Comparative Analysis of Intersection Performance Using PCU Values from NRS and Indo HCM: A Case Study of New Baneshwor Intersection

Although rain and other precipitation is common, analyses of signalized intersections based on the Highway Capacity Manual require clear weather and dry pavement conditions. Three factors may be affected by wet weather: saturation flow, effective green time, and progression. Saturation headway may lengthen, effective green may shrink, and progression may worsen in wet conditions. As a result, signalized intersection operations become less efficient. This is demonstrated in the longer delays estimated for five sample intersections. A methodology was developed for the derivation of the probability of rainfall (Pwet) during the morning and evening peak hours for any intersection in the United States using readily available rainfall accumulation data from the National Oceanic and Atmospheric Administration. Once delay and level of service (LOS) are estimated for both dry and wet conditions, a weighted average is employed for estimating delays and LOS that represent the prevailing dry and wet peak period conditions at a signalized intersection.

Base saturation flow is a critical constraint used for evaluating the capacity of signalized intersections. The Indonesian Highway Capacity Manual (IHCM, 2023) is frequently used for signalized intersection planning in Indonesia. In heterogeneous traffic environments, the driver characteristics and behaviors exhibit significant variations. However, the base saturation flow was also influenced by traffic volume during the observation period. This study modeled the base saturation flow by analyzing differences in morning and afternoon peak hour data. The objective was to examine the base saturation flow at pretimed signal in Banda Aceh, with a focus on traffic volume fluctuations during peak hours. Four intersections were investigated in this study. Unmanned aerial vehicles were employed to record discharge flow pattern within targeted signalized intersection. Manual timing was conducted using stopwatches and geometric road data were collected through direct field measurements. Bayesian linear regression with a Gibbs sampling approach was utilized to recalibrate the saturation flow rate coefficients. The base saturation flow during the morning peak is 284 We, while in the afternoon peak, it is 285 We, with We representing the effective intersection approach.

In response to urban rail transit capacity shortage, a capacity adaption optimization model for the new mixed train operation mode is proposed in the supernormal operation of urban rail transit networks. First, the characteristics of express-local train and long-short route slow train are analyzed to obtain the main influencing factors of capacity adaption. Moreover, various train types are simultaneously classified and recombined in the adaption train operation mode to maximize transportation capacity for passengers. A nonlinear mixed-integer programming model is established to maximize the total number of trains, improving train load rate and reducing the total passenger travel time. In addition, the actual case of Beijing Metro Line 1 is solved to demonstrate the feasibility and effectiveness of the proposed model. The optimal passenger travel time-saving rates of the morning and evening peak hours are 12.1% and 11.5%, respectively. The optimal utilization rates of capacity in the morning and evening peak hours are 79.5% and 84.5%, respectively. Meanwhile, the optimal load factor within the range of 0.7–0.9 would benefit the utilization of train resources and the passengers’ service level. The optimized results show that the proposed capacity adaption optimization model benefits for high service level and practical significance and rationality for operators.

In this paper, we take the example of Changchun City automobile trade logistics park. Based on the design parameters of the project plan given by the design department, we forecast the occurrence quantity of daily peak hours of induced travel in the different functional areas of the building project, attractive quantity of working day morning peak hours, occurrence quantity of rest day evening peak hours, and attractive quantity of rest day evening peak hours, considering the construction area of different functional areas, per unit area residents travel rate, peak hours to increase the number of trips, and other factors. Through analysis and calculation, induced traffic demand can be obtained in the peak hours of building projects. The early peak in the n years is 13,440 (person-time/h). The evening peak in the n year is 13,357 (person-time/h). The early peak in the n+5 year is 15,380 (person-time/h). The evening peak in the n +5 year is 15,472 (person-time/h). The traffic volume in the n year early peak is 2766 (veh/h). The traffic volume in the n year evening peak is 2853 (veh/h). The traffic volume in the n+5 year early peak is 3685 (veh/h). In this paper, the prediction of induced traffic volume of Changchun Kuancheng automobile trade logistics park can provide database for traffic planning and design. It also can effectively avoid the emergence of traffic congestion so as to meet the needs of road traffic in the coming years.

Saturation flow under mixed traffic conditions is affected by vehicular mix and its characteristics, approach grade, driver behaviour, roadway geometry, and road side frictions in the vicinity of intersection. Side friction arises from pedestrian movement, activities of public transport vehicles, and parking of vehicles on road premises. Due to the influence of these factors, realistic estimation of saturation flow is a complex task under heterogeneous traffic conditions. Road side friction arising from stopping of public transport adjacent to signalised intersection tends to interfere with vehicular discharge at intersections. This paper attempts to analyse the impact of far side (down stream side) and near side (upstream side) bus stops on saturation flow rate. As a first step towards quantifying the effect of bus stops, saturation flow of approaches that satisfies the base conditions set for the study were estimated in PCU/hr using area occupancy concept. Mathematical model for the prediction of base saturation flow was proposed. Effect of bus stops on saturation flow rate was then determined by analysing saturation flow rates of approaches where bus stops are located adjacent to intersections. Adjustment factors were introduced to incorporate the effect of far side bus stop (Ffb) and near side bus stop (Fnb) on saturation flow rate. Linear regression models were developed for the prediction of adjustment factors based on data generated using a micro simulation programme. The results of the study showed that adjustment factors vary with distance of bus stop from stop line, width of approach and proportion of green time blocked. The study also revealed that the reduction in saturation flow rate is more when bus stops are located in the upstream side (near side bus stop).

