The service of public transportation in Indonesia nowadays faces a critical condition, as the competition with motorization becomes harder. Government and operator should provide a suitable and acceptable service quality of public transport to retain the current user as well as to attract new user. To anticipate the future, the exploration regarding many related aspects with service quality is imperative. The aim of this study is to explore the causal relationships among the quality of service, satisfaction, negative experience, and future decisions. Data gathered by questionnaire distribution from two cities, i.e. Bandung and Yogyakarta, is analyzed by employing structural equations modeling (SEM). The result shows a difference level of importance of aspects of service quality among cities, which presents the unique characteristics of each city. The analyses also confirm the causal relationship between the service quality with several other related constructs, i.e. satisfaction, negative experience, and future decisions.

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Public transportation has become more important as natural resources are exhausted and environmental pollution increases. However, there are many factors that interrupt the use of public transportation, including cost, in-out vehicle time, level of service and transfer. To encourage the use of public transportation, local governments have reduced public transport transfer fares, thereby eliminating a major obstacle. However, key issues beyond cost and transfer have a large effect on passenger usage of public transportation. This study estimates the effects of passenger choices at change facilities. This study collected data at Gwangmyeong station in South Korea. The effect on passenger-level change facilities choice consists of change facility user time, route moving time and overlap facilities (path-size). The result shows that the escalator was preferred for increasing route moving time and path-size. The escalator is the most efficient means for passengers to move a long distance through a large transfer system.

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Contemporary Australian stadium developments are transit-oriented, implementing extensive travel demand management measures to curtail car access and promote public transport use. Conventional catchment appraisal techniques are inadequate for exploring the likely performance of a stadium location under such terms. Accessibility modelling offers a more incisive view. This research investigates proposed locations for a football stadium on Australia's Gold Coast, exploring its accessibility via the public transport system for city residents. Ease of access is defined in terms of travel time, considering all the legs of the public transport journey. This also includes time spent either walking to and from public transport stops, or interchanging between services. The results of the accessibility modelling suggest a recent decision by the proponents to locate the stadium at Carrara will be deleterious to future stadium and football team viability.

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Travel survey respondents often over or under-estimate their travel time depending on a number of factors. This research presents two methods of measuring average speed and thus travel time. The traditional method, stated travel times from travel surveys are compared and corroborated against measured implied travel time based on a GPS based floating vehicle study to identify the measurable operating speed. An example of this approach is shown for a survey of two wheelers (bicyclists and electric bike users) in two cities in China. In these cases, survey respondents report up to 32%higher travel times than what is measured on a floating vehicle study, depending on the case. The implication of this is that mode choice models calibrated on respondent stated travel time more than triples the effect of travel time compared with a model calibrated on average GPS speed (and inferred trip travel time).

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Traffic calming schemes are gradually becoming more widespread means of addressing concerns in residential streets. Although there has been a lot of recent research investigating the traffic calming programs, little research has been devoted to examining its decision making process. Asian countries for example Japan and Korea have introduced several traffic calming devices but they have no distinct and methodical study procedure. The objective of this research is to illustrate a comprehensive review of North American traffic calming decision making process practices. The scope of which is to serve as a basis for establishing the process guiding principle to introduce in Asian countries. This research reveals that most of the cities are having a warrant based system to check the suitability of traffic calming device. The result shows that the budget constraint is the most important reason to prioritize traffic calming projects while political intervention is the main drawback of the process.

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This paper proposed a novel transit schedule design model in dynamic transit network with uncertainties. An array of uneven headways for each line is designed to optimize the integrated transit service efficiency and reliability. It is formulated as a bi-level problem, by which the transit schedule can be varied so as to make response to the current demand. The objective of the upper level model is to optimize the integrated transit network efficiency and reliability. The lower-level model is a reliability-based transit assignment model, in which uncertainties from both demand and supply side are taken into consideration. The bi-level problem is solved by applying the Genetic algorithm (GA). Finally, a numerical example is used to show the performance of the proposed model and solution algorithm.

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This paper analyzed the willingness to pay (WTP) for reducing the lost time of railway users in Tokyo Metropolitan Area. A questionnaire survey was conducted to obtain the data for the analysis. Contingent valuation method (CVM) was applied to inquire their WTP in the survey. A statistical method for survival data analysis was applied to estimate the WTP function. As the results of the estimation, some significant factors which influence on the WTP were detected. Meanwhile, the expectation of the WTP was calculated using the estimated function. Then, it became clear that the expectation of the WTP was proportional to the amount of the lost time and that the expectation changed in accordance with the amount of the reducing of the lost time.

