A study of traffic at a signalised intersection under high throughputs should gain better understanding on traffic characteristics and direct to better management strategies for city traffic during peak periods. This study explores an analysis approach by applying restricted stop-line counts under high throughputs from the existing system as inputs based on analytical model to evaluate operation performance of an intersection. Adopting the analytical model in optimisation, the preliminary findings shows the different levels in degrees of saturation leading to distinct interpretations of that between the adaptive system and the analytical model, which might be the results from the detector positions of input volumes, the variations in cycle lengths and the difference of algorithms. Further study in the correlation of the degrees of saturation as the performance measure calculated by the adaptive system and the analytical model via controlling signal timing in the model could provide better comparable values.

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In the state of practice, traffic operators require dynamic traffic information in order to make decision to choose the suitable traffic operational plan that could mobilize traffic safer and with less travel delay. Data from conventional point detection system is widely available for determining travel time. Nonetheless, the penetration of detector stations is directly correlated to the accuracy of estimated link travel time. The theoretical as well as practical challenge is the improvement of accuracy of estimated travel time using available or lower level of data from point detection system. This paper aimed to propose on-line microsimulation to be an alternated method for estimating link travel time on expressway with low density of detector stations. The results from the study show that the proposed method is able to represent link travel time on both traffic conditions when implement on expressway with low density of detector stations or long links.

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This study attempts to explore empirically how gross vehicle weight of following vehicle and size of leading vehicle will affect the driver behavior in controlling their speed under different compositions of leader follower pairs. A large sample of traffic and vehicular data for various vehicle types were obtained continuously using a weigh in motion based transport data collection system installed at Federal Route in Malaysia. Then, statistical analysis was applied to explore the driver behavior in controlling the speed in a car following situation from two different perspective: driver s visual input and vehicle dynamics capability. The main findings of this study are when we incorporate the vehicle dynamics capability in a car following situation, the GVW of following vehicle and the size of leading vehicle were significant sources of variation in following vehicle speed and relative speed, and their interaction influence the driver behavior in controlling the speed.

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The signal change and clearance intervals, more specifically the all-red times, are often set longer than necessary in Japan. Too long all-red times not only increase lost time but also may induce aggressive pass and lead to safety drop. Hence, the objective of this study is to investigate the impacts of intersection geometry, signal control, and traffic conflicts on driver's start-up behavior during the signal change and clearance intervals. By using extensive field data, stochastic models are developed for estimating the distributions of starting response time (SRT) and acceleration rate of the entering vehicles. A numerical examination is performed to explore the possibility of reducing the length of all-red times when the aforementioned impacts on start-up behavior are incorporated into the calculation procedure. Conclusions support that the minimum required all-red times can be reduced by 1 second.

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Traffic patterns and the associated phase transitions for pure and mixed traffic are explored in this study. Local traffic parameters are defined in a spatiotemporal (3-D) domain so that the cellular automaton (CA) modeling can precisely capture the traffic features. Refined CA simulations are performed under pure and mixed traffic scenarios on a multilane stretch where virtual detectors are placed to measure the 3-D traffic parameters. It is found that the proposed measuring techniques with refined CA modeling can copiously explore the local traffic patterns with associated phase transitions in both upstream and downstream of a bottleneck. Finally, a comparison of the local traffic parameters with the global counterparts is also presented.

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The objective of this research is to evaluate travel time estimation techniques for offline and online applications using traffic speed. Four offline methods were used to convert speed into travel time for each link, namely mid-point, section average, weighted section average, and San Antonio. Two methods of link travel time aggregation into route travel time are instantaneous and timeslice. The estimated travel times were then compared with the actual travel time collection from 1,632 vehicles. The results indicate that the accuracy depends on time period. Considering route travel time, the timeslice method gives slightly better accuracy than instantaneous method. Comparing the offline and online travel time estimation, the two methods yield similar accuracy. The findings imply that the practical travel time estimation may need several methods suitable for each time period. The improved estimation can increase the accuracy over a single method, decreasing the MAPE from 14-20% to 11%.