Examining the clustering characteristics and fluctuations within urban areas during peak hours through the lens of bike-sharing is of utmost importance in the optimization of bike-sharing systems and urban transportation planning. This investigation adopts the principles of urban spatial interaction network construction and employs streets as the fundamental units of analysis to model bike-sharing activities during morning and evening peak hours within Beijing’s six central districts. Subsequent to this, a comprehensive analysis of the network’s structural attributes was carried out. A Walktrap method, rooted in modularity analysis, was introduced to discern and scrutinize the clustering patterns and characteristics of communities within the network across different temporal intervals. Empirical findings reveal a predominant usage pattern of shared bicycles for short-distance travel during both morning and evening peak hours. Notably, distinctive community structures manifest during these periods, characterized by two large communities and multiple smaller ones during the morning peak, while the evening peak showcases a single large community alongside several medium-sized and smaller ones. Moreover, the extended interaction radius points to an expanded geographic range of interactions among streets. These findings bear significant implications for the management of urban transportation, bike-sharing enterprises, and urban residents, proffering valuable insights for the optimization of bike-sharing schemes and transportation strategies. These research findings not only contribute to enhancing urban transportation planning and bike-sharing systems but also provide robust guidance for advancing more efficient and sustainable urban transportation solutions, thereby fostering the sustainable development of cities.

Public preference and acceptability of the travel reservation strategy in Xi'an, China

Time-varying and non-linear associations between metro ridership and the built environment

본 고는 신호교차로 영향권에서 수행되는 도로점용공사가 유발하는 신호교차로의 정지선에서의 유출 가능량, 다시 말해 포화교통류율의 변화를 산정하여 해당 접근 차로군의 용량을 계산할 수 있는 해석적 모형의 개발에 초점을 맞추고 있다. 해석적 모형이 가진 설명력의 간결함과 산정 정확도를 제고하기 위하여 선행연구의 모형논리를 크게 바꾸고 상당한 수정을 가하였다. 또 모형의 검증을 위해서 많은 노력이 보태졌는데, 다양한 미시 모의실험 결과와의 비교 뿐만 아니라 실제 공사현장에서 수집된 많은 자료를 바탕으로 하는 현장 대표 값들과의 비교 등이 수행되었다. 포화교통류율은 도로점용공사의 위치, 정지선과 공사구간과 이격거리, 개방 및 폐쇄 차로 수, 유효녹색시간 등에 상당히 민감하게 변화한다는 것이 확인되었으며, 공사현장의 특성을 구성하는 그와 같은 기하구조 및 신호운영관련 조건 등을 변수로 하는 제안 모형들은 아주 적은 오차 범위 내에서 성공적으로 포화교통류율을 산정해 낼 수 있음을 보여 주었다. This paper focuses on the development of analytical models for estimating the changes in saturation flow rates (SFR) at the stop-lines of a signalized intersection due to the existence of nearby work-zones, and thereby calculating the prevailing capacity values for specific lane groups. Major changes were incorporated in the logics of previous models and significant revisions have been made to secure the accuracy and simplicity. Furthermore, much attention was paid to model validation by making comparisons to both extensive simulation results and empirical data from various sites. It was found that SFRs are highly sensitive to the location of work-zones, the distance to each work-zone from the stop-line of a concerned approach, the number of lanes open and closed, and the effective green time. Using such geometric and operating conditions that constitute work-zone environment, the proposed models successfully estimated SFR values with a miniscule margin of error.

In the modeling of signalized intersections, one parameter is of crucial importance: the saturation flow rate. This value defines the number of vehicles that pass an intersection within 1 h of effective green time per lane. In this study, changes in the saturation flow were investigated under adverse weather conditions, such as precipitation or snow that covered the road surface. Data were obtained from video recordings, and a timestamp was recorded for each vehicle as its rear axle crossed the intersection. Subsequently, all observations were aggregated to a longer time interval. These measurements were then used to train a model by minimizing the squared error between model output and observation. The advantages of the model were the incorporation of various vehicle classes and the consideration of driving behavior at the beginning and the end of the green phase (start and end lags). These parameters were investigated under various weather conditions and showed that the saturation flow rate was significantly influenced by snow on the road surface. To improve traffic models, it is thus important to consider the dependence of the saturation flow rate on the weather. To adjust the saturation flow, adjustments in certain other parameters influenced by prevailing weather conditions were investigated in a microscopic traffic simulation.

