Estimating the Impacts of Bus Stops and Transit Signal Priority on Intersection Operations: Queuing and Variational Theory Approach

2017 ◽  
Vol 2622 (1) ◽  
pp. 70-83 ◽  
Author(s):  
Kan Wu ◽  
S. Ilgin Guler ◽  
Vikash V. Gayah
Keyword(s):  
Queuing Theory ◽  
Theory Approach ◽  
Transit Signal Priority ◽  
Variational Theory ◽  
Traffic Conditions ◽  
Bus Stop ◽  
Car Traffic ◽  
Trade Offs ◽  
Bus Delay ◽  
Local Agencies

Transit signal priority (TSP) can be used to improve bus operations at signalized intersections, often to the detriment of general car traffic. However, the impacts of TSP treatments applied to intersections with nearby bus stop locations are currently unknown. This paper quantifies changes in intersection capacity, car delay, and bus delay when priority is provided to buses that dwell at near- or farside bus stop locations through green extension or red truncation. Variational and kinematic wave theories are used to estimate car capacity and bus delay for oversaturated traffic conditions; queuing theory is used to estimate car and bus delays for undersaturated conditions. Numerical analyses are conducted to explore the impacts on various bus stop locations and bus dwell time durations. These results illustrate clear trade-offs between reduced bus delays and increased car delays or reduced intersection capacities that can be quantified with the proposed method. The results also reveal that the effects of TSP vary dramatically with bus dwell times for a given bus stop location. The proposed method and associated results can be used to implement TSP strategies to meet the specific needs of local agencies.

scholarly journals IoT based Real Time Traffic Monitoring System Using M/G/1 Queuing Research

2019 ◽  
Vol 8 (6) ◽  
pp. 3818-3822
Keyword(s):  
Intelligent Transportation Systems ◽  
Traffic Congestion ◽  
Queuing Theory ◽  
Traffic Monitoring ◽  
Transportation Systems ◽  
Theory Approach ◽  
The Road ◽  
Traffic Conditions ◽  
Performance Framework ◽  
Real Time Traffic

Vehicular Traffic crowding is paramount worry in urban cities. The use of technologies like Intelligent Transportation systems and Internet of Things can solve the problem of traffic congestion to some extent. The paper analyses the traffic conditions on a particular urban highway using queuing theory approach. It researches on performance framework such as time for waiting and queue length. The results can provide significant analysis to predict traffic congestion during peak hours. A congestion controlling action can be generated to utilize the road capacity fully during peak hours by using these results

Performance of Transit Signal Priority with Queue Jumper Lanes

2005 ◽  
Vol 1925 (1) ◽  
pp. 265-271 ◽  
Author(s):  
Guangwei Zhou ◽  
Albert Gan
Keyword(s):  
Transit Signal Priority ◽  
Preferential Treatment ◽  
Local Conditions ◽  
Bus Stop ◽  
Optimal Detector ◽  
Bus Delay ◽  
Traffic Volumes ◽  
Bus Stops ◽  
Detector Location

Queue jumper lanes are a special type of bus preferential treatment that allows buses to bypass a waiting queue through a right-turn bay and then cut out in front of the queue by getting an early green signal. The performance of queue jumper lanes is evaluated under different transit signal priority (TSP) strategies, traffic volumes, bus volumes, dwell times, and bus stop and detector locations. Four TSP strategies are considered: green extension, red truncation, phase skip, and phase insertion. It was found that queue jumper lanes without TSP were ineffective in reducing bus delay. Queue jumper lanes with TSP strategies that include a phase insertion were found to be more effective in reducing bus delay while also improving general vehicle operations than those strategies that do not include this treatment. Nearside bus stops upstream of check-in detectors were preferred for jumper TSP over farside bus stops and nearside bus stops downstream of check-in detectors. Through vehicles on the bus approach were found to have only a slight impact on bus delay when the volume-to-capacity (v/c) ratio was below 0.9. However, when v/c exceeded 0.9, bus delay increased quickly. Right-turn volumes were found to have an insignificant impact on average bus delay, and an optimal detector location that minimizes bus delay under local conditions was shown to exist.

