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The behavior of lane-changing for buses has an effect on the traffic flow around the bus stations. Despite the growing literature on this subject, very few empirical studies exist on the mathematical models of the influence of buses on the traffic. The purpose of this research is to build a mathematical model of the delay of traffic flow induced by buses entering and exiting the bus bay. A bus bay in Beijing, China is taken as an object. First, the headway distribution is analyzed. Second, the process of buses entering and exiting the bus bay is discussed and a delay model is formulated combining the relevant theories of probability theory and calculus knowledge. Finally, the model is verified by conducting an error analysis. The study provides a theoretical basis for estimating the delay of the traffic flow.

Mixed-traffic streams that contain motorized vehicles (m-vehicles) and non-motorized vehicles (nm-vehicles) are very common in urban areas, especially in the branch without physical isolation of m-vehicles and nm-vehicles. To study the impact of m-vehicles on nm-vehicles, a comparison study between driving m-vehicles with and without nm-vehicles on their right sides was conducted. Data was collected by video recorder at one cross section of a road. Mixed-traffic analysis has focused mainly on the flow rate, variation of speed, acceleration, and headway as indicators to reveal driving behavior. In particular, this paper discusses the nm-vehicles’ impact on the m-vehicles’ trajectory when the m-vehicles and nm-vehicles are on the same cross section of road. Statistical results show that the lateral position of m-vehicle is related to the lateral position of nm-vehicle on its right side, especially, when the nm-vehicles is close to the m-lane. The potential hazard of nm-vehicle’s behavior was also determined.

The determination of capacity and delay significantly affects the transit system’s performance from the perspectives of operators, passengers, and vehicles. Buses will form the spillback queue, in the entrance of the bus bay, when the demand of buses stopping is high. Therefore, bus bay blockage will reduce the capacity and service level of the bus bay and increase the dwell time. The upper partial moment is used to estimate the maximum threshold of blockage probability. The capacity of the bus bay is modeled as a function of arrival buses, blockage probability and critical headway, taking into account spillback and blockage in bus bay entrance and exit. According to bus bay operating time and dwell time, the research aims at estimating a delay based on blockage probability, traffic flow of the adjacent lane and the number of berths. Congestion can be effectively alleviated by increasing the number of berth when demand of buses stopping is low due to the probability threshold has significant change. However, the probability has little significant change when traffic flow of the adjacent lane is more than 450veh/h. It is significant to have congestion delay when multiple bus routes converge into a bus bay.

Car-following is the most frequent driving scenario, and is characterized by headway. Headway is a measure of the temporal space between two vehicles. It relates to the time available for a driver to react, and is a safety measure of car-following behavior. The characteristics of car-following headways remain poorly understood in China and this has a secondary effect on road alignment design, road capacity, traffic flow stability, traffic safety, and the design of many in-vehicle systems. With high validity naturalistic driving data, this study investigated the distribution of drivers’ car-following headways and how drivers would adjust their headways due to level of operating speed, visibility, roadway type, and traffic density. From 60,689 km of naturalistic driving data, 1,489 car-following events were identified. Headways were then extracted and statistically compared across different driving situations to quantify changes in car-following headways as a result of driving situations. The results of this study show that (1) the distribution of car-following headway was similar to a lognormal distribution; (2) drivers tended to maintain longer headways in slow-speed driving, nighttime, surface roads, and dense traffic conditions. The results of this study may be valuable for understanding car-following behavior and traffic simulation.

This paper examines the impact of different exit designs on the collective movement patterns of the crowd. A series of controlled experiments with 50 participants were performed in a designed chamber. Considering different exit locations (exit at the middle/corner) and obstacle placements (without/with obstacle) under two desired speed categories (normal walking/slow running), eight sets of experiments were conducted with three repetitions. From the trajectory data derived from the recorded video footage, crowd egress features such as escape headway frequency distribution, escape time duration, and relative effectiveness were obtained. Results showed that for corner exits, without obstacle was the most effective scenario. In addition, presence of obstacle increases the egress time, compared to middle exits. Findings of this study are useful resources for crowd researchers to validate their proposed crowd simulation models and for architects to improve exit designs.