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Dramatic increases in the number and weight of vehicles have resulted in severe rutting on flexible pavements. A mechanical-based rutting model was developed to account for material properties changes in the progression of rutting over time and cumulated compressive strains of all layers due to traffic overloading. Nonlinear, viscoelastic, and viscoplastic deformation components of the pavement structures were characterized by theoretical modeling. Laboratory tests were conducted to obtain the essential parameters. A test field road was constructed to validate the prediction model. Results indicated that structural arrangement of pavement layers had a significant influence on rutting performance of the asphalt layer. Permanent deformation trafficked at 20 kph was two times higher than that at 90 kph. Both measured and predicted rut depths were in good agreement. Incorporation of the mechanistic approach in the prediction of rutting was shown to be viable and provided valueable information on the contribution of each layer to permanent deformation in flexible pavements.

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There are two approaches for the pavement analysis, deterministic and probabilistic. Most of pavement analysis are based on the deterministic approach. In order to account the random variations of the material properties within the pavement system, a more realistic method is the probabilistic approach, in which the materials variables are given a mean and variance. The effect of variation layer properties of pavement on surface defections and strains in the pavement system are studied by sensitivity analysis. This is done by using a stochastic finite element based on the perturbation method which is based on the Taylor expansion. The results show the variation of surface deflections and strains in the pavement are related to the variation of layer moduli. Once the probabilistic properties of pavement response are known, the reliability of pavement design can be evaluated.

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The AASHTO Pavement Design Guide provides one of the most commonly used methods of rigid pavement design. One of the drawbacks identified by researchers is, when k (modulus of subgrade reaction) is unavailable and has to be estimated from E (modulus of elasticity), the k-E relationship used in the design gives too high k. This could result in a thin slab thickness in pavement design. This research evaluates five k-E relationships, together with the one used in the AASHTO design guide, to asses their relative performance in calculating slab thickness using the AASHTO thickness design equation. The results of this study concluded that the k-E relationship by AASHTO method is not recommended because of the large errors involved. Among the six k-E relationships evaluated, the equivalent k-E models based on l _k -l _E relationship outperformed the other k-E relationships in its ability to estimate k values that best approximate field measured values.

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Option evaluation systems (OESs) have been extensively used as an effective means to support decision-making on investment and management of road asset in both developed and developing countries over the last four decades. When carrying out the strategy analysis using OESs with dynamic sectioning (called SDS), a nationwide network is typically subdivided into several sub-networks due to administrative or technical needs. However, techniques for doing SDS in such a case have not been well developed. Therefore, the objective of the paper is to present a comprehensive procedure to carry out the SDS for a nationwide road network including sound trade-off analyses of all constituent sub-networks. Although the Highway Development and Management System (HDM-4) is used as an OES in the case study in this paper, the proposed procedure is general enough to allow almost any OESs.

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The principal mode of structural failure for jointed plain concrete pavements (JPCP) is fatigue cracking. The fatigue cracks initiating at the slab bottom under the edge loading condition were thought to be the only mode of failure. However, under certain combinations of exposure conditions and loading, the critical tensile stress can develop at the slab surface, causing the fatigue cracking to initiate from the top. A detailed evaluation of JPCP response showed that top-down cracking may indeed be the critical failure mode in many cases, but the magnitude of fatigue damage accumulating at the slab surface is very similar to that at the bottom of the slab. Therefore, the past practice of considering only bottom-up cracking is not likely to have resulted in significant prediction errors, especially since mechanistic performance models are typically calibrated with field performance data. Nevertheless, for improved design, consideration of both modes of failure is desirable.

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This paper discusses the assessment of road maintenance and network capacity expansion planning, based on network reliability concept. The network reliability could be considered as a user oriented parameter, since it describes the service that the road users might experienced while traveling through a network. The primary arterial road network of Sumatera Island, Indonesia, is chosen to be tested. Several scenarios of network maintenance and capacity expansion were assessed. The considered centroid pairs were the origin-destination pairs with the highest movement of freight and passenger. Results suggest that the network capacity expansion by constructing new roads at certain corridor along central and west coast of Sumatra Island does not necessarily improve the network reliability indices, except for centroid pairs that directly connected to the improved route. On the other hand, the betterment and periodic maintenance program on several road segments might have higher improvement of connectivity reliability compared to the network capacity expansion up to a moderate level of link reliability.