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Although several safety countermeasures such as reforming intersection layouts have been implemented, methods to evaluate their effects prior to installation has not yet been established. One of the important safety issues at signalized intersections is the interaction between left-turning vehicles (left-hand traffic) and pedestrians/cyclists. This paper aims to analyze and model the trajectory variations of left-turning vehicles. Vehicle trajectories are collected at several signalized intersections with various traffic and geometric characteristics by video observations. The analysis reveals a significant variation in trajectories depending on intersection angle, number of exit lanes and vehicle type. For modeling individual vehicle trajectories and their distribution, the Euler-spiral-based approximation methodology is applied. Model validation showed that estimated trajectory distributions explain well the spatial maneuver of left-turning vehicles.

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In India, signalized intersections experience heavy and non-homogeneous traffic flow. Traffic model must consider the varying characteristics of all the road users to effectively design and efficiently manage the signalized intersections. An evaluation reveals the applicability of HCM's signalized intersection model for an Indian signalized intersection. The evaluation revealed that the model suffers from serious lacunae when applied to the Indian context. Measures are proposed for the modification of the model, and factors are developed based on proposed modifications in order to make it more suitable for Indian conditions. The factors evaluated are the lane width adjustment factor and passenger car equivalency factors. Mean right-turn width used is 3.6 m while the width provided was 3.3m. Equivalency factors for motorized two-wheelers ranged from 0.4 to 1.3 and for motorized three-wheelers from 5.6 to 9.1. In terms of pedestrian safety, LOS of the intersection is not acceptable.

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Because of right-of-way constraints and safety concerns, on-line linear bus stops with no provisions for buses to pass each other can become the only practical means for passenger services in exclusive bus lanes on urban arterials. How to improve the capacities of bus lanes with this type of stops and accommodate demands by bus companies for a greater access to bus lanes is a pressing issue for the transit authority in Taipei, Taiwan. To provide a decision-support tool to address these issues, field data were collected and used to calibrate a simulation model. The model was then used to examine the relationships between capacity and its influencing factors. This paper discusses the findings of the simulation analysis. It also presents an easy-to-use tool that can enhance capabilities of transportation professionals for capacity and level-of-service analysis.

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In traffic management, it is essential to know the location of not only existing bottlenecks but also potential ones. In this paper, we propose a method for estimating the probabilities of latent bottlenecks as an alternative carrying capacity index for basic (access-controlled) road segments. The capacity of each road segment must be compared, as bottlenecks will occur at the segment having the least capacity. Accordingly, this paper 1) focuses on successive "drift" and "adherence" in congestion queuing, which is observed in association with traffic accidents, and 2) presents a stochastic model using hierarchical Bayesian estimation assuming that adherence sites are those having the smallest capacity. The paper identifies 20 events on 8 expressways as drift and adherence phenomena based on velocity contours measured by traffic detector data, and conclude that the proposed method has potential for description of probabilities of potential bottleneck site by geometric design.

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Mixed traffic flow is the popular problem now, not only in Vietnam but also in almost developing countries. With the mix traffic flow, we have to consider many problems in traffic control and traffic safety, especially in the cases of some countries that private vehicle ownership increase very quickly. This study was conducted to analyze the change in motorcycle driver behaviors with the progress of urbanization and motorization, the observations is inside intersections between left-turn groups and straight-go groups. From the analysis in this study, the results show the changes of driver behavior in case of one popular city in developing countries - Hanoi. This study also conducted the analysis about the relations between group behaviors and conflict situation inside intersection, from that propose some suggestion in traffic control measures and policies for mixed traffic flow

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The waiting time at the stop line, one of the factors affecting the gap acceptance behavior, was investigated in this study. The study focused on the u-turn movement of passenger cars at midblock median openings. The statistical analysis was conducted to judge the effect of the waiting time. The analysis results showed that the waiting time of more than 30 seconds would frustrate the drivers to accept the significant smaller gap than the drivers facing smaller waiting time at the 90% confidence interval. The critical gap parameters were also estimated by the classical regression method. The results showed the critical gap of 4.3 seconds and the follow-up time of 3.4 seconds. The capacity models showed the maximum u-turn capacity of 1,060 pcu/hr. The u-turn traffic control and management at median opening was recommended for safety purpose, especially when the u-turning vehicles might face the long waiting time.

