General Road Research Articles

Safety in Occupational Driving: Development of a Driver Behavior Scale for the Workplace Context

International statistics indicate that occupational, or work-related driving, crashes are the most common cause of workplace injury, death, and absence from work. The majority of research examining unsafe driver behavior in the workplace has relied on general road safety questionnaires. However, past research has failed to consider the organisational context in the use of these questionnaires, and thus, there is ambiguity in the dimensions constituting occupational driving. Using a theoretical model developed by Hockey (1993, 1997), this article proposes and validates a new scale of occupational driver behavior. This scale incorporates four dimensions of driver behavior that are influenced by demanding workplace conditions: speeding, rule violation, inattention, and driving while tired. Following a content validation process, three samples of occupational drivers in Australia were used to assess the scale. Data from the first sample (n= 145) were used to reduce the number of scale items and provide an assessment of the factorial validity of the scale. Data from the second sample (n= 645) were then used to confirm the factor structure and psychometric properties of the scale including reliability and construct validity. Finally, data from the third sample (n= 248) were used to establish criterion validity. The results indicated that the scale is a reliable and valid measure of occupational driver behavior.

Finite Frequency $H_{\infty }$ Control for Vehicle Active Suspension Systems

This brief addresses the problem of control for active vehicle suspension systems in finite frequency domain. The performance is used to measure ride comfort so that more general road disturbances can be considered. By using the generalized Kalman-Yakubovich-Popov (KYP) lemma, the norm from the disturbance to the controlled output is decreased in specific frequency band to improve the ride comfort. Compared with the entire frequency approach, the finite frequency approach suppresses the vibration more effectively for the concerned frequency range. In addition, the time-domain constraints, which represent performance requirements for vehicle suspensions, are guaranteed in the controller design. A state feedback controller is designed in the framework of linear matrix inequality (LMI) optimization. A quarter-car model with active suspension system is considered in this brief and a numerical example is employed to illustrate the effectiveness of the proposed approach.

Establishment of road traffic crash ＆ traffic injury database

Objective To establish a road traffic crash （RTC） ＆ traffic injury （RTI） database database with scientific and reasonable structure. Methods （ 1 ） A set of scientific and standard RTC＆RTI survey form was made and a software for collection of data on RTC＆RTI developed. （2） The general data on RTI＆RTI of China was obtained from traffic management departments of China and the data of some districts in Chongqing from 2000 to 2006 were obtained. All the data were input into the database for analysis. Results A TRC＆RTI database software V1. 0 was developed based on the survey form. The input items included data about the areas where the accidents occurred, the general situation of the specific accident, the road conditions, the accident causes and responsibilities, the vehicle and the injury to persons. We obtained the RTC and RTI data of China during past 13 years and collected data on 33 987 cases of RTC and 52369 RTI of four districts in Chongqing. The RTC＆RTI database was established. Conclusions The database has involved detailed data of general road crashes and injury as well as individual crash, which provides a good support for further study of RTC and RTI. Key words: Accidents, traffic ; Database management system ; Traffic injuries

3204 自動車を運転する人間の制御パラメータ推定に関する研究(OS7-2 ドライバ行動,OS7 ヒューマンファクタ,オーガナイズド・セッション(OS))

This paper is analyzed of driver's behavior at running condition on general road. The driver model was constructed using feed-back and feed-forward control. By using the driver model, we check possibility to analyze driver's behavior at running condition on general road. From time history of driver model parameters, we examined the validity of this model depending on the surrounding environment.

Disturbance attenuation control of active suspension with non-linear actuator dynamics

This study suggests an approach to design an active suspension controller with non-linear actuator dynamics, which can achieve good ride comfort while respecting safety constraints such as road holding and limited suspension strokes. The procedure includes two steps: design a state feedback ℋ∞ controller for the linear subsystem with time-domain constraints, and then apply the backstepping technique to deal with non-linear actuator dynamics and to derive the control law. The closed-loop system achieves a bounded disturbance attenuation level (the l2 gain), which gives a measure of ride comfort in the case of general road disturbances. Simulation results are provided to show the effectiveness of the designed controller.