The correct saturation flow rates for the specific circumstances must be used to calculate delays and the level of Service at intersections. As a result of a lack of local data, practitioners would often use default values from overseas software developers. Base saturation flow rate is an important factor for timing traffic signals. Despite the 1, 900 pc/h/ln number suggested by the Highway Capacity Manual (HCM), the base saturation flow rate differs from city to city, dependent on the local driving habits and traffic conditions. As a result, it's crucial to estimate, given the local climate. As a result, erroneous decisions may be made that have incorrect results. This study attempts to estimate the base saturation flow rate in Al-Najaf City. The following situations were observed: Turning movement (through or right); Gradient (Up and down); Number of through lanes; and Speed limit (60 and 80 km/h). The mean headway from a total of 9931 through moving vehicles from 187 lineups was calculated to be 1.55. The basic saturation flow rate was therefore determined to be 2, 323 pc/h/ln. This result is substantially higher than the 1, 900 pc/h/ln proposed by the HCM, but it is comparable to results from other nations with similar traffic conditions and driving habits. The results show significant differences between the saturation flow rates when the conditions of the movements are different in terms of the above characteristics. Recommendations are made regarding the most appropriate values to use under different conditions.

Bicycle-sharing is experiencing rapidly as a low-carbon transport mode of travel, with the advantages of low cost and sustainability. Bicycle-sharing operators use electronic fence parking points to manage bicycle-sharing, but it is too time-consuming and impractical to manage them individually. Therefore, it is necessary to cluster the electronic fence parking points and implement regionalized management. This study uses a Mean-shift clustering algorithm to cluster the electronic fence parking points on Xiamen Island, construct a bicycle-sharing dispatching station, and divide the management area. Singular value decomposition is employed to analyze the travel demand patterns of bicycle-sharing and travel characteristics. In addition, we constructed regression models to explore the relationship between the urban built environment and bicycle-sharing trips during the morning and evening peak hours. The study results show that: (1) The 73 dispatching stations constructed cover 86.72% of the bicycle-sharing data, with a good clustering effect. (2) The travel demand for bicycle-sharing shows multiple patterns and different characteristics in different spatial and temporal distributions, which are influenced by land use. (3) There are spatial and temporal differences in the impact of the urban built environment on bicycle-sharing trips, especially residential and enterprise poi densities have opposite effects on shared bicycle-sharing during morning and evening peak hours. The research results of this paper can serve in the planning of bicycle-sharing dispatch stations and the differentiated management and dispatch of bicycle-sharing, which can reduce operating costs and promote the development of sustainable urban transport.

Examining drivers injury severity for manual and automatic transmission vehicles-involved crashes: Random parameter mixed logit model with heterogeneity in means and variances

- Dropped in traffic capacity and travel speed during congestion were studied at a u-turn section on an arterial road in Indonesia. Traffic characteristics during congestion were analyzed using oblique cumulative plots and breakdown method. Both approaches are time series treatment between cumulative vehicles arrival versus time contracted from data recorded by video tape. Studies were conducted in both morning and evening peak hours on three regular weekdays. This study found traffic breakdown condition during the peak periods; the breakdown lasted on average 40 minutes. It was found that capacity during traffic breakdown drops in the range 8-9 percent from the before-breakdown capacity. Similarly, during the breakdown, speed drops on average 10 percent from the before condition. Several alternatives were selected and tested for improving existing conditions. It was found that adding a 50m pocket lane would help improving the existing situation by reducing the delay to 69 percent, increasing speed to 39 percent, and improving capacity to 11 percent compared to the result of simulation an existing condition

The impacts on traffic flows by Fuel Service Stations (FSS) located within 50 m vicinity of four (4) signalized intersections in Kumasi City were assessed. Changes in saturated flow rates, delays and lost times were the im-pact assessment indicators. Reduction in saturation flow rates ranged from low of 2 % to high of 56 %, depend-ing on orientations of the FSS to the intersections. Access to the FSS facilitated circumvention of the intersecti-ons, thereby easing congestion and delays. At one FSS, there was 7.9 % overall reduction in intersection delays, while in the other 3 FSS, the overall intersection delays were increased by 8 - 30 %. The actual lost times excee-ded the allotted signal operational time of 4 s, thereby reducing the effective green times. The existing traffic conditions were simulated for optimal traffic flow using Synchro 6.0 plus Sim Trafficware with traffic flow cha-racteristics, signal control data and geometric features of the intersections as inputs to determine the clearance lost times of critical movements. Comparison of outputs of the simulation runs of existing and control (steady flow states or intersections without FSS) indicated that if the operational signal timings were optimized to com-mensurate the actual lost times, the existing situations would experience reduced delays and congestions.