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The increasing of road material demand particularly on aggregate has been followup by finding the new alternative materials. Local materials such as Bantak and Clereng are potentially to substitute current need. Apparently Bantak is having high porosity and abrasion value more than 40%, on other hand Clereng is giving lower abrasion value (± 25%) than Bantak. Therefore, it is essential to study the performance and durability of these materials in AC-WC mixture. To find the durability index, the specimens are immersed around 0 (unconditioned) to 14 days at 60°C and tested by using Marshall and ITS. From the Marshall test, the index values for aggregate variations I, II, and III are 35.01%, 28.11%, and 26.10% respectively, while from ITS test, the indexes are 33.70%, 27.97%, and 25.45% respectively. The best result is variation III as the lowest value because has less of Bantak, which means less porosity and water absorption.

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Exceedingly heavy axle loads to hot mixture asphalt (HMA) can lead to the permanent deformation. It is caused by repetitive traffic load at high temperature. Rutting of these mixes can be predicted by laboratory creep test. The purpose of this paper is to look at some aspects of the effects of fine aggregate physical, chemical and mechanical properties on the creep behavior of HMA. Four types of sand (quarry, river, mining and marine sand) with two conventional binders (PEN 50/60 & 80/100) and four polymer modified bitumen (PM1_76 & PM1_82 and PM2_76 & PM2_82) were studied on hot mix asphalt creep resistance. According to the dynamic creep test results mixtures prepared using fine aggregate that has more angularity, rougher, high shear strength and high percentage of Al₂O₃, presented highest resistance to creep deformation. Also polymer modified mixtures give the best result compared with conventional mix.

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Delay is an important factor in the optimization of traffic signals and the determination of the level of service of a signalized intersection. The paper proposes the modified Webster's formula to estimate the delay of vehicles at pre-timed signalized intersections under mixed traffic conditions. Traffic volumes approaching signalized intersections are classified into four groups: Motorized two-wheeler, Car, Minibus, and Bus. The passenger car unit is estimated by using the multiple regression analysis. Distributions of the saturation flow are developed and proved to follow the normal distributions at three studied intersections. The expectation function method and Taylor series expansion are then utilized to estimate the mean and variance of delay. A comparison between the proposed model and (i) the conventional Webster's model and (ii) observed delays are performed to present the improvements of this model.

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While many developed countries have typically been facing problems related to four-wheeled traffic, developing countries are facing problems related to small motorized vehicles, such as motorcycles. However, very few studies have been conducted to the traffic operation of motorcycles in the existing literature. This study proposes the methodology to estimate the motorcycle unit (MCU) with a consideration of dynamic characteristics of moving vehicles. It expresses the relationship between speeds and occupied spaces with respect to motorcycles and other types of vehicles. A case study is introduced in order to estimate the parameters of proposed formula by using microscopic traffic data at three midblocks in Hanoi, Vietnam. Then, the proposed methodology is compared with previous methods. The results show that the proposed formula represents the best among them. The findings provide useful information that can be used to develop the speed-flow relationship, estimate highway capacity, analyze level of service, and formulate effective traffic regulation and control measures.

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Variable Message Sign (VMS) is one of the major components of intelligent transportation systems (ITS), which is useful for providing real-time information on weather, traffic and highway conditions. In particular, portable variable message signs (PVMS) are very useful in managing traffic events including work zone, special events, and incidents. It is essential that PVMS locations and message operations should be designed with the proper consideration of driver's legibility distance. A variety of factors would affect the legibility distance, such as drivers' travel speed and driver characteristics etc. This study aimed at establishing a functional relationship between legibility distance and causal factors based on extensive field experiments. A specially manufactured PVMS was used for the experiment. A 500-meter tangent segment having 4 lanes (2 lanes for each direction) was selected for field experiments at the Hanyang University at Ansan, Korea. A differential global positioning system (DGPS) in a control vehicle was used to obtain drivers' legibility distances. Data collection and analysis were undertaken to develop an estimation model for the drivers' legibility distances using regression modeling techniques. The proposed model would be greatly useful for ITS designers and planners when making decisions on PVMS locations and message operations for better traffic management.

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This research unveils the factors that affect urban street bottleneck capacity through the use of oblique cumulative plots for traffic analysis on Henry Dunant Road, a busy urban street in Bangkok. Detailed observations on the street reveal that the street bottleneck capacity was affected by several factors such as illegal blocking parked cars, interrupted U-turns from the opposing direction, and interrupted crossover right turns from an access road. In order to analyze the quantitative effects from these factors, four days of traffic data at the study site were collected by video cameras, manually extracted, and plotted using the oblique cumulative curves such that traffic mechanism at the site can be examined by visualizing the changes in flow rates from each different measurement and comparing across observation days. The analysis results show the degrees of how these individual factors affect the street bottleneck capacity.