The roundabout’s capacity is usually analyzed by the gap acceptance theory model. There are obvious differences between the value calculated by the model and the observed values. This study modifies the model with a parameter reflecting the change of the critical headway analyzed by multiple linear regressions, and validates the model with the data from VISSIM simulation. Compared with the classical model, the relative error of the modified model reduced by 50 percent.

Taking the advantage of convenience and high efficiency, the subway system has been a favorite of passengers. Providing better services to minimize the travel time for the passengers is of particular importance. Metro train’s headway and running time have determined that the most important factor affecting the travel time is the passengers’ walking time. In order to study the relationship between those factors, a field study was conducted on Line 1 of Beijing subway system. The investigated facilities include the passageway, platform, escalators, and stairs. For each walking facility, a function of travel time and distance was calculated and the factors that affected the walking time were analyzed.

Emergency evacuation plans for metropolitan areas frequently rely on transportation simulation models to predict evacuation durations. Previous work frequently assumes drivers will demonstrate similar aggressiveness during an evacuation as during peak hour commuting. On the contrary, several studies suggest driving behavior is different during evacuations. The objective of this study was to find if changing driver aggressiveness will significantly impact the expected duration of a no-notice evacuation. In this study, the authors used microscopic traffic simulation software to model travel demand for a no-notice evacuation scenario in the St. Louis metropolitan area and represented driver aggressiveness by adjusting headway, following distance, and other parameters. This model included the traffic volumes predicted by the regional planning agency and the route diversions and freeway service patrol operations expected by the local state Department of Transportation. Although the findings suggested that changes in driver aggressiveness will not significantly change the evacuation duration; for key evacuation routes, a significant reduction in travel time and delay was found when driver aggressiveness decreased, compared to the observed normal peak hour driver behavior. These findings suggest that traffic engineers and emergency managers should carefully consider the wording of evacuation information provided to drivers in an attempt to reduce anxiety and prevent aggressive driving during a no-notice evacuation. Further, research should attempt to capture driver behavior during future evacuations so modelers can model travel behavior more accurately.

Accurate data on passenger activity and traffic patterns at airports are essential information for people flow analysis and management, space use, service monitoring, security enhancement, productivity assessment, and resource optimization to improve or maintain the operating means at airport facilities. bCounted is the automatic people counting and people flow management system to provide this information. The system offers sophisticated solutions for automatic people counting (APC) on trains, automated people movers (APM), buses and shuttles as well as at stations, security-sensitive areas, and any location where people move through portals. Customers include airport authorities, bus and shuttle operators, door and portal manufacturers, OEMs, retailers, and providers of services where frequency and people flow management play a role. bCounted features infrared APC sensors which make use of the latest “time-of-flight (TOF)” technology. Inconspicuously mounted above the door or portal, the sensors provide in real-time three-dimensional (3D) images of the field of vision and the people or objects to count. Working like an infrared camera, the sensors distinguish between passengers and objects, e.g., wheelchairs or luggage carts. A communication module captures the APC data, correlates it with location and time, and communicates the count data to a cloud-hosted backend. In mobile applications, e.g., on APM vehicles or shuttle buses, wireless GPS modems are used to track the vehicles. The backend produces customized “as needed” reports and can be accessed anywhere in the world via a Web Portal. Since 2007, bCounted has successfully been utilized in APM and shuttle bus systems. bCounted provides an effective method to generate information and statistics about ground transportation and facility usage, accurate counts at stations, exact passenger frequency reports for vehicle capacity and headway planning, statistics for fund application, and to assign operation cost to different system partners. It notifies transportation operators and airport facility staff if and when to take pre-determined, ad-hoc measurements or corrective actions based upon passenger frequency or people flow.

