Bus Stop Capacity Research Articles

Performance evaluation of bus stops on arterial roads in Hanoi city

The operations of critical bus stops on arterial roads substantially influence the facility bus capacity and the bus quality of service in terms of schedule reliability. The aim of this article is to employ the methodology in the Transit Capacity Quality of Service Manual (TCQSM) to better understand the performance of key bus stops on arterial roads in Hanoi city. The obtained results shown that the capacities of most examined bus stops (Bus Stops 02, 03, and 04) are considerably lower than the actual demands of buses on the considered roads, and increasing the number of loading areas at bus stops is one of the feasible solutions to effectively improve the capacity of bus stops in Hanoi city. The results achieved provide urban transport management agencies and public transport practitioners in Vietnam with a valuable tool for bus stop capacity measurement and additional information for bus quality of service improvement

Impacts of bus overtaking policies on the capacity of bus stops

Long bus queues at busy stops plague bus systems in many cities. Since berths are laid-out in tandem, buses’ overtaking maneuvers are often prohibited or restricted, which can significantly reduce a bus stop’s discharge capacity. When overtaking is allowed, aggressive drivers may perform disruptive oblique insertion maneuvers that would undermine stop capacity and compromise safety. This paper develops parsimonious yet realistic simulation models to examine the impacts of different overtaking policies on bus-stop capacity. Key realistic features are considered, including the oblique insertions resulting from overtaking, impacts of a nearby traffic signal, and bus traffic characteristics (reaction and move-up times). Extensive numerical experiments unveil many new findings. Some are at odds with those reported by previous studies. In addition, we examine two strategies that can improve the stop capacity without incurring disruptive oblique insertions. Practical implications of our findings are discussed, especially on choosing the most productive overtaking policy and means to minimize the capacity lost to buses’ mutual blockage at stops. These implications have broad applications to various types of bus stops.

Modeling Bus Capacity for Bus Stops Using Queuing Theory and Diffusion Approximation

For bus service quality and line capacity, one critical influencing factor is bus stop capacity. This paper proposes a bus capacity estimation method incorporating diffusion approximation and queuing theory for individual bus stops. A concurrent queuing system between public transportation vehicles and passengers can be used to describe the scenario of a bus stop. For most of the queuing systems, the explicit distributions of basic characteristics (e.g., waiting time, queue length, and busy period) are difficult to obtain. Therefore, the diffusion approximation method was introduced to deal with this theoretical gap in this study. In this method, a continuous diffusion process was applied to estimate the discrete queuing process. The proposed model was validated using relevant data from seven bus stops. As a comparison, two common methods— Highway Capacity Manual (HCM) formula and M/M/S queuing model (i.e., Poisson arrivals, exponential distribution for bus service time, and S number of berths)—were used to estimate the capacity of the bus stop. The mean absolute percentage error (MAPE) of the diffusion approximation method is 7.12%, while the MAPEs of the HCM method and M/M/S queuing model are 16.53% and 10.23%, respectively. Therefore, the proposed model is more accurate and reliable than the others. In addition, the influences of traffic intensity, bus arrival rate, coefficient of variation of bus arrival headway, service time, coefficient of variation of service time, and the number of bus berths on the capacity of bus stops are explored by sensitivity analyses.

Incorporating Practical Degree of Saturation in Capacity Estimation of On-Street, Mid-Block, Off-Line Bus Stops

The effectiveness of an on-street bus facility depends on the general traffic that shares the lane used by buses. The Transit Capacity and Quality of Service Manual (TCQSM) methodology was used to estimate facility bus capacity based on critical stop operation. Hisham et al. provided an improved understanding of performance of an on-street, mid-block, off-line bus stop by relating bus stop capacity to the adjacent lane traffic flow rate. Using the TCQSM methodology, bus stop capacity was determined by adopting an estimated operation margin that relates to a design bus stop failure rate. However, failure rate is theoretically ambiguous and difficult to quantify in practice, particularly under high volume traffic conditions. In contrast, degree of saturation is a direct measure of operating conditions experienced by buses using the stop, and by the adjacent lane general traffic, so it directly affects approach delay and queuing. The aim of this study was to better understand performance at on-street, mid-block, off-line bus stops by considering degrees of saturation of loading areas and the adjacent lane rather than design failure rate according to the TCQSM methodology, and to ensure that waiting times upstream of bus stops are kept to acceptable levels by determining bus stop maximum working capacity.