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Exploring queuing behavior of different types of lanes at signalized intersections is helpful for establishing the methodology for capacity analysis of each lane or group of lanes. In Taiwan's latest revised HCM, straight lanes and un-opposed left-turn lanes at signalized intersections were respectively divided into six types and four types in officially. The field data showed that queue discharge characteristics varied with the lane type and the location of the city, and the nonlinear regression models could accurately describe the discharge behavior of each lane type. Based on these regression models, the influence of the city location factor, f_z, could be used to adjust the queue discharge behaviors among different cities. Therefore, this study collected queue discharge data in several Taiwan cities, performed statistical analyses, and compared the field data to determine f_z. This study found that f_z is an important parameter for comparing queue discharge behavior among cities.

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Conducting traffic control duties at urban intersections significantly affects the operating efficiency of traffic in peak hours. How to make a good personnel allocation plan is a very important issue for urban traffic management. Therefore, this study constructed a manpower demand evaluation model of three objectives and nine criteria based on two-stage questionnaire surveys. The relative weight of the criteria was determined by the analytic hierarchy process (AHP). The generalized score of this evaluation model can be used to measure the need of traffic control manpower for urban intersections. According to this generalized score and a practical rule-of-thumb, this study proposed the personnel allocation principles further. Finally, this study found that the proposed model and principles are feasible by applying to two cases of the Taipei Police Districts.

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The understanding of merging operational quality for expressway is very important to transportation engineers in planning, designing and maintaining the highways. Projected traffic demands along with the estimated facilities requirement to support the traffic are crucial inputs to the planning of infrastructure expansions. In the design context, the understanding of capacity analysis can assist highway designers in justifying the feasible alternative to be implemented. Traffic engineers normally utilize traffic models prediction to anticipate congestion and potential breakdown at critical areas. Through this approach, they are able to develop appropriate countermeasures and route diversion strategies as well as in developing traffic management strategies to solve the congestion on the expressway. Merging flow rates models were successfully developed and validated in these studies. They are needed in order to understand the merging operation at ramp junctions. The models are useful for estimating flow rates in lanes 1 and 2 immediately upstream of the merge influence area.

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This study proposes a modified asymmetric simple exclusion process (ASEP) approach to simulating low-to-high traffic densities, from which the three-phase traffic phenomena are explored. The chronologically-ordered flow, speed and occupancy data extracted from Taiwan freeway's dual-loop detectors are analyzed and tested. The observed traffic features do exhibit free-flow phase, synchronized-flow phase, and breakdown phenomenon, which can also be elucidated by the simulated results with the proposed approach. Paired traffic parameters are displayed by their relations and by their chronological order so that more insightful traffic features are explored.

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This paper presents an approach and a case study to traffic responsive signal control in mixed traffic conditions. Inductive loop detectors are not likely to be a feasible option in many fast growing cities of developing countries due to heterogeneous, often very congested traffic conditions with no lane discipline. Therefore, the approach used in this paper is based on identifying traffic conditions through bus travel time information obtained through direct vehicle to infrastructure communication. The approach is embedded in the MOSCUE framework (multi-objective signal control in urban areas) which allows the decision maker flexible adjustments of the signal controller to possibly changing policy objectives. The feasibility of the concept is illustrated with a case study from Ho Chi Minh City, Vietnam. It is shown that even if only buses transmit travel time data the controller can achieve some improvements in overall traffic performance.

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If the current adaptive cruise control systems(hereafter referred to as ACC) is fitted to vehicles running on expressways, the occurrence of congestion will be relieved by maintaining the appropriate following distance. However, it does not have the function of appropriately controlling starting and following of a vehicle in congestion, so it is considered that once congestion has occurred, ACC is not useful for faster clearing of the congestion. Therefore, in this research an advanced ACC is proposed in which the function of starting and following is added to conventional ACC, and an estimate of the extent to which congestion would be relieved by installing this to vehicles was made based on current traffic data. The results indicate that, for example, when 25% of vehicles are installed with advanced ACC, the congestion volume would be relieved by about 40%. This shows that faster clearing of congestion can be achieved by increasing the use of advanced ACC.