Automated transit systems, especially fully automated metro lines, have been in operation for more than 30 years. Most of these automated systems have revealed a great success story in terms of ridership, safety, and reliability, but also in terms of operating costs. The efficiency of such automated transit systems is significantly higher than for conventional rail systems, which is the primary reason for this operational and monetary success. However, this higher efficiency depends very much on the way the operation of the system is organized. A flexible and demand-driven train headway, such as for the VAL in Lille, France or the Skytrain in Vancouver, Canada, provides a very frequent train service attracting a high ridership on one end and requires less operational expenses (effort) to provide the train service on the other end. A very meaningful benchmark indicator of this efficiency has been found with the overall ‘traffic efficiency’ which is defined as the ratio of the total passenger kilometers travelled per year and the produced seat kilometers per year. Empiric studies show this efficiency to be less than 20% for conventional (driver-operated) urban rail systems and approximately 35% for automated transit systems. Hence, automated train operations in combination with flexible and demand-driven train service can double the total efficiency of the rail system. Complementary to such empiric observations, an analytic model has been developed to explain the efficiency increase in a very straight-forward way. The proposed ‘traffic efficiency’ indicator can be used to benchmark different systems or even different lines of an operator the reveal areas of improvement within a network. Very quick and straight-forward calculations are possible to estimate the expected efficiency increase when converting conventional operation into fully-automatic operation. Quick feasibility checks can indicate whether such an automatic and demand-driven operation is beneficial at all. The paper shall present the fundamental differences in terms of efficiency found between conventional and automated rail systems, explain the proposed efficiency indicator including the mathematical background. Practical implications are discussed for making decisions whether to migrate to automatic operation and what conditions are most favorable.

Recently, with the development of urban road net and the shortage of land resources, underground expressway has a rapid development, but the associated research of traffic safety is lagging. The traffic flow data and method of mathematical statistics is used to analyze the difference of vehicles running index such as speed, space headway and lateral movement in underground expressway comparing to such things in expressway above the ground. It also indicates the possible impact on the safe operation of the underground expressway caused by these differences, and gives some suggestions on the improvement of the underground highway safety from the point of safety of vehicle operation.

Recently, as the rapid development of electronic information and wireless communication technologies, Communication and information shared between the vehicles become possible. In the case of vehicle communication, driver can know the information of vehicle in front of it, so the reaction time will be different with tradition. The vehicle information of this paper includes headway, acceleration and speed. Firstly, the experiment without vehicle information on driving simulator was done to verify the driving simulator. Then, the experiment with vehicle information on driving simulator was done and the data was analyzed. Finally, the results show that the reaction time with vehicle information obviously less than without vehicle information. The difference of reaction time caused by age increases, however the difference of reaction time caused by gender decreases.

The headway distribution is a vital foundation for the work of traffic control，capacity calculation，traffic safety analysis, etc．In this paper, based on the analysis of data collected in Shanghai, the statistical features of headway distribution of different road section at the same volume are investigated at weaving section of signalized intersection upstream. The method of χ2−test is adopted to analyze the time headway distribution. The results indicate that in the normal period, headway distributions of three typical sections of the fast lane are fitted well with the negative exponential distribution, and the average headway of the stop line section is the minimum, and the average headway of the weaving section is the maximum. This investigation provides a useful basis for further research on capacity of weaving section of signalized intersection upstream, signalized intersection upstream planning and management.

Based on the analysis of drivers’ gap acceptance process of roundabout, the video was used to record drivers’ choice behavior when the vehicle entered roundabouts. Through the statistics and analysis of survey data, the results indicated that the gap acceptance behavior can be described by binary choice model—model. The calculation method of critical time headway was given which related with space headway and speed of the rear vehicle on major road. A conclusion was derived that the critical space headway would increase when the vehicles’ speed on the major road increased from the calculation results by use of SPSS software.

This paper analyzes the interaction process of the running trains associated with the minimal headway for high-speed railway in a more reasonable and sophisticated way after systemically investigating previous researches. A set of new formulas are proposed to improve the calculation accuracy of minimal headway. In the case study section, the proposed methods are tested to calculate the minimal headway of the running trains of different speeds range from 250 km/h to 350 km/h with the calculation step of 10 km/h. The case study results show that with the increase of the maximal allowed speed, the headway between two trains running in one section, the headway between two arrival trains and the minimal headway of the high-speed railway increase, while the headway between two departing trains is a constant. The main conclusions can be drawn from the case study results: (1) Headway between two arrival trains is always the bottle neck to narrow down minimal headway of high-speed railway no matter how the maximal allowed speed of the train changes from 250 km/h to 350 km/h. (2) The minimal headway of high-speed railway is always greater than 180 s with the maximal allowed speed of the train ranges from 250 km/h to 350 km/h, which means that some improvement measures should be taken to accomplish the goal of reducing minimal headway to 3 min. (3) The improvement of braking performance of the train can reduce the minimal headway of high-speed railway.