Diffusion approximation for exploring the correlation between failure rate and bus-stop operation

ABSTRACTThis study proposed a model incorporating a diffusion approximation method to explore the correlation between failure rate and bus-stop operation, which included bus arrival rate, service time, variation coefficient of service time, variation coefficient of bus arrival headway, and bus stop capacity. According to the results, the linear relationship had more accurate and reliable fitted values (with 6.98% of MAPE and 0.935 of R-square) for single-berth stops and the exponential relationship had better performance (with 0.799 of R-square and 14.86% of MAPE) for multi-berth stops to explore the expression of failure rate. The results of sensitivity analyses showed that failure rate increased with the increasing ratio of arrival rate to service rate, and added berths produced diminishing returns in failure rate and capacity. In addition, the returns in capacity were influenced by failure rate, and variation coefficients of bus arrival headway and service time.

Performance Analysis of Overtaking Maneuvers at Bus Stops with Tandem Berths

Bus queues are common at bus stops and may cause significant delays. Overtaking is a standard maneuver used by buses at curbside stops. In general, there are two kinds of overtaking maneuvers, namely overtaking in and overtaking out. When overtaking is allowed, the analysis of the bus queues becomes more difficult because such maneuvers violate the first-in, first-out rule and affect the capacity of the bus stop as well as the average waiting delay. It is important to understand the effects that overtaking maneuvers have on the operations at bus stops. In our study, we consider four different bus overtaking rules at curbside bus stops and analyze four associated queuing models with finite tandem berths. To be more specific, low, moderate, and high bus frequencies are analyzed assuming exponentially distributed dwell times. Analytic expressions for the expected average waiting delays are developed. Further, a general queueing model with overtaking maneuvers occurring at random is presented. Through simulation, the accuracy of the models and the effects of the coefficient of variation of the dwell times on waiting delays are examined. Theoretical analyses as well as simulation results show the positive effects of overtaking maneuvers on the bus stop capacity and on expected average delays at curbside stops when dwell times are varied. The comparison of different overtaking maneuvers reveals performance differences among the various rules and shows why buses should rather be encouraged to overtake when departing a stop than when entering it. In addition, we discuss some practical factors that may impede the implementation of overtaking. Some managerial insights are obtained, and our formulations and results may help with the assignments of bus lines to bus stops and bus frequency-setting problems. The online appendix is available at https://doi.org/10.1287/trsc.2018.0841 .

Capacity Estimation of On-Street, Mid-Block, Off-Line Bus Stops Considering Yield-to-Bus Rule

The effectiveness of an on-street bus facility depends on the volume of general traffic sharing the buses’ travel lane. The Transit Capacity and Quality of Service Manual (TCQSM) methodology estimates capacity of a bus facility based on the operation of critical stops. The aim of this study is to understand better the performance of an on-street, mid-block, off-line bus stop by relating bus stop capacity to adjacent lane traffic volume. The contributions of this paper are twofold. First, the TCQSM methodology incorporates the effect of adjacent lane traffic volume on bus stop capacity at mid-block bus stops through its effect on re-entry delay, but it does not consider the impact of the bus stop itself on adjacent lane traffic capacity. This paper introduces a novel methodology to estimate the additional time required to accommodate adjacent lane traffic volume under saturated conditions. Second, the TCQSM methodology does not reflect the effect on re-entry delay of a yield-to-bus (YTB) rule, which is mandatory by law in some jurisdictions. This paper modifies the current TCQSM methodology by allowing for the YTB rule. A microscopic simulation model is developed in order to cross-validate the theoretical model developed.

Variable Signal Progression Bands for Transit Vehicles Under Dwell Time Uncertainty and Traffic Queues

Signal priority controls have long been viewed as one of the viable strategies to minimize bus delays at intersections so as to reduce the travel time variability or increase headway stability. Such control strategies, however, are often not effective for arterials serving heavy bus flows, because frequent signal priority calls will inevitably disrupt the arterial signal plan and incur excessive delays to general traffic. To overcome such deficiencies, this paper presents a bus-based signal progression model for arterials with heavy bus flows as in most major cities in Asia and Europe. The proposed model features its properties of accounting for the impacts of average bus dwell time, its variance, and the bus stop capacity. The impacts of various upstream traffic flow rates and signal plans on the available bus progression band have also been included in computing the optimal bus-progression offsets. Extensive simulation experiments have confirmed the effectiveness of the computed bus progression bands under various traffic congestion levels. The proposed bus-based pre-timed signal system can serve as a base plan for real-time operations of priority control for bus progression if the congestion level on the arterial or dwelling time variance as well as traffic queues have exceeded the operational capacity of the bus-based progression system.

Modeling loading area effectiveness at off-line bus stops with no clear-cut separation of berths

ABSTRACTThe loading area effectiveness is a key factor for the estimation of the bus stop capacity. The basic assumption of the existing studies is that the berths of the bus stop are divided clearly. In this paper, a new loading area effectiveness model is proposed for computing the number of effective loading areas of the off-line bus stops that have no clear-cut separation of berths. The key parameters, including the critical overtaking exiting distance gap, critical overtaking entering distance gap, and dwelling space-gap between two adjacent buses were calibrated by field data. A simulation-based approach is applied to solve the model. The proposed model was validated and the sensitivity analysis of main factors were also conducted. The results reveal that the driving behavior plays an important role. On average, 4.1% increase in the loading area effectiveness can be obtained by one meter decrease of the critical overtaking entering space-gap.