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This paper investigates the effects of motorcycles on traffic operations at signalized intersections. Field surveys are conducted to study the effects of motorcycles on other traffic by examining discharge headway. It is found that the effects of motorcycles may be measured in terms of an increase in the start-up lost time of signal phase. Presence of motorcycles does not affect the saturation headway of traffic. A microscopic traffic simulation is developed so that effects of motorcycles can be taken into account in the planning and management of urban streets. It is found that our software can replicate the discharge headway as observed from the actual data.

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The Advanced Traveler Information System (ATIS) has been applied in many countries because it has been proved as one of potential solutions to solve congestion problem and to improve the quality of driving. Providing drivers with additional traffic information, it is expected to influence their travel decision on route and destination selection, or even on cancellation of the trip. A number of studies have been conducted in order to improve the performance of ATIS in various ways, such as the setting of the system, the content of information, the accuracy of the information, etc. Yet the effectiveness of the system is heavily dependent on the driver's behavior and response to the given information. The behaviors are somewhat unique for specific individuals (cities). The primary objective of this study was to analyze the behavior of drivers in different Southeast Asian major cities; Bangkok (Thailand), Kuala Lumpur (Malaysia), and Singapore (Singapore), pertaining to changing route under influence of traffic information availability and travel situation. Users' characteristics including socio-economic and trip characteristic as well as the responses to traffic information were investigated through Revealed Preference. The results illustrate that the behavior of drivers in the three cities are different pertaining to the factors that affect them to change the route. Their socio-economic and trip characteristics play a role in determining their route changing behavior.

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Travel time is a basic measure in transportation studies. It is used for performance measures of the developed transportation system. Among many other advanced techniques, Automatic Number Plate Recognition (ANPR) has gained lots of intentions because it is a non-intrusive approach and this system do not required any additional vehicle identification need to be installed to the vehicle. In this paper, a new real-time ANPR system is presented. The proposed ANPR system has been developed to suit with traffic environment in Malaysia. The development of the ANPR system consists of several processing steps such as vehicle detection, number plate localization and extraction, character segmentation and recognition. A number of tests were done in order to measure the performance and capability of the developed ANPR system. Based on the results, the system is reliable and robust and its capability to measure travel time indicated that it have huge potential to be use in traffic and transportation studies.

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In Japan, and also in other Asian countries, intersections with very long signal cycle time have been problematic especially form pedestrian viewpoint. This research aims to suggest one technique to solve the problems: two-step crossing system with cycle time reduction, as a new standard of intersection design in Japan and other Asian countries as well. To check the effects of it, an experimental attempt are conducted in a real intersection and analyzed through a video survey and an interview survey. As a result, we revealed how much the effect differs by pedestrian walking direction and that lots of pedestrians accept this kind of experiment and think about the future extension. For future task, installing sound signals and remaining-time indicators, and applying different cycle time will be necessary to make this technique new Asian standard of intersection designing and controlling.

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An uninterrupted facility reflects the interrelation of cause and effect on the traffic volume speed density; therefore, if a ramp of traffic flow is merged into the main line at a merged section, single variables (such as speed or density) change, as well as interaction effects. Thus, this study used temporally- and spatially-continuous traffic data for various traffic conditions in order to find changes to correlations and interaction effects in a speed-density traffic flow model with a merging section. These changes were also analyzed in comparison with other sections. As a result of this analysis, it was found that the downstream section where traffic flows (decelerated by merging) can be depicted with "Greenshields" model and that the spatial transition occurs as traffic flow moves farther downstream. It was also found that the upstream, merge and downstream sections showed heterogeneous traffic flow characteristics, i.e., the free flow speed and the speed change rate versus flow density were different from each other.

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Traffic lights are used around the world to control traffic flow in urban road networks in an efficient way. Especially in higher-ranking road sections of road networks, neighbouring intersections with signal control are normally coordinated between each other in order to serve traffic volume on a high quality level. In periodical time intervals, the coordination of signalised intersections needs to be analysed. In this way, it is possible to identify defects in signal control and to adapt traffic control to changed conditions. In this paper, a method for the “Analysis of Traffic Flow in Coordinated Sections of Urban Road Networks by Application of up-to-date Low-Cost Methods” will be presented. The developed method can be used for assessment of traffic flow as well as for identification of defects in signal control in coordinated road sections. It is a stand-alone solution which can be applied independently from local technical equipment of traffic lights. It is expected that the application of the developed analysis method will contribute to a better quality of traffic flow in urban road networks in European as well as in Asian countries.