With the flow rate increases, two or more vehicles would form platoons at freeway on-ramp bottlenecks. Based on vehicle trajectory data from I-405 and I-95 freeways in the US, this study focuses on empirical analysis of platoon characteristics from free flow to congestion flow at on-ramp bottlenecks. The platoon basic features (e.g. platoon size, platoon speed, platoon time/space headway) on freeway mainline are analyzed. Then, the platoon merging behavior at on-ramps is investigated. It is found that (1) platoon size distribution follows monotonic decreasing function; (2) Platoon time headway fits both normal distribution and lognormal distribution, and non-platoon time headway fits shifted negative exponential distribution; (3) The platoon is not necessarily moving bottleneck considering the speed difference between platoon and non-platoon vehicles under free flow condition; (4) Merging by a platoon is more invasive than that of single vehicles, and would be more disruptive as platoon size increases.

Ramp merging sections are regarded as the most common segment of recurrent congestion occurred on expressway as two separate traffic streams join to merge a single stream or lane. To address this issue, the first step is to identify the merging mechanism of vehicles on-ramp is method of alternate passing model. Then a new concept of merging headway and the survey method of the actual merging headway is introduced in this study. Based on the theory of saturation flow rate, merging headway model is proposed to estimate the capacity of the right-most lane. In order to validate the rationality of merging headway model, the Greenshields model, Drake model and Underwood model are applied in this thesis. At last, reduction factor model of the saturation flow rate on the right-most lane under the condition of various factors is put forward, which is mainly based on the geometric factors. The findings from this research demonstrate that the capacity of curb lane at merging section is determined by the ramp merging angle and the length of acceleration lane.

Block mode of a transit corridor is a key characteristic and plays a decisive role in train delay adjustment. This paper focuses on how train delay and propagation is affected by different block modes and how to adjust train delay and propagation of three types of block mode. On the condition of minimum headway, this work tackles the problem of rate of curves of train delay spread on subsequent continuous trains. In addition, a variety of influence factors are summarized, including braking mode, length of block section, and real-time detection of train position. The relationships between these influence factors and train delay adjustment are also revealed. Finally, measures to reduce delay (including initial delay and additional delay) are presented.

Lots of research has been carried out to study lost time and departure headway of certain phase duration in urban intersections, due to its importance to signal timing. Most previous research focused on the situation of static queuing vehicles or constant vehicle arrival rate. However, the departure process is much more complex than an ideal scenario. In this paper, the authors propose a distribution model for effective flow rate at signalized intersections, including both the saturated situation and unsaturated situation. Finally, the Monte-Carlo simulation shows that the model is simple and efficient in different situations.

Through numerous field observations at 5 signalized intersections in the center of Shanghai City, this paper studied the reliability of signalized intersection capacity. The volatility of the intersections’ headway was described firstly. And then, 1500 signal circles data of the saturation headway of left-turn lane at 5 intersections were collected by camera, and some descriptive statistics parameters of the saturation headway were investigated. Since the multiplicative inverse of saturation headway is the saturation flow rate, so the saturation flow rate data can be easily got. The authors found that the capacity of signalized intersection capacity yielded to normal distribution and it could be explained by a famous low of the probability theory. Then an analogy was made between the reliability of structural capacity and signalized intersection capacity, the reliability function of signalized intersection capacity was defined. Thus, the capacity and its reliability can be understood from a viewpoint of probability. The research develops detailed models to describe the signalized intersection capacity and proposed a better understanding.