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The perception response time of drivers is one of the most important human factors that have significant influence on driving safety. This is the only parameter that unites all car-following models. Some early literatures dealt this parameter as a constant; however more recent investigations have shown that such assumption might not be valid. This paper reports an investigation conducted on the response time of drivers based on vehicle trajectory data collected from test track experiments conducted in Japan using RTK GPS receivers. A new method was proposed to estimate time-variant response time under car-following situations incorporating some important features of car-following behavior such as perception threshold of drivers. The response time data computed using the method was analyzed to investigate inter-personal and intra-personal variations and influence of driving conditions on the response time. The investigation revealed some important features of human driving behavior.

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The basic model of traffic operations at signalized intersections is based on the assumption that when a signal changes to green the flow across the stop line increases rapidly to saturation flow rate, which remains constant until either queue is exhausted or the green period ends. In recent years, this assumption has been challenged by some field observations in Taiwan and USA. These observations showed marginal increase in queue discharge rate along the queued vehicles's position. This paper investigates queue discharge behavior at signalized intersection based on video data collected from one of the busiest at-grade intersections. The mehods proposed in the HCM (2000) and ARR 123 to estimate saturation flow rates were assessed against field observations. The results from field observations were similar to those observed in Taiwan and USA., whereas the micro-simulation results went against some common perceptions that believed micro-simulation under represents queue discharge rate.

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This study tackles several expressway traffic flow and driver behavior issues observed in Philippine expressway. Expressway management concepts, namely, speed regulation, vehicle spacing, and lane management are outlined and discussed. Speed and headway analysis are performed. Appropriate speed limits and schemes to achieve lane management and checking vehicle spacing to enhance expressway flow safety are recommended.

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Travel time and delay studies are used to evaluate traffic conditions, determine levels of service and to plan for improvements. Transportation planners and engineers of the Metro Manila Development Authority or MMDA still employ the manual or stop watch method using a test car in obtaining travel time and delay data. Thus, it is necessary to develop and demonstrate a more efficient method using tools for assessment of road traffic conditions. This paper presents a Geographical Positioning System or GPS based travel time and delay survey and data analysis methodology. It presents the development and application of a methodological framework and also data analysis and presentation through the use of digital maps. The use of GPS in this research provides fundamental inputs towards the development of a probe car system for use in travel time and delay studies in the Philippine cities.

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Many researches have analyzed the characteristics of car traffic flow. However, there are limited studies focusing on mixed traffic flow which is very common in developing countries. In a mixed traffic flow, the behavior of cars can be considered as lane-based movement. But motorcycles have non-lane movement because they change their direction and speed very often. Therefore, the paper aims to investigate the mechanisms of interactions between motorcycles in their non-lane movement. This study plan to develop a new approach to describe dynamic movement of motorcycles based on social force approach that is commonly applied to pedestrians. Microscopic data collected from video images taken in a road intersection of Hanoi, Vietnam was used for model validation. Parameters were estimated by using SPSS software with non-linear regression method. The result shows that proposed approach can make reasonable prediction of the histogram choice of speed and direction of dynamic movement.

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In Southeast Asia, motorcycles constitute a substantial portion of road traffic. Thus, a passenger-car-oriented traffic control system cannot operate effectively, and traffic efficiency is decreased. To achieve a sustainable and environmentally friendly society, a traffic control system suitable for mixed traffic including motorcycles is highly necessary. Although some traffic policies targeting motorcycles have been implemented, the criteria for implementing them are still unclear. Indeed, the characteristics of motorcycle-dominant traffic flow are not well understood. Thus, this study attempts to qualify the effect of motorcycle-oriented traffic operations and find the criteria for implementing them on the basis of detailed investigations of mixed traffic flow with motorcycles in various cities with differing traffic conditions. The results show that (1) unclear definition of traffic lanes may severely decrease the efficiency of traffic flow and (2) the most effective traffic scheme varies with traffic conditions.