Determining Truck Activity from Recorded Trajectory Data

It is a well-known and understandable intention of freight transportation companies worldwide to verify the proper use of their truck fleets. An important and a hardly avoidable step of monitoring truck routes is the visualization of collected route data. To improve the efficiency of visual monitoring, two preprocessing steps are proposed in the paper. The first of these is segmentation of routes into meaningful route sections; while the second is the automatic rendering of route sections to vehicle activity classes. The route segmentation method is based on spatiotemporal features of the trajectory. It is a linguistic approach that can cope with the multiple spatial and temporal resolutions necessary to characterize vehicle/driver activities. These activities range from fairly simple activities to complex maneuvers. Pointers to the detected activities and maneuvers in the trajectory data can be used for indexing purposes. The low-speed vehicle maneuvers and stoppages are looked at in particular. The rendering of route sections to vehicle activity classes is based primarily on the recorded trajectory and speed data, but transportation specific and general road data can be also taken into account. The transportation specific data may include geographic and descriptive data on the actual and regular truck destinations, as well as on roadside accommodations and refueling stations. The general road data provide designations of roads, maximum speed allowed and the socio-cultural structure (e.g., urban, rural) along the roads. The preprocessed truck trajectories could facilitate the detection of traffic rule infringements and suspect driver behavior.

General Road Detection From a Single Image

Given a single image of an arbitrary road, that may not be well-paved, or have clearly delineated edges, or some a priori known color or texture distribution, is it possible for a computer to find this road? This paper addresses this question by decomposing the road detection process into two steps: the estimation of the vanishing point associated with the main (straight) part of the road, followed by the segmentation of the corresponding road area based upon the detected vanishing point. The main technical contributions of the proposed approach are a novel adaptive soft voting scheme based upon a local voting region using high-confidence voters, whose texture orientations are computed using Gabor filters, and a new vanishing-point-constrained edge detection technique for detecting road boundaries. The proposed method has been implemented, and experiments with 1003 general road images demonstrate that it is effective at detecting road regions in challenging conditions.

Design of compact freeform lens for application specific light-emitting diode packaging

Application specific LED packaging (ASLP) is an emerging technology for high performance LED lighting. We introduced a practical design method of compact freeform lens for extended sources used in ASLP. A new ASLP for road lighting was successfully obtained by integrating a polycarbonate compact freeform lens of small form factor with traditional LED packaging. Optical performance of the ASLP was investigated by both numerical simulation based on Monte Carlo ray tracing method and experiments. Results demonstrated that, comparing with traditional LED module integrated with secondary optics, the ASLP had advantages of much smaller size in volume (approximately 1/8), higher system lumen efficiency (approximately 8.1%), lower cost and more convenience for customers to design and assembly, enabling possible much wider applications of LED for general road lighting. Tolerance analyses were also conducted. Installation errors of horizontal and vertical deviations had more effects on the shape and uniformity of radiation pattern compared with rotational deviation. The tolerances of horizontal, vertical and rotational deviations of this lens were 0.11 mm, 0.14 mm and 2.4 degrees respectively, which were acceptable in engineering.

Fahreignung bei Demenz

Physiological changes in cognitive competence in the elderly are clearly different to pathological changes such as dementia. Diagnosing dementia is not to be equated with absolute driving inability. During the course of dementia, the risk of an accident increases significantly. Detailed observation and regular checks serve to determine the appropriate time to hand in the driving licence. The basis of each decision should be a detailed history of the person and his or her immediate family. Attention should be paid to incorrect driving practise, unusual behaviour and uncertainty whilst driving as well as involvement in any accidents. An MMSE score below 24 or a CCT score up to 3 should result in an additional assessment being carried out, e.g. neuro-psychological tests, driving simulator or, if necessary on-road tests performed with specialists. Also helpful is the determination of functional status. Limitations in ADL or IADL function normally indicate an advanced stage of dementia. Due to the progression of the illness, the possibility of handing in the driving licence should be addressed as soon as possible. In this context, it is helpful to consider alternative forms of transportation. Individual wishes and needs must to be balanced against general road safety requirements.

Issues in using model checkers for test case generation

The use of model checkers for automated software testing has received some attention in the literature: It is convenient because it allows fully automated generation of test suites for many different test objectives. On the other hand, model checkers were not originally meant to be used this way but for formal verification, so using model checkers for testing is sometimes perceived as a “hack”. Indeed, several drawbacks result from the use of model checkers for test case generation. If model checkers were designed or adapted to take into account the needs that result from the application to software testing, this could lead to significant improvements with regard to test suite quality and performance. In this paper we identify the drawbacks of current model checkers when used for testing. We illustrate techniques to overcome these problems, and show how they could be integrated into the model checking process. In essence, the described techniques can be seen as a general road map to turn model checkers into general purpose testing tools.