The Highway Capacity Manual 2000 (HCM 2000) model estimates entry capacity of roundabouts under an assumption of headway (time gaps) following an exponential distribution. Entry capacity is thus calculated by circulating flow, critical gap and follow-up time. This paper aims to analyse: (1) the actual distribution type of headway; and (2) the relative error resulting from the assumption. To this end, a simulation that simulates the real traffic operation is conducted based on survey data from an existing roundabout in Queensland, Australia. A comparative study is then carried out to compare the results from the HCM 2000 model and the simulation. It indicated that the HCM 2000 model is not appropriate to be established under an exponential distribution. Although HCM 2000 model over-estimated capacity in our case study, it is still an acceptable approximation. Results suggest that the relative error is 6% under the circulating flow of 468 vehicles/hour.

For an integrated public transport system, metro feeder buses become a key commuter transport mode connecting the suburban residential center and main transit lines in many Chinese mega cities. As the feeder bus is usually operated at a lower frequency relative to the metro, the transfer impedance may be restrained. This study attempted to design a timetable for a metro feeder bus route. Two timetable designs -- static and dynamic -- are proposed. In the static timetable design, it is assumed that the metro train service is frequent and maintains an even headway, while the feeder bus service is infrequent and the bus headway is an integer multiple of the metro train headway. The bus headway is determined based on the fleet size (and or bus round trip time) constraint. Furthermore, considering that metro and bus arrival times are deterministic, the offset between metro train arrival and bus departure times is set to be equal to transfer walk time. The dynamic design approach considers the static timetable and further improves on it to minimize transfer wait time based on average weekly train specific transfer volume data. The dynamic design problem is solved by the proposed algorithm which can transform multi-variable, unconstrained optimization into a sequence of single variable search.

The coordinated operations of urban rail and bus systems are an important part of an integrated mass transit system. This paper takes the transfer system, consisting of rail and bus, as the research object. The costs of the system, including enterprise cost and passenger cost, are analyzed. Taking headway as the optimization variable, the authors analyze its impact on passengers and the relationship between it and system cost. Considering transportation efficiency, a schedule coordination model between urban rail and bus is established. Its aim is to minimize the total cost (consisting of enterprise cost and passenger cost) and maximize transportation efficiency by optimizing transit schedule parameters. At the same time, a solution is proposed to the optimal model. The validity of the model is verified by an empirical analysis. The result shows that the implementation of schedule coordination can increase the enterprise operation efficiency and benefit of passengers.

An expressway's merge area, which is the main cause of freeway traffic accidents, is located in the interchange of the mainline and the ramp. In order to study the traffic capacity of an expressway's merge area, this paper makes reference to related research results of scholars at home and abroad. Based on these results, this paper establishes a connection with the double Gamma probability density function (Double GamPDF) and the headway of the outside lane. In this way, it can achieve a probability curve. Using the measured data, this study verifies that the fitting effect can conclude that the curve is strongly fitting. Double GamPDF is introduced to integral and the model of the merging area's import volume can be determined by using the integration method. The data on the number of vehicles and the headway (both in the main lane and on a ramp) in the Xi'an ring expressway are obtained through the survey. The survey data is used to compute the maximum import volume. Compared with the measured import volume, the calculation result can be proved to be reliable and have high suitability.

The purpose of this study is to improve the bus passenger flow distribution model to more accurately reflect the real world situation. From July 2008 to June 2013, in each season, during peak period and hollow, passenger waiting time was surveyed in Changchun Jinhua and Lanzhou. Six cities, with the number of bus routes ranging from 14 to 153, were included in this study. Experimental data was analyzed applying the wavelet theory and mathematical statistics. In other case studies, the distributing pattern of passengers' waiting time and the limit time of passengers for waiting was researched. These times are interrelated with the actual headway mainly, and are also influenced by the waiting environment and peak period. The conclusion seeks to improve the precision of the bus passenger flow distribution model.

Over the years, the understanding of capacity is the maximum number of vehicles through a road section in a unit of time for vehicles in free organization in certain road and environmental conditions. However, when vehicles in free organization are at signalized intersections, vehicles that are transferring can cause delay. Other parameters, such as vehicle headway and speed, fall far below the desired level to allow actual efficiency and cause a much lower level than the ideal, such that the potential intersection capacity is not fully realized. By controlling vehicles through intersections by some intelligent means, shrinking the headway, and increasing speed under the premise of ensuring safety, intersection capacity and traffic efficiency can be enhanced. Through modeling analysis, this paper discusses a control strategy that can significantly reduce average lane delay by more than 20%, greatly enhancing the ideal saturation flow of the intersections by more than 8 times.