Optimizing Transit Signal Priority Implementation along an Arterial

2018 ◽  
Vol 2672 (20) ◽  
pp. 215-227 ◽  
Author(s):  
Kan Wu ◽  
S. Ilgin Guler
Keyword(s):  
Travel Time ◽  
Case Studies ◽  
Signalized Intersections ◽  
Transit Signal Priority ◽  
Variational Theory ◽  
Marginal Costs ◽  
Optimization Framework ◽  
Bus Delay ◽  
Car Travel ◽  
Multiple Intersections

Transit signal priority (TSP) is a common method of providing priority to buses at signalized intersections. The implementation of TSP can affect travel time of cars traveling in the same, opposite, and cross directions. The bus delay savings and car travel-time impacts are not expected to increase linearly when considering multiple intersections along an arterial. This paper quantifies the influence of TSP on arterials with dedicated bus lanes considering an arterial-wide approach utilizing variational theory. Existing tools were modified to quantify the change in capacity along an arterial where TSP was implemented and it was shown that this effect was negligible. In addition, the bus delay savings and cross-street capacity losses were determined. Case studies provided insights into the influence of TSP among different network homogeneities and bus frequencies. Using these tools, an optimization framework was developed to determine where to implement TSP along an arterial to maximize the marginal benefits, or minimize marginal costs. In addition, a comparison of evaluating an arterial as a sum of isolated intersections as opposed to evaluating an arterial as a whole is presented. This analysis indicates the necessity of the arterial-based method in considering TSP impacts along corridors.

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

2021 ◽  
pp. 036119812110302
Author(s):  
Chao Wang ◽  
Weijie Chen ◽  
Yueru Xu ◽  
Zhirui Ye
Keyword(s):  
Approximation Method ◽  
Service Time ◽  
Diffusion Approximation ◽  
Coefficient Of Variation ◽  
Queuing Theory ◽  
Queuing Model ◽  
Bus Stop ◽  
Proposed Model ◽  
Bus Stops ◽  
Bus Service

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.

Does Combining Transit Signal Priority with Dedicated Bus Lanes or Queue Jump Lanes at Multiple Intersections Create Multiplier Effects?

2017 ◽  
Vol 2647 (1) ◽  
pp. 80-92 ◽  
Author(s):  
Long T. Truong ◽  
Graham Currie ◽  
Mark Wallace ◽  
Chris De Gruyter
Keyword(s):  
Public Transport ◽  
Policy Implication ◽  
Transit Signal Priority ◽  
Time And Space ◽  
Multiplier Effect ◽  
Bus Delay ◽  
Simulation Results ◽  
Multiplier Effects ◽  
Extensive Body ◽  
Multiple Intersections

An extensive body of literature deals with the design and operation of public transport (PT) priority measures. However, there is a need to understand whether providing transit signal priority with dedicated bus lanes (TSPwDBL) or transit signal priority with queue jump lanes (TSPwQJL) at multiple intersections creates a multiplier effect on PT benefits. If the benefit from providing priority together at multiple intersections is greater than the sum of benefits from providing priority separately at each of those individual intersections, a multiplier effect exists. This paper explores the effects of providing TSPwDBL or TSPwQJL at multiple intersections on bus delay savings and person delay savings. Simulation results reveal that providing TSPwDBL or TSPwQJL at multiple intersections may create a multiplier effect on one-directional bus delay savings, particularly when signal offsets provide bus progression for that direction. The multiplier effect may result in a 5% to 8% increase in bus delay savings for each additional intersection with TSPwDBL or TSPwQJL. A possible explanation is that TSPwDBL and TSPwQJL can reduce the variations in bus travel times and thus allow signal offsets—which account for bus progression—to perform even better. Furthermore, results show little evidence of the existence of a multiplier effect on person delay savings, particularly for TSPwQJL with offsets that favor person delay savings. A policy implication of these findings is that considerable PT benefits can be achieved by providing both time and space priority in combination on a corridorwide scale.

scholarly journals Heart Failure Care Transitions: A Queuing Theory Approach to Quantify the Impact of Vacation Periods on Discharge Clinic Wait Times

2016 ◽  
Vol 22 (8) ◽  
pp. S133
Author(s):  
R. Kannan Mutharasan ◽  
Preeti Kansal ◽  
Hannah Alphs Jackson ◽  
Corrine Benacka ◽  
Robin Fortman ◽  
...  
Keyword(s):  
Heart Failure ◽  
Queuing Theory ◽  
Care Transitions ◽  
Wait Times ◽  
Theory Approach ◽  
Heart Failure Care ◽  
The Impact

scholarly journals Perimeter Control as an Alternative to Dedicated Bus Lanes: A Case Study