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Highway Capacity Manual (HCM) of USA provides techniques for evaluation of capacity and quality of service of any facility. Studies have shown that these techniques have limited application for heterogeneous traffic situation prevailing in the developing world. As motorcycles are found in large numbers on the urban roads of developing countries; the present study tries to determine their effect of on the capacity of four lane urban roads. The study was carried out in Songkhla province of Thailand, where speed-volume relationship was used for capacity estimation. It was found that similar to the study carried out in India, the capacity of four lane urban roads in Thailand increases with the increase in percentage of motorcycle in the traffic stream. However, though the estimate of capacity was very close to that recommended by the Indonesian highway capacity manual, it was different from the estimated values for similar traffic situation in India.

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This paper formulates dynamic travel time models under density-speed equilibrium states through a statistical approach. The dynamic travel time models are formulated by assuming that travel times are determined by the distribution of the traffic stream condition with respect to either location or time. Then, this paper shows that traffic propagations can be explicitly expressed by a function of a dynamic travel time model. In density-speed equilibrium models, such as the LWR model and the proposed dynamic travel time models, the vehicular speed is instantly adjusted to the density, regardless of the speed of the subject vehicle. As a result, vehicular accelerations in density-speed equilibrium models do not always fall within a feasible region of the vehicular performance. In order to formulate the actual traffic behaviors regarding vehicular accelerations, this paper proposes a non-equilibrium traffic flow model (i.e., continuum car-following model).

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Continuous flow intersection is one of the unconventional intersections which are displaced the right turn bay to the opposite side of the oncoming through traffic called "CFI Leg". The Signals at the main intersection and the sub intersection are operated by two-phase fixed time signal controllers which are coordinated to provide smooth traffic flow. The Distance between the main intersection and the sub intersection is one of the main factors that influences to the capacity of CFI. In addition, it also directly affects to accessibility to the area near the intersection and the cost of CFI construction. Using VISSIM micro simulation, distances between main intersection and sub intersection for different traffic conditions were depicted. Moreover, by applying that into the case study, it was shown that 2 - legs and 4 - legs CFI options are good solutions for solving traffic problem in Khon Kaen City Gate Intersection.

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Arterials in metropolitan cities are expected to provide mobility to high volume of traffic. Realistic understanding of traffic flow behaviour for such vital urban roads is essential for traffic operation planning and management for ensuring desired level of service. Metropolitan cities in India carry variety of vehicles with varied static and dynamic characteristics with predominance of two wheelers. The interaction in the midblock section between different types of vehicles significantly varies with the flow rate and therefore has varied effect on the equivalency of vehicle and the service volume. In present study, the traffic characterization on dynamic scale is carried out by considering two wheeler and car as reference vehicles. Speed-flow-density relationships are developed using dynamic vehicle equivalent factors. The results are compared with the static passenger car equivalent values and corresponding capacity for the selected arterial.

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This study presents a discussion on the vulnerability of motorcycle riders to various road environment factors. The environment factors included in this study are traffic flow and road crashes, weather condition, floods, vehicular emission, noise and alertness level. Initial analyses on the impact of these factors are presented. This study clearly discussed the potential effect of these road environment factors to motorcycle riders.

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With increasing urban traffic flows and increased congestion, the question of design modifications and intersection reconstruction is a common problem for urban traffic managers. In this paper we compare and evaluate the design of a roundabout and intersection in the Norrkoping city, Sweden. The intersection has been simulated with the traffic microsimulation program Aimsun, with observed data from afternoon rush hours traffic. A roundabout, a signalized intersection design and a bowtie intersection design have been proposed and evaluated using results from the simulation. The results from the simulation study indicate that a roundabout design performs better in terms of the travel time compared to a traditional signalized intersection design. A hybrid version of the roundabout and the signalized intersection, a bowtie intersection, shows better performance in terms of travel time passing the junction than both the roundabout and the signalized intersection.