As different drivers have different driving psychologies when driving on the same road, the headway distance kept by different drivers would not be the same and the capacity of this road would be influenced. This paper is developed to analyze the road capacity with the influence of driving psychology. Another capacity model was found which considered driving psychology and safety headway distance based on the method of probability. In this paper, the safety headway distance between two relative vehicles was classified into two categories — absolute safety headway distance (AD) and relative safety headway distance (RD). These two safety distances were used as the headway distance at capacity of the "safe" psychology and the "adventure" psychology, respectively. By analyzing the reaction process of drivers and the vehicles' operation characteristics when braking, a driving psychological parameter was introduced to establish the headway distance model (which considered the influence of driving psychology) and the road capacity model when the influence of driving psychology and safety distance was proposed. Then, the simulation of this capacity model was presented when different psychological conditions were present. Research results indicate that the road capacity relates not only to drivers' reaction time, operation velocity, vehicle length and brake characteristics, but also to the drivers' safety psychology parameter and the proportion of each psychological category of drivers.

The U.S. National Highway Traffic Safety Administration has reported that the major cause of vehicle crashes in the United States has been driver inattention and distraction. Among various types of distraction, cell-phone dialing and text messaging have been shown to significantly degrade driving performance. Existing studies have mainly focused on driver distraction scenarios with one or a few vehicles, and have generally not looked at large-scale simulation of many vehicles. In contrast, currently available software for simulating traffic with many vehicles (e.g., CORSIM and VISSIM) has generally not considered the effects of driver distraction on driver/vehicle behavior. To overcome these limitations, the authors propose a computational modeling framework that integrates a cognitive model of distraction (i.e., Distract-R) and an agent-based traffic (micro-) simulation model (i.e., VISSIM). The framework aims to enable transportation modelers to easily set up virtual experiments and evaluate the impact of distracted drivers on large-scale networks. The authors validate the framework using two existing experimental data sets. Preliminary results indicate that the framework can account for statistically significant changes in speed fluctuation and headway distance in the presence of a significant number of distracted drivers.

This study investigated drivers' braking responses using a simulated car-following task under different initial headways and different lead vehicle decelerations. Study participants drove a high-fidelity driving simulator with an eight-degree-of-freedom motion system. The experiment used a four-factor mixed experimental design, with headway and lead vehicle decelerations being the within group factors and age and driving experience being the between group factors. A total of 30 drivers were given the opportunity to avoid a collision by braking/steering when a lead vehicle slowed at initial headway distances of 1.5 sec and 2.5 sec and at decelerations of 0.3 g, 0.5 g, and 0.75 g. ANOVA with repeated measures was used to compare the drivers' perception response time across the different conditions. Results showed that a) drivers' perception response time was less under lower initial headway and larger LV deceleration conditions. The propensity to use a braking or braking and a steering maneuver to avoid the collision was also examined.

Aiming at improving the service reliability and running stability, great numbers of control strategies were proposed. Different control strategies only under appropriate running state can play well. So different bus vehicles running state were defined, which is stable state, closing state and departing state, basing on the analysis of bus transit running process. From the historical bus trajectories, it was found that the headway bias amplified as buses travel on the route. Then put a recognition of running state method forward by using the relative Mean Absolute Error (MAE) of historical based travel time estimate model and tendency based travel time estimate model. At last the optimal boundary value for different running state was calibrated. This method can also be can be applied for different bus lines.

The braking process is composed of drivers' brake reaction and drivers' deceleration after braking. In order to understand driver's collision avoidance behavior, it is important to understand how drivers maneuver after braking. Experiments were conducted on the Tongji University Driving Simulator to analyze the behavior of drivers after braking with different lead vehicle's (LV) decelerations (0.3g, 0.5g, 0.75g) and different initial headways (1.5s, 2.5s). Among the 140 cases where drivers avoided collisions only through braking, difference of drivers' collision avoidance behavior were compared by brake pedal rate, time to 25% brake, time to 50% brake, and time to maximum brake. Results indicated that a) brake pedal rate was faster under higher level of risk; b) experienced drivers tended to have higher brake pedal rate compared with the novice drivers; and c)compared with the change in LV's deceleration, driver was more sensitive to the change in braking headway.