Joint pricing and design of urban highways with spatial and user group heterogeneity

This paper addresses the joint optimization of capacity investments and toll charges imposed on multi-group users in monopolistic private highways within general road networks. A game-theoretic formulation is provided that leads to a nonconvex bilevel program. The proposed modeling framework handles several complex issues raised in realistic applications, such as regulations on the levels of tolls and service, and the discrete nature of highway capacity, using a genetic optimization technique. Real-application results show the importance of considering the spatial heterogeneity of prices, and the tradeoff between investments and pricing strategies in regulated private highways.

Combining Multiple Algorithms for Road Network Tracking from Multiple Source Remotely Sensed Imagery: a Practical System and Performance Evaluation

In light of the increasing availability of commercial high-resolution imaging sensors, automatic interpretation tools are needed to extract road features. Currently, many approaches for road extraction are available, but it is acknowledged that there is no single method that would be successful in extracting all types of roads from any remotely sensed imagery. In this paper, a novel classification of roads is proposed, based on both the roads' geometrical, radiometric properties and the characteristics of the sensors. Subsequently, a general road tracking framework is proposed, and one or more suitable road trackers are designed or combined for each type of roads. Extensive experiments are performed to extract roads from aerial/satellite imagery, and the results show that a combination strategy can automatically extract more than 60% of the total roads from very high resolution imagery such as QuickBird and DMC images, with a time-saving of approximately 20%, and acceptable spatial accuracy. It is proven that a combination of multiple algorithms is more reliable, more efficient and more robust for extracting road networks from multiple-source remotely sensed imagery than the individual algorithms.

Nonnegative Pareto-Improving Tolls with Multiclass Network Equilibria

Congestion charging schemes are considered to be Pareto-improving if they lead to an improvement in system performance while ensuring that no user is worse off than in the situation without any tolling intervention. Anonymous nonnegative Pareto-improving charging schemes are considered in general road networks with multiple user classes, each valuing time differently. Mathematical programming models are proposed for finding a Pareto-improving scheme with heterogeneous users. The properties of the scheme are further analyzed, and the existence conditions are consequently established.

Indian Bus Rapid Transit Systems Funded by the Jawaharlal Nehru National Urban Renewal Mission

This paper reviews the planning, implementation, and initial operation of bus rapid transit systems (BRTSs) in India. The initial four cities that received funds under the Jawaharlal Nehru National Urban Renewal Mission (JnNURM) are reviewed: Ahmedabad, Indore, Jaipur, and Pune. JnNURM is a Government of India (GOI) program to support state and local investment in urban development. GOI also adopted a National Urban Transport Policy (NUTP). Indian states and municipalities are required to follow NUTP rules and regulations, including clear incentives for the implementation of public transport systems and nonmotorized infrastructure projects, as opposed to general road construction or expansion projects. This paper describes relevant characteristics of the BRTSs being implemented in each city and provides comments on planning, design, and institutional arrangements. The projects are an important departure from traditional urban transport practices in Indian cities: they prioritize the use of public transport and nonmotorized modes. Nevertheless, this preliminary survey suggests that in most cases a strong focus remains on infrastructure, while other elements of BRTSs receive less attention. As a result, the full potential of BRTSs is not necessarily attained. Regarding planning activities, it is noted that demand estimation and operations design could have been more elaborate. This paper provides general recommendations for planners, decision makers, and funding agencies in an effort to improve the state of the practice in India and other developing countries.

Asymptotic traffic dynamics arising in diverge–merge networks with two intermediate links

Basic road network components, such as merging and diverging junctions, contribute much to formation and propagation of traffic congestion. However, in contrast to extensive studies of traffic dynamics on a road link, little is understood for those on a road network. In this study, we provide a comprehensive analysis of asymptotic traffic dynamics arising in diverge–merge networks with two intermediate links with first-order kinematic wave models. In addition, traffic demand at the origin and traffic demand at the destination are constant and maximum, and the proportion of vehicles choosing an intermediate link is constant. First, we examine all possible asymptotic stationary states and the sufficient and necessary conditions for their existence. With an example, we find that non-stationary states can include damped (DPO) and persistent periodic oscillations (PPO), and present an equivalent dynamical system that can be used to distinguish these two types of oscillations. This study can be a springboard for better understanding of traffic dynamics, especially formation and propagation of traffic congestion, on general road networks.