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This paper proposes a new freeway traffic management scheme, which takes advantage of vehicular sensor network and V2V(Vehicle to Vehicle)/ V2I(Vehicle to Infra) 2-way communication environments of the ubiquitous transportation system. The proposed scheme pursues to maintaining traffic flow stability to prevent from or at least delay the flow breakdown and as a result, to maintaining the productivity. Speed control strategies according to the traffic flow states were proposed. Simulation testbed was built for simulation experiments. The simulation results showed that the proposed speed control algorithm significantly improve traffic flow condition of the simulation network. But it fails to prevent from getting congested when flow level increases although it works well to a certain level of flow. The speed control for the congested state should be incorporated in the proposed algorithm, which remains as a further research

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Traffic signals optimise efficiency and safety at intersections by separating conflicting traffic movements in time. To achieve the same vehicle throughput in a reduced signal cycle time, often free left turns are provided for left side driving traffic. The current study intends to evaluate the impact of these free left turns on the traffic behavior by i) measuring their existing capacity utilization and ii) establishing the various factors influencing their performance. Queue lengths and travel times of the left turning vehicles are taken as the indicators of their performance. VISSIM software is used for micro-simulation of traffic and from the results obtained, regression models are developed for queue lengths and travel times. Also, effect of a signalized left turn in place of a free left turn is estimated in terms of the alteration it causes on the queue lengths and travel times of left turning vehicles.

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Currently, various control techniques and systems are used in tollgates as tollgate booth control and Hi-Pass systems have been installed and expanded. This trend has caused significant changes to traffic environment of the tollgate section. For improvement efficiency of various target techniques for tollgate, the characteristics of tollgates should be analyzed first. Therefore, in this study, the field survey and the analysis were conducted to examine the characteristics of closed-type tollgates after division of the target tollgates into the main line section and the interchange section. The service time and the arrival rate were calculated according to the type of each tollgate. Based on the calculation, the goodness of fit test was conducted, which led to the conclusion that the arrival rate depended on the negative binomial and the Poisson distribution while the service time followed the log-normal distribution.

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This research explored the effects of detector setback and controller settings under different speed and volume levels. The purpose of this research was to provide a better understanding on how these actuated traffic signal control parameters can be optimized towards a better performance under different traffic conditions. The results of this research showed that there is a wide range of different parameter combinations that can yield statistically similar results, whereas certain settings can cause significantly poor performance compared to the best one observed. In general, the detector setback and the extension time are critical for lower volumes, extension time plays the biggest role for higher volumes and minimum green time does not generally have a significant effect, except for very low volumes. As volumes are higher, the range of acceptable combinations is wider. There are certain settings that can be used unchanged for different volume and speed levels as safe choices.

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Ramp metering has been proved to be an effective measure of relieving freeway congestion, and it also owns many other benefits such as reducing total vehicle travel time, reducing automobile emissions and so on. This paper tries to develop one ramp metering algorithm which could also take emissions reduction into account. The algorithm occupies two objectives, the primary is to minimize total vehicle travel time, and the secondary is to reduce ramp emissions as much as possible. According to the statistical analysis result, this paper gets some conclusions that the density based ramp metering algorithm is effective in reducing the total vehicle travel time and could reduce on-ramp emissions and queues a lot more than ALINEA strategy. Especially, on large uphill gradient condition density based algorithm could reduce the total emissions much more than ALINEA algorithm.

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In today's road maintenance, the traffic distribution in short periods of time such as in the morning or evening peak is necessary to determine. The aim of this study is to propose the link performance function (BPR function) that focuses on such short lengths of time and the improvement of the accuracy of the BPR function that considers the vertical inclination on the road. The traffic condition was measured in the morning and evening. The relationship of actual traffic with the vertical inclination on the road was clarified by using the probe car. In addition, the root mean square rate fell by 69% in comparison with the previous estimation method by using the BPR function that considered the vertical inclination on the road, and the accuracy of reproducibility.

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Congestion of the freeway is caused by not only excessive demand for the mainline but also the influence of the exit ramp queue on the mainline. Actually, freeway congestion is largely generated by a mainline spillover of the exit ramp queue. Cause of the difficulties of building new and expanded roads in urban areas, Intelligent Transportation Systems (ITS) are essential to maximize the utilization of existing facilities such as Lane Control System (LCS), Ramp Metering, and Variable Speed Limit (VSL). This study is aimed to study of traffic features of the expressway with exit ramp and develop the integrated model with VSL and exit ramp metering. First we explain the principles of exit ramp metering and VSL based on shockwave theory. Second we suggest integrated control model for the exit ramp using both VSL and exit ramp metering.