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This paper investigates the departure time and route choice problem (DTARCP) for the development of online routing applications in advanced traveler information system (ATIS). The DTARCP is concerned with the problem of determining the best departure time and reliable shortest path simultaneously in stochastic and time-dependent networks. It is motivated by the fact that travelers make these two choices simultaneously for their travel. A new model is proposed for modeling the DTARCP with particular application in ATIS. An efficient solution algorithm is developed to solve the DTARCP. Numerical results based on real-world ATIS are also presented to demonstrate the features of the proposed model and solution algorithm. The computational results suggest that the proposed algorithm could be applicable to the online ATIS-based routing applications in large-scale road network.

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Urban traffic in Phnom Penh is characterized by the high level of mixed traffic with an extremely high proportion of motorcycle. Rapid growth of motorcycle with its behavior in traffic is the main cause of road congestion and accident. Recently, there is also a drastic increase in number of light vehicles including car, pick-up, and van causing a more serious problem on traffic capacity and safety. Firstly, this paper investigates the traffic performance of motorcycle-dominated urban street under the impact of light vehicle, whereby particular observation on how motorcycle responds under different proportions of light vehicle is conducted. Data was collected using videotaping technique. Secondly, the present paper examines motorcyclists' perception on traffic safety issue and the extent to which they involve in traffic accident based on motorcycle driver interview survey. Finally, discussion on how to improve capacity and safety is made.

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For a follower-based service measure to be effectively used for two-lane highway quality of service evaluation, a more reliable follower identification procedure is necessary. Current follower recognition methodologies are based on single critical headway values that may not accurately identify followers since they do not take into account the randomness of preferred tracking headways and drivers' desired speeds. This paper presents an improved, probability-based follower identification methodology that takes both of these factors into account while also considering their variability across different driving conditions. The calculated follower percentage and follower density values were compared with those estimated using the 3-second threshold suggested by the HCM. The proposed methodology estimated more followers, particularly during periods of heavy flow, highlighting the inability of using a single headway value to correctly identify followers. The resulting follower counts have been normalized, making it possible to theoretically identify followers at any given time or driving condition.

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This paper attempts to provide additional insights of using a bivariate ordered probit model to simultaneously examine influential factors that affect injury severity (IS) and collision type (CT) of traffic accidents occurring on intersections of national highways in Japan. The effectiveness of the bivariate model is re-confirmed using a large-scaled traffic accident data. The corrections between error terms of IS and CT are statistically significant, implying that there are some unobserved factors that simultaneously affect IS and CT, but are not well captured in traditional accident surveys. Six types of collisions are dealt with and their influential factors are examined with respect to both primary and secondary parties. A complicated structure of influential factors is clarified, and it is expected that such complexity cannot be properly captured based on the widely applied cross-aggregation method in practice.

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This study has the aim to research on global tendency of road traffic safety development in the whole history of about two decades of Vietnam. For the great deficiency in the related traffic accidents data, it carries out a comparative analysis based on important relevant official legal documents which had great impact on the social life. Together with the more and more serious development of traffic accidents, it seems that there exists a hidden “5- years rule”, by which for each five years, the traffic accidents become so critical that the authorities should re-intensify their efforts at a higher level in an attempt to control this big social problem, while the announced main approaches for traffic safety of Vietnam as “All people” and “Comprehensiveness” are basically not different with international well-known “4-E (Engineering, Enforcement, Education and Emergency)” and “Traffic Safety Stakeholders”.

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A crash is often caused by a series of errors and also attributed to a number of categorical explanatory factors. To explore the key rules that determine the most contributing factors to crash severity, this paper develops a novel genetic mining rule (GMR) model, which accounts for the conflict and redundancy of rules mined. To avoid over-mining caused by unevenly distributed data across different types of accidents, identical numbers of A1-type (fatal), A2-type (injury), and A3-type (non-injury) crash cases drawn from 2003-2007 Taiwan's freeway accident investigation reports are used for the analysis. A total of 39 rules are mined which can achieve an overall correct rate of 74.25% in training and 70.79% in validation, respectively, much higher than those yielded by the decision tree model. Travel period, major cause, collision type and journey purpose are found as the four major contributory factors to crash severity in this study.

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Non-recurrent congestion mainly due to the traffic incident is unpredictable. However, its substantial impact on the traffic flow temporarily reduces capacity of roads and incurs enormous time loss. In order to minimize the economic loss from the congestion, the non-recurrent congestion should be dealt with properly and effectively. This study aims to understand major factors affecting the clearance time using complete 2,647 incident data occurred on freeways of Korea in 2005. Using SEM relationships among various exogenous variables and incident clearance time are explored. The model developed in this study is validated using incident data in 2004. The resulting model provides valuable information for the incident clearance time, which can be utilized to manage the incident effectively.