Bus Capacity Estimation using Stochastic Queuing Models for Isolated Bus Stops in China

When serving passengers at a bus stop, a dwelling bus may cause a bottleneck that constrains traffic flow near the bus stop. A major element in bus system capacity is bus stop capacity (veh/h). Therefore, this study proposes a method estimating the capacity of bus stops isolated from the influences of traffic signals and other bus stops. Data collected for the seven most common bus stop configurations in China were used to validate the proposed model. The results indicated that the arrival process obeys a Poisson distribution and the service times fit a lognormal distribution. Stochastic queuing models for both single-berth and multi-berth stops were developed to estimate bus stop capacity and bus delay time. To enable comparison, the Highway Capacity Manual (HCM) model for bus stop capacity estimation was also used. The results showed that the proposed method was more accurate and reliable, with a mean absolute percentage error (MAPE) of 8.44% compared with a MAPE of 17.42% from the HCM method. In addition, the proposed method reduced root mean squared error (RMSE) by 58.8%, mean absolute error (MAE) by 57.9%, and variance of absolute percentage error (VAPE) by 52.6% compared with the values from the HCM model. Sensitivity analyses were also conducted to investigate the effects of bus arrival rate, bus service time, and the number of bus berths on the capacity of bus stops. The results indicated that the proposed method can be used as a guide for designing bus stop facilities under specified conditions.

Bus Stop and Bus Terminal Capacity

Stockholm is growing fast leading to an increased demand for public transport services and facilities. This has subsequently led to challenges to provide suitable bus terminals. The Municipalities are keen to provide good public transport but have difficulties providing the needed space. There is also a lack of knowledge in this problem area. A comprehensive study is therefore undertaken including literature review, field studies and modeling of the capacity of different types of bus stops and bus terminals.In order to understand and evaluate the capacity of the bus terminals, the starting point is the capacity of loading areas for which there is presently no approved Swedish methodology. A model of capacity based on bus dwell time described by HCM2000 has therefore been used. This model does not consider the bus arrival distribution; therefore it has been applied with a correction factor to better reflect conditions in large cities. Results from performed trials show that this correction factor is reduced at higher dwell time.The calculation of loading areas capacity is the basis for the calculation of bus stop capacity in bus terminals. However, terminal factors such as scheduling and design of the terminals must be taken into account. The procedure for estimating the maximum number of bus departures is also handled in the study. In the long term deeper analysis will be required, e.g. the need for safety zone behind the reversing buses and the demand for dedicated places for layover parking. Socio-economic analyzes of congestion and longer detours because of the increasingly smaller bus terminals should also be raised in these discussions.

Analytical model for calibrating delay at congested bus stops

A model is proposed to calculate the overall operating and delay times spent at bus stops due to passenger boarding and alighting and the time lost to queuing caused by bus stop saturation. A formula for line demand at each stop and the interaction between the buses themselves is proposed and applied to different bus stops depending on the number of available berths. The application of this model has quantified significant operational delays suffered by users and operator due to consecutive bus arrival at stops, even with flows below bus stop capacity.

BUS BAY PERFORMANCE AND ITS INFLUENCE ON THE CAPACITY OF ROAD NETWORK IN DAR ES SALAAM

One of major problems facing motorists in Dar es Salaam city today is congestion. Bus bays have a significant influence on the capacity of a roadway because they interfere with passing vehicles primarily when buses maneuver to pull into and out of bus bays. Bus bay stops will also interfere with vehicles movement if bus demand exceeds the bus bay capacity resulting in some buses waiting in the travel lane until the buses occupying the bay exit the bay. This paper presents the results of a study which was carried out to evaluate the bus bay performance and its influence on the capacity of the roadway network in the city of Dar es Salaam. The case study area covered 11 bus stops along Morogoro road from Ubungo to Magomeni Mapipa. Capacity of bus bays was studied using procedure outlined in the Transit Capacity and Quality of Service Manual of 2003. This enabled the researcher to determine parameters such as dwell times and clearance times which are major determinants of bus stop capacity. The results indicate that only 18% of the bus bay stops studied did not have adequate capacity to cater for the available demand. 9% did not have adequate capacity during peak hours but the capacity was adequate during off-peak hours. The remaining 73% of bus bay stops possess adequate capacity all the time. Although most bus bay stops studied possess adequate capacity, severe congestion was observed at these locations. This is due to erratic behavior of bus drivers who do not utilize the provided space for them to drop off and pick up passengers. Clearly, this is an area that requires more strict enforcement in order to ease the congestion problem in the city by operating the existing capacity more efficiently.