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The capacity drop, which is defined as discharge flow drop after bottleneck activation, has been frequently observed in urban freeway, especially in merging sections. Although many previous researches on capacity drop have been studied, still measurement methods for freeway capacity and discharge flow vary case by case according to researchers, and the results cannot be compared each other. In this paper, we first introduced a systematic methodology to estimate roadway capacities and discharge flows from the detector data to find capacity drops. Secondly, we found the relationship on how the number of lanes influences the amount of capacity drop in merging sections in California freeways. The results clearly showed that the capacity drop is strongly related to the number of lanes.

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The purpose of this sutdy is to analyze influence between two parts of no-signal diamond type intersection by microscopic simulation and to validate application of the existing analysis method of no-traffic signal intersection of Korean Highway Capacity Manual.The influence between two intersections was measured by the average length of waiting traffic lines. Based on the traffic volume of the present US traffic signal installation criteria, the simulation was carried out by varying straight-through traffic volume and left-turning traffic volume. As a result of the analysis, at the level of traffic volume of the present traffic signal installation criteria, the influence between two parts of the no-signal diamond type intersection was found to be insignificant. Therefore, it was found that applying the existing analysis method of no-traffic signal intersection of Korean Highway Capacity Manual to each part of the intersection is appropriate

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Current traffic information such as instantaneous journey time estimates are usually provided to road users in advanced traveler information systems. However, it is difficult to validate these instantaneous journey time estimates. This is because instantaneous journey time reflects the traffic condition in terms of current travel time at different road segments at the same instant. No single driver can normally experience the instantaneous journey time except for travelling on a very short section of road under light trafficked condition. In this paper, a survey method is proposed to demonstrate how to validate instantaneous journey time estimates. Observed instantaneous data have been collected by floating car surveys for validation of the instantaneous path journey time estimates provided by the Journey Time Indication System in Hong Kong. The results show that the proposed method can validate the instantaneous path journey time estimates satisfactorily with adequate sample sizes.

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Through traffic using streets in residential areas as alternate routes to bypass congested arterials and other roads impose externalities on the residents. These include emissions, noise and road crashes involving vehicles and pedestrians. As such, there are efforts to try to reduce through traffic in order to reduce its negative impacts. Among such efforts are the formulation and implementation of traffic schemes as well as the use participatory methods. A university campus whose roads are open to general traffic has similar characteristics as a residential area although the nature of land use generates more traffic. Nevertheless, a good environment is desirable and schemes are developed to achieve this. This paper presents the case of a university whose roads are open to general traffic. Traffic schemes are evaluated based on their effectiveness in reducing unwanted traffic. Recommendations are made on how to sustain such schemes and their transferability to other cases.

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Traffic signal control is one of the most cost-effective means of improving urban mobility. With the recent progress in the ITS (Intelligent Transportation System) and the installation of the Real Time Traffic Control System, traffic signal controlling is conducted online and in real time. TOD Signal Control is used with the system, but no definite methodologies have been proposed for efficient TOD Timing Plan. Therefore, methods and processes are needed for optimizing the traffic signal timing plan in order to improve the efficiency of the traffic signal system. This paper study on the optimization of TOD Signal Timing for arterial roads, the application effects of the signal time were assessed in the field. We defined a method to separate TOD breakpoints and optimize TOD intervals for improved traffic signal time. The proposed approach was implemented on ten coordinated signalized intersections, outperformed the previous signal time.

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Computer simulation of traffic is an approach to ease the traffic analyst in foreseeing and analyzing the most likely impacts of a traffic incident. The analysis could be complicated while considering the interaction between vehicles in the traffic stream by means of mathematical models. The result could be graphically presented in three-dimension animation, which will allow communication with less-technical audience such as the communities. And most importantly, the simulation is on computer so that testing with the real traffic is not needed. This practical paper presents an example of employing traffic microsimulation in analyzing the impact of traffic incident on Ratchapruek Road, which is responsible by Department of Rural Roads, Thailand. It has shown that different types of traffic incident cause impact at different level of severity. It depends on many factors such as location of the incident, lane closure, as well as the traffic volume.