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This paper aims to investigate the influence of accident related factors on motorcycle injuries on two arterial roads in Bali. Multinomial logit (MNL) models are estimated considering three severity classes such as slight injury, serious injury and fatal injury as response variables using local police data as explanatory variables. The analysis shows that there are four variables associated with motorcycle injuries. Sideswipe accidents involving motorcyclists were 51.7% less likely resulting in serious injuries than slight injuries. In addition, motorcycles collided with other vehicle(s), either motorist/motorcyclist failed to yield and motorcycle at fault were 89.1%, 60.7% and 44% respectively less likely resulting in fatal injuries than slight injuries. Probability analysis shows that a change in 1% of these variables could influence motorcycle injuries between 33% and 34%.

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This study investigates the influence of accident related factors on road fatalities using logistic regression technique. Logistic Regression models were separately developed for fatal accidents considering motorcycles and all vehicles including motorcycles using Bali in Indonesia as a case study. Based on the State Police of Bali Province accident data, seven predictor variables were employed in the developed models. The study found that the odds of fatal accident due to male motorcyclists and motorists at fault were 0.3 and 0.4 respectively lower than for females. Thus, the probabilities of female motorcyclists and motorists were about 79% and 72% respectively contributing more on motorcycle and motor vehicle fatal accidents than males. In addition, age was also significant to influence all vehicle fatalities. Age was accounted for about 50% to influence all vehicles fatalities.

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Past road safety studies have mostly focused on the identification of scenarios involving high accident risk. However, risky scenarios can only describe accident outcomes rather than the real causality. Discussion of driver's cognitive interaction while driving is a necessity for deeper exploration about the nature of accident. To comprehend the entire structure of mental workload, this research proposes a research framework for studying mental models that incorporates task demand and motivated capability. Understanding the contributing factors of mental model and the individual difference in task demand and motivated capability can help evaluate the mental workload. In addition, integrating mental model with accident chain analysis enables exploring information net effect on mental workload. Thus, optimized information can hopefully be defined and provided to drivers in different scenarios without causing additional risk of accidents.

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In general, member countries of the ASEAN with high motorcycle registration have been found to have very high road crash incidence. In the Philippines, every year, more than 600,000 motorcycles have been added on the road. In 2007, the number has reached 2.65 million. There is much to learn from the lessons of the other ASEAN countries which have gone through the experience of having too many motorcycles on the road as they become more affordable but with corresponding alarming problem on road safety. The paper shows that this experience has already begun in the Philippines, and if the trend would continue without any proper intervention, the same fate of its neighbouring countries may likely be replicated.

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The present study aimed at identifying the habitual driving styles and evaluating how these styles connected to drivers' sociodemographic factors as well as speeding and accident experience. In a quota sample of 247 Taiwanese individuals, an exploratory factor analysis combined with a confirmatory factor analysis was conducted to derive five valid constructs including aggressiveness, anxiety, misjudgment, distraction, and unawareness. Moreover, four driving styles were identified and analyzed via a K-means cluster and logistic regression analysis. The analytical results showed that the derived constructs significantly differ on their sociodemographic factors, speeding experience, but not on accident involvement. Moreover, the constructs exhibited distinct impacts on the formation of driving styles while exposure factors were controlled. The heterogeneous driving styles explored in this study could reconfirm the heterogeneity of driver personality and accident occurrence found in past studies. General strategies to the sample population and specific strategies to each driving style were discussed.

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An advisable ‘evidence-based’ strategy to reduce the red-light running should be built upon higher priorities of the driver's behavioral intention to run the red light under the common situations without the public controversies in the future. The purpose of this study is to use Rasch modeling with objective measurement to explore the priorities of the motorcyclist's behavioral intention in red-light running under the common situations. The results indicated that the participants reported higher levels of motorcyclist's behavioral intention in red-light running when there is nobody at night time, they are in a hurry, and they pass by not much heavy intersections; on the other hand, they reported lower levels of motorcyclist's behavioral intention in red-light running when there are passengers in the vehicle, and it is raining. In addition to red light cameras, this study provided traffic safety experts with objective evidence of other possible strategies to reduce the red-light running under the common situations from the behavioral science and Rasch modeling perspective.

