of multiple intersections, distributed control achieves better results in comparison to centralized methods. Hierarchical structures are useful to decompose the network into multiple sub-networks and provide a mechanism for distributed control of the traffic signals. In this paper, a two-level hierarchical control of traffic signals based on Q-learning is presented. Traffic signal controllers, located at intersections, can be seen as autonomous agents in the first level (at the bottom of the hierarchy) which use Q-learning to learn a control policy. The network is divided into some regions where an agent is assigned to control each region at the second level (top of the hierarchy). Due to the combinational explosion in the number of states and actions, i.e. features, the use of Q-learning is impractical. Therefore, in the top level, tile coding is used as a linear function approximation method. A network composed of 9 intersections arranged in a 3×3 grid is used for the simulation. Experimental results show that the proposed hierarchical control improves the Q-learning efficiency of the bottom level agents. The impact of the parameters used in tile coding is also analyzed.     

Traffic lights detection and recognition based on multi-feature fusion

Many traffic accidents occurred at intersections are caused by drivers who miss or ignore the traffic signals. In this paper, we present a method dealing with automatic detection of traffic lights that integrates both image processing and support vector machine techniques. Firstly, based on the color characteristics of traffic lights, the paper proposes a method of traffic light segmentation in RGB and HSV color space. And then, according to the geometric features and backplane color information of traffic lights, we design an algorithm to remove false targets in images. Moreover, in order to solve traffic lights diffusion problem, we apply a strategy that we first map the candidate regions onto the original image, then using Otsu algorithm re-extract the target region. Finally, HOG features are extracted from the target regions, and recognized by the trained SVM classifier. Experimental results show that the proposed method has relatively high detection rate and recognition accuracy in different natural scenarios, and is able to meet real-time requirements.     

Older driver failures of attention at intersections: using change blindness methods to assess turn decision accuracy

A modified version of the flicker technique to induce change blindness was used to examine the effects of time constraints on decision-making accuracy at intersections on a total of 62 young (18-25 years), middle-aged (26-64 years), young-old (65-73 years), and old-old (74+ years) drivers. Thirty-six intersection photographs were manipulated so that one object (i.e., pedestrian, vehicle, sign, or traffic control device) in the scene would change when the images were alternated for either 5 or 8 s using the modified flicker method. Young and middle-aged drivers made significantly more correct decisions than did young-old and old-old drivers. Logistic regression analysis of the data indicated that age and/or time were significant predictors of decision performance in 14 of the 36 intersections. Actual or potential applications of this research include driving assessment and crash investigation.     

基于行人安全的交通信号灯智能控制算法研究

提出了一种基于深度确定性策略梯度(DDPG, deep deterministic policy gradient)的行人安全智能交通信号控制算法;通过对交叉口数据的实时观测,综合考虑行人安全与车辆通行效率,智能地调控交通信号周期时长,相位顺序以及相位持续时间,实现交叉路口安全高效的智能控制;同时,采用优先经验回放提高采样效率,加速了算法收敛;由于行人安全与车辆通行效率存在相互矛盾,研究中通过精确地设计强化学习的奖励函数,折中考虑行人违规引起的与车辆的冲突量和车辆通行的速度,引导交通信号灯学习路口行人的行为,学习最佳的配时方案;仿真结果表明在动态环境下,该算法在行人与车辆冲突量,车辆的平均速度、等待时间和队列长度均优于现有的固定配时方案和其他的智能配时方案。     

Selective searching while driving: the role of experience in hazard detection and general surveillance

Novice drivers have been found in previous studies to display a limited search of the immediate environment, relative to experienced drivers, when manoeuvring on a dual-carriageway road. The present study investigated whether this reduction in the variance of search along the horizontal plane was a product of less frequent glancing in the car's mirrors. Novice and experienced drivers were observed as they made lane changes in relatively unobstructed conditions and when they needed to move into a lane already occupied by traffic. Novice drivers were found to rely more than experienced drivers upon their internal mirror, even when the lane-changing manoeuvre required information about traffic in the lane best reflected in the external, door-mounted mirror. Novices did increase their use of the external mirror in response to driving needs, suggesting that they did have an awareness of the situation that required inter-weaving with traffic in their destination lane. Their reliance upon the internal mirror may be a product of a habit acquired specifically for the driver licensing examination, in which exaggerated inspection of the internal mirror is regarded as being desirable.     

基于物联网的AI交通管理系统——智能斑马线关键部分的设计与实现

随着人们生活水平的提高和日趋快速的现代化生活节奏，汽车几乎成了每家的必备出行工具，随之出现的就是交通事故数量的剧增。2018年最新交规新鲜出炉（不礼让行人扣3分，罚200元），由此可见人和车的矛盾始终存在。面对众多路口，不间断时间，仅依靠交警自身维持路口秩序，常常力不从心。本系统通过基于物联网的智能监测，对路人闯红灯行为进行自动监视和警告，结合语音提示，智能改变斑马线颜色等措施，在不需要人工介入的前提下实现行人过街的规范管理，减少行人闯红灯现象，降低交通事故发生概率，构建安全和谐的城市交通出行环境。     

广播电视时钟同步发生器的设计与实现

广播电视节目都是经过延时才进行传输的,如果延时没达到同步则会导致信号失帧、音频和视频信号出现不同步的情况,这便需要精确的时钟同步系统来进行时间控制。文章从时钟设计原理出发,深入研究了时钟同步发生器的设计原理,实现了硬件、通信和芯片电路的设计,为广播电视技术维护人员在进行时钟的同步设备选型、维修和系统设计时提供了一定价值的参考。     

Using data mining techniques for optimizing traffic signal plans at an urban intersection

A key problem in traffic engineering is the optimization of the flow of vehicles through urban intersections by improving the timing policy of traffic signals. Current methods of signal control policy are based on the junction topography and prespecified static traffic volumes. However, the actual daily traffic volumes can be affected by many time‐dependent factors making a static policy hardly optimal. In this paper, we induce nonstationary predictive models of traffic flow by applying novel methods of time‐series data mining to the traffic sensors data collected from a signalized intersection in Jerusalem over a period of 3 years. Our methodology for modeling dynamic traffic volumes combines clustering and segmentation algorithms. The results of a case study based on real‐world traffic data demonstrate that a dynamic signal policy using the data mining approach can produce a decrease of about 33.7% in the total waiting time of drivers during 1 year, in comparison to the existing static traffic policy. The resulting savings for this junction only would be about 13,800 driving hours, which are worth of about $52,000 per annum in terms of Israeli economy. © 2011 Wiley Periodicals, Inc.     