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This paper investigates characteristics of the stop-and-go traffic wave that occurs frequently in congested traffic, and describes its development and evolution in time and space. Using NGSIM trajectory dataset, we investigated the relationship between the development of stop-and-go waves and lane changing events which causes deceleration of vehicles and subsequent wave growth and dissipation. Asymmetric traffic theory assuming the separation between acceleration and deceleration behavior was used as a framework for interpretation and explanation of the observed results. And, reciprocal interactions between consecutive stop-and-go waves were studied. Finally, we concluded that the characteristics of stop-and-go waves are closely related to asymmetric driving behavior.

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The signal intersection analysis method in the Korea Highway Capacity Manual is far more complicated than other facility analysis methods and requires a variety of variables, so it has difficulty in situation surveys and analyses compared to other tools such as T7F. Due to this problem, the Korea Highway Capacity Manual is low in use frequency, and actual analysis is performed by inputting only traffic volumes and signal operation types. A total of 32 input parameters by movement is set as a basic condition, and the change amount in delays between the minimum and maximum values of other variables is reviewed to analyze its sensitivity. The effects on the left turn, straight and right turn transportation differ depending on the kind of input variables, so the range of analysis results varies depending on the characteristics of relevant variables.

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In Korea, there are few preemption strategies for an emergency vehicle(EV). Moreover, there is no strategy to apply to real circumstances. Without preemption, EV's drivers have to drive cars depending on only their own judgment. Also it causes danger of other vehicles on the street at the same time. Previous studies tried to overcome it but have progressed with shortage of useful traffic information. Therefore, we set up a preemption strategy based on real-time vehicle information. Especially, this strategy minimizes stops of EV caused by minimum greens for other phases controlling signal earlier. Proposed algorithm result in increasing speed of EV by 17.14-59.32% and increasing delay of total vehicle by 3.62-7.90%. Despite negative effect on total delay, it shows meaningful result which offers a new possibility to give more time for executing preemption strategy by eliminating limitations generated by minimum green time, queue and a way of point detection.

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Providing travel time information is not only basic part of ATIS(Advanced Traveler Information System) but also very important factor for user's route choice. However, although there are various method for collecting travel time data, time-lag have to be came up when data are collected. And it bring about low accuracy of information, especially on peak hour where information providing is more important. In this study, to estimate stochastic amount of time lag, using Markov Chain that show discrete probabilistic transition. Difference Ratio of TCS between actual travel time were used as transition probability of Chain Process. Through this process, gap between actual travel time and provided travel time became reduced. To verify this model, actual travel time data between Seoul IC and Suwon IC was applied into the model. Consequently, predicted data were verified to correspond with actual travel time by comparing with two-tailed t-test at 95% level of significant.

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As improving air safety has always been the ultimate goal for the airline industry, Safety Management System (SMS) gains enormous attention for its systematic concepts and implementation. This qualitative paper reveals the perception gaps in the SMS execution between frontline employees and their immediate supervisors in the airline industry. The most representative crews in the airline industry including cockpit crew, cabin crew and maintenance crew are interviewed. The results advise airlines of the necessity to further redeem the policies, procedures and audit action of the SMS execution based upon the authentic feedback from the frontline employees.

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This study investigates the relationship between accident location and land use patterm in the city of Newcastle upon Tyne, England. This paper distinguishes between males and females of working ages, between weekdays and weekends and between working andleisure time. Data from the the UK Census 2001 showed that most pedestrian journeys to work started and ended in the same ward (an administrative area of approximately 10km2). Accident data were all accidents involving pedestrians of working age during period between 1998 and 2007. Generalised Linear models were developed using the number of pedestrian accidents as response variables and census and land use data as predictors. Sensitivity analysis showed that an increase of 1% in the proportion of retail land use in a ward will, on average,lead to an increase of between 24% and 68% in the number of accidents involving pedestrians of working age.