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Considering the effects of cohort on aspects of the younger generation will help in understanding the latest decline of the number of fatal accidents in Japan. This study investigated the effects of changes in patterns of age, period and cohort on the number of fatal and injured accidents quantitatively through the use of a wide-ranging set of statistical techniques. We used the number of driving license holders as an exposure value. As a result, cohorts had a strong effect on changes in the number of fatal accidents. However, cohort had little effect on changes in the number of injured accidents. The cohorts born in 1967-71 and 72-76 has a large increasing effect on the number of fatal accidents, and the latest cohort born in 1982-86 has a large decreasing effect. It should be noted that the number of driving mileage per age group is more desirable as an exposure value.

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The urgent need to improve the road accident problem in Thailand is to build up accident knowledge and research base which has led to the establishment of Thailand Accident Research Center. The goals of this establishment are to conduct the accident indepth study to investigate, analyze, and evaluate the mechanisms behind crashes and the incidence of injuries on a continuous basis. The objectives of this paper are to present the findings on the contributing factors of road crashes through accident in-depth study in Thailand. The study involves scene investigation to inspect the accident site and gather all related evidences. Then, all of evidences are reconstructed in order to determine the crash significant factors. The findings of this study summarize different characteristics of crashes encapsulating most of the accident cases in Thailand, which related to motorcycle accidents, behavior of young drivers, road side hazard crashes, and rollover crashes.

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“Grouping” behavior is a unique characteristic of the mixed traffic with the dominance of motorcycles. At two-phased signalized and non-signalized intersections in Hanoi city there are increasingly serious conflicts between vehicles groups, especially between the unprotected left-turn and straight-go groups, thereby reducing traffic speeds and increasing accidents. This study was aimed to investigate the mechanisms of the inter-group interactions and suggest measures to manage the intersections. First, a general analysis was conducted to initially understand the interactive strategies by each group and determinant factors. Then, a gap acceptance model was developed to deeply analyze the gap decision-making process by the left-turn groups and capture behavioral differences between the motorcyclists and car divers who lead the groups. The study found that the total gap, which combines the longitudinal and lateral gaps, strongly influenced the gap decision of both the drivers. Interestingly, the number of motorcycles in the left-turn group could make its leading motorcyclists more aggressive. The leading car drivers appeared to be sensitive to the expected waiting time while the motorcyclists did not.

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Hydroplaning is a major safety concern in wet-weather driving. Grooved tires have been commonly used to improve skid resistance and increase the hydroplaning speed. Tire grooves help in the expulsion of water from the tire pavement contact region by providing escape channels. Past researchers have shown that tire groove spacing, groove width and groove depth affect skid resistance. However, analytical tools are unavailable for highway engineers to evaluate hydroplaning speed taking into consideration basic geometric parameters such as tire groove width, groove depth and spacing etc. The present paper describes a numerical analytical tool to study the effect of tire groove spacing, groove width and groove depth on hydroplaning speed by means of earlier verified analytical hydroplaning modeling for tire having transverse groove pattern, longitudinal groove pattern and combined transverse and longitudinal groove pattern on plane pavement surface are analyzed in this paper.

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In winter in Hokkaido, pavement markings are damaged from snow removal, and every spring, the markings need to be reapplied. The authors propose a system of pavement markings whose recessed design prevents scraping damage from snowplows and whose incorporation of rumble strips increases driving safety. To determine the optimum design for recessed pavement markings, trial installation used two intervals between grooves. Driving tests found that recessed markings with long intervals generate more noise and vibration than recessed markings with short intervals, making the former more noticeable than the latter. It was found that waterborne paints are not durable enough to be used on recessed pavement markings. Spraying of thermoplastic paints were chosen instead. Furthermore, in order to improve of nighttime visibility under rainy conditions by highly reflective beads were used. This paper reports on development of recessed pavement markings that incorporate rumble strips.

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Some fatal accidents occur on two lanes expressway in cold and snow area in Japan and no rigid median strip causes more damage to passenger in cars. It is very important to find effective countermeasures that reduce the number of these tragic traffic accidents. However, general characteristics and factors of traffic accidents on undivided expressway have not been clarified sufficiently yet. We apply a discriminant analysis to traffic accidents data for five years in order to find some crucial factors for traffic accidents especially in snow cold region. Two categories, fatal or serious and slight injury, are used as a dependent variable. On the other hand, weather, road circumstance, and cruising speed are used as independent variables. We also propose some useful countermeasures to reduce the miserable traffic accidents on undivided expressway.

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