The minimum headway of trains is an important technical standard in railway survey and design. Common passenger trains on high-speed railway have great influence on the headway of trains. This paper mainly analyzes the type of coach, passenger train composition, and train operation control system. The calculating model of headway of an electric multiple unit (EMU) and common passenger train was put forward in this paper. According to the calculating model, based on the train control system level 2 (CTCS-2) for China and the train running monitor and record device (LKJ) and the ground signals, taking the YunCheng northern station of Datong-Xi'an high-speed railway as example, the arrival-pass and arrival-arrival headway of common passenger trains and EMU and the pass-departure headway of EMU and common passenger train can realize 3 minutes. And the departure-departure headway of EMU and common passenger trains can realize 5 minutes. And some valuable research results will be provided for survey and design of special lines for passenger traffic.

Dhaka is one of the most densely populated cities in the world. The abrupt increase in population along with diverse urban land use patterns has engendered an ample travel demand. In addition, gradual deterioration of level of service of the public transport system and increasing private car ownership create acute intolerable congestion. In these circumstances, Bus Rapid Transit (BRT) is one of the most effective short-term solutions because of its high capacity as well as relatively low construction and operating cost. Despite the high opportunities of introducing BRT in Dhaka, it will face some operational difficulties such as high occupancy, high operational fleet size, small headway, priority in intersection and signal control, etc. Results show that to satisfy the projected high passenger demand, the headway will be 16 seconds and operational fleet size and vehicle occupancy will be very high in many locations, which will make the BRT operation difficult and ineffective.

Electronic toll collection (ETC) is an important part of the intelligent transport system (ITS). This paper first introduces the meaning of ETC, then discusses the composition and the workflow, and finally analyzes advantages and disadvantages. Saturated headway is calculated by a mathematical model formula to get the capacity of an ETC lane. And through vissim simulation technology, the author gets the station capacity about different ETC lanes. Finally the author describes all of the level of service and provide a reference for setting the ETC lane.

Drivers may be influenced by some factors, such as the front vehicle’s velocity, and headway. But the influences of vehicle honk on traffic flow and driver behavior have seldom been investigated. The present study took this issue into account by proposing a new symmetric two-lane cellular automaton model. It is based on the symmetric two-lane cellular automata (STCA) model that was proposed by Chowdhury. The lane-changing rules of STCA were revised, and some other rules were added that took the honk effect into account. This study also focused on the relationship between drivers’ characteristic and honk actions. The results showed that different kinds of drivers made different decisions when their front vehicle hindered him. Based on the observation, the added cellular automaton rules included not only the honk rules but also the driver’s characteristics. Finally, some simulations were made. The results showed that the honk action enhanced the flux in the intermediate-density range. Besides, the relation between the percentage of three type of driver and traffic flux was considered. The results figured out that the rash driver’s honk increased the lane changing times, which only resulted in the fluctuation of traffic flows. So with the increasing of rash driver’s percentage, the traffic flow flux did not increase in the high-density range. As far as the percentage of cautious driver, the traffic flow had less fluctuation than the former results. In summary, it can be argued that the honk behavior is not encouraged in the asymmetric two-lane model.

With the increase of urban congestion，scholars at home and abroad pay more attention to roundabouts in recent years, which are important nodes in the urban traffic network. A large number of research about roundabouts have been made such as capacity, security, etc. And headway, an important traffic flow parameter, is also studied by some researchers. However, due to the constraints in geometric condition of roundabout and acquisition equipment, it is difficult to obtain the continuous headway data in distinct locations. Using VISSIM, A single-lane roundabout is built in this paper. Considering the geometric characteristics of the roundabout, some basic parameters of driver behavior in the simulation software are calibrated. Simulation experiments under different traffic conditions at four collection points near an approach are made, the results are as follows: The distributions are described in different locations and traffic conditions, and the PDF distribution are given visually with the help of kernel density estimation method, which shows that it has a distinct headway distribution characteristic with the difference of traffic volumes and collection locations. Then the average time headway values are analyzed, which indicate a decreasing trend with the increase of traffic flow. And a fitting analysis is made between AHV and traffic volumes, and the results show that it meets a quadratic nonlinear relationship, while R 2 and RMSE prove that it has a good fitting effect. This paper proves the practicality of VISSIM in roundabout study, and also discusses the relationship between traffic volume and headway, which provides a beneficial trial for roundabout research.