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The Study on National Road Traffic Safety Master Plan in Vietnam provided various comprehensive countermeasures to ensure the traffic safety until 2010. For the complexity, the full implementation of this Master Plan is predicted with numerous difficulties that not related to resources only but also challenge the determinations of the Government. So, it is necessary to understand regularly the status of implementation, especially bottlenecks and problems hindering implementation. Based on information through various questionnaires and interviews, it evaluated this status and found that about half of measures are at the good or acceptable level of progress. They a belong to one single sector or in concordance with policies of related responsible agencies. Others are mainly that need further consideration and attention of related agencies, especially those with great social impact and/or dealing with institutional, organizational framework.

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Development of a hierarchical tree based regression model (HTBRM) to find the causal factors of traffic crashes at rural sections of the road is presentenced in this paper. CHAID, rarely used type of HTBRM, was used to model traffic crashes in six national roads of Hokkaido, Japan from 1997 to 2001. CHAID is a non binary HTBRM therefore able to represent the complex relationship between the traffic crashes and the dependent variables. Four CHAID models 1 km non-winter, 1 km winter, 3 km non-winter, and 3 km winter were developed. Models with 3 km road segments were found to be better performing. Tunnels, bridges, and snow sheds were found to be significantly increasing the traffic crashes in winter months of the year. Models were able to represent the complex relationship between traffic crashes and the independent variables. Further several combinations of variables which cause high number of traffic crashes were identified.

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Road intersections are accident-prone locations for traffic. To avoid accidents in the vicinity of intersections, vehicles should avoid entering dilemma zone. In this paper, a model formula was compiled that represents vehicle movement at a signalized intersection to gain an understanding how to ensure safety by making an earlier decision before the signal change to yellow. This formula clearly shows that an earlier decision can result in better safety at signalized intersections by preventing entry to the dilemma zone.

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The current training programs for learning to drive a passenger car in Taiwan are mainly private driving schools. The current evaluation method for the teaching quality of private schools is considered unpractical due to its 51 complicated criteria, and inconsistent evaluation goals. Therefore, this study aims to review the current evaluation problems and establish a new evaluation system. The goal of the new evaluation system is to improve the educational quality of the course resulting in more knowledgeable and better drivers. The objectives are administrative quality, course education, technical education, and research and development. There are 9 criteria included in this system. This research applies the Analytical Hierarchical Process questionnaire to determine the relative weights of each objective and criteria. And, this study provides a new operational and practical evaluation model for private driving schools according to a detailed design for the measurement of every practical criterion.

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Sun glare is known to adversely affect driving conditions, and some measures against traffic accidents from sun glare have been implemented. Quantitative analysis of the influence of sun glare on traffic accident occurrence has not been carried out, so the seriousness of such glare as a traffic safety problem is unknown. The Chiba Prefectural Police Headquarters has been recording latitude and longitude of the accident location and vehicle travel direction as additional data items for traffic accidents in the prefecture. We used these additional data items to analyze the degree to which sun glare affects traffic accident occurrence. It was found that when the sun is in a position that tends to blind drivers, traffic accidents tend to be more frequent. The effect of sun glare on accident occurrence was quantified and was found to be very adverse.

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The WHO released a Global Status Report On Road Safety: Time For Action in July 2009. Here we analyse the data reported by Asian countries. The report demonstrates that a few high income countries have unreliable statistics, and on the other hand a few low-income countries are able set up good data collection systems. Therefore, all countries should be able to set up reasonable data reporting systems given the right policies. Overall and road user specific fatality rates do not have a high correlation with country income levels. The reasons for this are not known. In the absence of more reliable data and identification of risk factors for each country, it is not possible to give very specific country based countermeasures for road safety. It would be adequate at present to focus on measures that have international validity and are known not to have negative side-effects.

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This paper explores motorcycle and driver characteristics associated with motorcycle accident involvement. An interview targeting motorcycle drivers was conducted in Phnom Penh. A sequential strategy including clustering and classification tree was adopted. After the groups of motorcyclist with homogeneous driving behavior are identified by cluster analysis, the classification tree was employed to establish the relationship between accident involvement and motorcycle's and driver's characteristics variables for each of the groups. To identify the importance of the variable associated with accident involvement, Random Forest was employed. The key finding here is that the job has the most significant effects on the accident involvement. Other characteristics associated with accident were also identified and discussed. Based on the discussions, several intervention measures were speculated as potential for motorcyclists' safety improvement.

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