2018 ◽  
Vol 2672 (20) ◽  
pp. 110-120 ◽  
Author(s):  
Nicolas Chiabaut ◽  
Michael Küng ◽  
Monica Menendez ◽  
Ludovic Leclercq
Keyword(s):  
Traffic Management ◽  
Transit System ◽  
Control Approach ◽  
Traffic Conditions ◽  
Car Traffic ◽  
Traffic Performance ◽  
Objective Control ◽  
Queue Lengths ◽  
Urban Arterial

Dedicated bus lanes (DBLs) are a common traffic management strategy in cities as they improve the efficiency of the transit system by preventing buses from getting trapped in traffic jams. Nevertheless, DBLs also have certain disadvantages: they consume space, reduce available capacity for general traffic, and can thus lead to even more congested car traffic situations. It is appealing to find more efficient alternatives that maintain a sufficient network supply for general traffic while guaranteeing high commercial speeds for the bus system. This paper investigates whether perimeter control (gating) could be such an alternative to DBL strategies. This solution aims at controlling the traffic conditions of a given area by monitoring vehicle accumulations and adapting traffic signal parameters to reach the targeted conditions. If free-flow states can be maintained within the zone, then DBLs become superfluous. This hypothesis is examined through a simulation case study with an urban arterial acting as the targeted area. A dual-objective control approach was applied to allow for not only the vehicle accumulation inside the area but the queue lengths at its perimeter, thereby addressing one of the main issues associated with gating schemes. Due to the gating strategy, traffic performance in the arterial, measured through vehicle accumulation plus mean speed and density, improved significantly. Moreover, results showed that bus operations reach almost the same efficiency level when DBLs are replaced by perimeter control. Furthermore, the availability of an additional lane for general traffic in the control case significantly increased the arterial capacity for cars.

INFLUENCE OF BUS BAY AND CURBSIDE BUS STOP IN AN URBAN ROAD

2020 ◽  
Vol 8 (3) ◽  
pp. 14-19
Author(s):  
Saurav Barua
Keyword(s):  
Traffic Congestion ◽  
Simulation Models ◽  
Good Alternative ◽  
Road Segment ◽  
Dhaka City ◽  
Average Speed ◽  
Urban Road ◽  
Traffic Conditions ◽  
Bus Stop ◽  
Bus Stops

Purpose of Study: The purpose of this study is to investigate the efficiency of bus bay compare to the curbside bus stop in a midblock road segment of Dhaka city. Methodology: Vehicle composition and traffic volume were counted on-peak hours for the midblock of Azimpur road near the existing bus stop. Simulation models were developed in VISSIM, where Model 1 represented the existing road scenario with curbside bus stop, and Model 2 represented the same road segment with a bus bay. Main findings: The simulation result showed that Model 2 outperformed Model 1 due to the presence of bus bay. Comparing Model 1, travel time and delay reduced by varying 1.80% to 12.5% and 6.25% to 100% respectively in Model 2 during the simulation. Similarly, average speed increased by 1.39% and density decreased by 61.29% in model 2. Application of this study: Curbside bus stops result in abrupt halt, disrupt traffic flow, and queuing of the small-sized vehicle behind buses. These bus stops caused traffic congestion and delays in urban roads which can be alleviated by alternatives, such as, bus bay. The novelty of this study: The bus bay is a good alternative to the curbside bus stop, which can improve existing traffic conditions in urban roads.

The impact of dwell time variability on transit signal priority performance

2014 ◽  
Vol 41 (2) ◽  
pp. 154-163 ◽  
Author(s):  
Mohammad S. Ghanim ◽  
Francois Dion ◽  
Ghassan Abu-Lebdeh
Keyword(s):  
Control Strategy ◽  
Dwell Time ◽  
Signalized Intersections ◽  
Time Variability ◽  
Transit Signal Priority ◽  
Operational Control ◽  
Priority Systems ◽  
Bus Delay ◽  
Transit Agencies ◽  
The Impact

Transit signal priority (TSP) is an operational control strategy that provides preferential treatments for transit vehicles at signalized intersections. Many transit agencies are currently considering the implementation of priority systems providing buses with preferential treatments at signalized intersections. While studies have demonstrated potential bus delay reductions, none has attempted to identify the problems posed by variable dwell times at bus stops. This study identifies the impacts of variable dwell times on the efficiency of transit signal priority systems. Results also show that, in general, variable dwell times negatively affect the TSP performance. However, and contrary to expectations, a number of scenarios with variable dwell times resulted in lower average bus delays than scenarios with fixed dwell times. These results are attributed to changes in progression and bus arrival patterns under variable dwell times resulting in an increasing number of buses arriving close enough to benefit from preferential treatments.

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