A field evaluation of driver eye and head movement strategies toward environmental targets and distractors

A new systems approach for evaluating field performance of drivers is presented in a practical experimental demonstration. The emphasis reflected in this paper is on driver head and eye movement behaviour toward environmental targets and distractors. A unique video technology set-up was designed to record eye and head movements. Simultaneous video-tapings of driver eye/head movements and the environmental scene were time synchronised. Two intersections (one busy and one quiet) were carefully selected and analysed for their static and dynamic visual targets and distractors. A subject made 40 repetitive left-turns alternately at busy and quiet intersections in a naturally moving traffic environment. Both head movement patterns and eye movement frequencies differed significantly between the two intersections. Results suggest that the eye and head movements are highly dependent upon the type of turn configuration, type and frequency of targets, type and frequency of distractors, and traffic control configurations.     

交通灯运行时间自适应算法及其控制系统

城市交通拥堵具有严重的危害性, 直接导致时间延误、能源浪费和废弃物排放增加, 降低居民生活水平. 现阶段, 基于平面交叉路口交通灯切换时间相对固定, 恶劣天气或发生交通事故时路口经常发生交通堵塞的实际情况, 本文提出了一种平面交叉口交通拥堵多方向交通灯运行时间自适应算法, 采取视频图像处理算法判断道路交通拥堵情况, 根据路况设置交通灯的工作时间, 并设计了相应的控制系统. 仿真结果表明, 在高峰期时段, 此自适应算法的车辆通行效率高于传统的交通灯运行时间控制方法.     

Blind and sighted pedestrians' judgments of gaps in traffic at roundabouts

This paper reports two experiments about street crossing under conditions of free flowing traffic, with a focus on modem roundabout intersections. Experiment 1 was conducted at three roundabouts varying in size and traffic volume. Six totally blind and six sighted adults judged whether gaps in traffic were long enough to permit crossing to the median (splitter) island before the next vehicle arrived. Gap distributions and measures of judgment quality are reported. Overall, blind participants were about 2.5 times less likely to make correct judgments than sighted participants, took longer to detect crossable gaps, and were more likely to miss crossable gaps altogether. However, the differences were significant only at the two higher volume roundabouts. In Experiment 2, we evaluated the response of drivers to pedestrians with and without mobility devices (i.e., long canes, dog guides). The experiment was conducted at a single-lane roundabout, a midblock crossing, and a two-way-stop-controlled intersection. Site-specific characteristics appeared to have a greater impact on drivers' yielding than did a mobility device. Actual or potential applications of this research include the development of methods for assessing pedestrian safety and driver behavior as well as identifying intersections that may require modification in order to be accessible to blind pedestrians.     

Where will they turn: predicting turn proportions at intersections

Predicting a driver’s route would be useful for warning a driver of upcoming road hazards, informing about traffic situations, and serving relevant advertising. There are many clues to a driver’s future route, including their past behavior and likely destination. Another clue is the driver’s turn choices at a sequence of intersections. Strung together, the turn choices form a route. This paper develops a basic algorithm, and variations, to predict the aggregate turn behavior of drivers at intersections. Given an intersection with a few different turn options, including the option to continue straight ahead, our goal is to infer the proportion of drivers who will take each option. For ground truth, we use raw turn counts gathered for government traffic studies by our local municipality at 40 different intersections. Our basic turn prediction algorithm is based on the assumption that drivers tend to choose roads that offer them more destination options. This matches our intuition that turning onto a short, dead-end road is relatively rare compared to turning onto a highway “on” ramp. The best performing algorithm predicts turn proportions with a median error of 0.142.     

自推进粒子群的空间同步平行编队控制

平行编队是群体协作控制研究的一项重要内容,而其空间同步,即群体在某一方向上运动步调一致,也是至关重要.本文在耦合谐振子理论基础上,提出了一种全相互作用的变速度自推进粒子模型,设计了一种解决平行编队的空间同步问题的控制方法.该方法通过改变自推进粒子运动速度而引入粒子间空间距离信息,实现了所有粒子沿实轴或虚轴方向的空间同步平行编队,并证明了该方法的收敛性.最后给出了粒子群的空间同步平行编队的仿真例子.     

Design of Regulatory Traffic Light Control Systems with Synchronized Timed Petri Nets

Fixing the phases is one of the common methods to control an urban traffic network. Once a road is filled with a high traffic flow approaching its capacity, the conventional traffic light controller is not able to handle this traffic congestion phenomenon well. In this paper, we propose a novel regulatory traffic light control system to handle such traffic congestion by using synchronized timed Petri nets (STPNs). Three kinds of intersections in an urban traffic network are defined and employed to demonstrate our new regulatory traffic light control system models. Finally, the liveness and reversibility of the proposed STPN models are proven through the reachability graph analysis method. To our knowledge, this is the first work that solves a traffic congestion problem with a regulatory traffic light control technique that is effective in preventing vehicles from entering traffic congestion zones.