Calculating the passenger-carrying capacity of transportation systems is an important and necessary process to determine if a proposed system can be expected to meet design requirements related to passenger demand. The analysis and calculation must consider many factors that influence the final passenger-carrying capacity of a transportation system, such as safe separation distance, operational headway, average speed of the vehicles, the vehicle control system design, track alignments, ride comfort criteria, dwell time, and system operating modes. While this paper discusses systems with off-line stations and pinched loop systems with in-line stations, the methodologies discussed are applicable when analyzing the capacity of different transportation technologies and networks.

The scientific determination of bus headway is very important for bus transit in rural areas. The problem of setting bus headway on a transit network under deterministic conditions with time varying demand for service and operation cost is formulated as a mathematical programming problem. This paper first proposes a bus headway problem by taking into account the operators' profit and passengers' cost. It proceeds to develop a multi-objective optimization model for the proposed problem, which aims to minimize the social cost in terms of waiting time, inconvenience due to crowding in the bus, and operation cost. The genetic algorithm is subsequently designed to solve this optimization model. Finally, a numerical example based on a real route in Wujin city of China is carried out to demonstrate the strength of this optimization model. The results show that the model and the algorithm are feasible and effective.

Roundabouts have been used successfully throughout the world and are being used increasingly in China in recent years. The primary objective of this study is to identify if the current Highway Capacity Manual (HCM) capacity estimation method can be used to estimate capacity of modern roundabouts in China. To achieve this objective, data was collected from one modern roundabout in Nanjing area in China. Based on the field measured data, the authors estimated the critical headway and follow-up headway using the Siegloch method. With the estimated critical headway and follow-up headway, the HCM model was used to estimate capacity of the selected roundabout. A linear regression model was also developed based on the field data. The models were tested against the capacity measured in the field. Capacity estimation results of the HCM model and the linear regression model were compared. Model validation results showed that the calibrated HCM model yielded a MAPE of 15.7% while the regression model yielded a MAPE of 11.6%. The results suggest that the HCM model provides reasonable capacity estimates for roundabouts in China after crucial parameters are calibrated.

Based on the survey data of three signalized intersections with exclusive triple left-turn lane and with outside trap lane in Beijing, traffic flow characteristics of left-turns are studied by using statistical methods. It shows that the discharge headway and saturation flow rate of exclusive triple left-turn lane with outside trap lane divides into two stages when the discharge time of vehicles in the left-turn bay is less than the left-turn green time. This problem is uncharted in the Highway Capacity Manual (HCM). This research analyzes the effects of relationship between the length of left-turn bay and green time on the left-turn capacity. A theoretic model for left-turn capacity is developed by considering this characteristic. The developed capacity model will be validated on the basis of VISSIM simulations of a real-world signalized intersection. And the results demonstrate that the proposed capacity models well estimate the left-turn capacity at signalized intersections in the case, which the length of left-turn bay and green time is not well optimized and well reflect the capacity loss due to the transitional area bottleneck.

Generally speaking, traffic headway comprises distance headway and time headway, which varies according to velocity and acceleration. Distance headway is a part of the traffic following model as an expression of the stimulus-response factor. A more responsive driver accelerates and decelerates more frequently in response to the vehicle in front, thereby reducing the capacity of the traffic lane. This study attempts to calculate the distance headway in both the Macro Traffic Model and the Micro Traffic Model, and thus determine a steady state for the distance headway. The research results show that the Macro Traffic Model reaches Steady State at 20-23 seconds and the Micro Traffic Model reaches Steady State at 19-23 seconds. This research can be applied to traffic planning, calculation of crossroad traffic saturation rates, or in traffic simulation applications.