Three-Dimensional LiDAR Data Classifying to Extract Road Point in Urban Area

The Light Detection and Ranging (LiDAR) system is one of the best ways to accurately and effectively gather 3-D terrain information. However, it is complicated to process the LiDAR cloud data due to its irregularity and large number of collected data points. This letter proposes a novel method to automatically extract urban road network from 3-D LiDAR data. This method uses height and reflectance of LiDAR data, and clustered road point information. Geometric information of general roads is also applied to correctly extract road points group. The proposed method has been tested on various urban areas which contain complicated road networks. The results demonstrate that the integration of height, reflectance, and geometric information of roads is a crucial factor that distinguishes the proposed method in its ability to reliably and correctly classify road points.

도로교통소음의 전파특성 및 영향

This study was performed to investigate propagation characteristics and effects of road traffic noise generated from vehicles. Noise levels of expressway and general road were measured at four points in a straight line based on distance from the road, and analyzed. The average noise level of expressway was 78.9 dBA at 5 m, 76.4 dBA at 10 m, 72.0 dBA at 20 m, 69.0 dBA at 30 m. That of general road was lower about <TEX>$3.1{\sim}3.5\;dBA$</TEX> than that of expressway. There was no significant difference in distance attenuation between expressway noise and general road noise. The farer the distance from source is, the more the attenuation is. The influence range of noise is assessed by noise environmental standards or road noise limits. Noise levels of the time zone were measured at a boundary line of apartment to grasp noise variation by time. The time zone of lowest noises was <TEX>$3{\sim}4$</TEX> a.m. and that of highest noise was <TEX>$8{\sim}10$</TEX> a.m. Data recorded on tapes were analyzed to understand the characteristics of frequency because these characteristics are important factors to plan the noise reduction measures, namely path measures.

Oscillatory Traffic Flow Patterns Induced by Queue Spillback in a Simple Road Network

We study in this paper some consequences of queue spillback in a simple road network with a steady demand and provide exact formulas for traffic flow patterns. This one origin-destination pair, two-route network contains a diverge and a merge, and the interaction of queues formed at the merge produces several interesting traffic flow patterns, of which two types of oscillatory solutions are of particular interest. One of the oscillatory solutions is decaying, and the other is perfectly periodic. The latter resembles the stop-and-go pattern found in real-world traffic. Because a general road network usually contains many components like the simple network studied here, interaction of queues at junctions provides an alternative explanation to the formation of stop-and-go traffic.

COST BENEFIT ANALYSIS OF SPEED LIMIT REGULATION FOR HIGHWAYS IN JAPAN

In Japan, the evaluation procedure for infrastructure investment projects have been developed well in past ten years, while the evaluations of regulatory provisions are yet to be implemented in spite of OECD recommendation for applying cost benefit analysis (CBA) to regulations. One of the candidate regulations for applying CBA is speed limit regulation since speed limit is set by police agencies without any objective analysis, and the ongoing reform process in road sector is considering relaxation of speed limit in general trunk roads as an alternative policy option. This paper proposes an analytical framework based on CBA and make an attempt to apply the framework to objectively evaluate the resulting costs and benefits due to relaxation of regulated speed in one expressway route in Japan. The result of analysis demonstrates that a net positive benefit can be achieved by upgrading regulated speed.

Statistical Threat Assessment for General Road Scenes Using Monte Carlo Sampling

This paper presents a threat-assessment algorithm for general road scenes. A road scene consists of a number of objects that are known, and the threat level of the scene is based on their current positions and velocities. The future driver inputs of the surrounding objects are unknown and are modeled as random variables. In order to capture realistic driver behavior, a dynamic driver model is implemented as a probabilistic prior, which computes the likelihood of a potential maneuver. A distribution of possible future scenarios can then be approximated using a Monte Carlo sampling. Based on this distribution, different threat measures can be computed, e.g., probability of collision or time to collision. Since the algorithm is based on the Monte Carlo sampling, it is computationally demanding, and several techniques are presented to increase performance without increasing computational load. The algorithm is intended both for online safety applications in a vehicle and for offline data analysis.