Transit Priority Strategies Research Articles

Type-2 fuzzy logic based transit priority strategy

We proposed in this paper Type-2 Fuzzy Logic-based transit priority strategy. The developed strategy belongs to the class of active priority strategies. At the same time, it is a conditional priority strategy. We tried to find out the finest trade-off between transit and traffic delay. The suggested approach used the data collected from the VISSIM analysis. The simulation tests were performed on the section of an arterial with two intersections in downtown Belgrade, Serbia. The obtained results are promising. It looks that the developed strategy could improve traffic operations in cities, or areas, with high bus frequencies and/or low or medium traffic volume.

Analytical characterization of multi-state effective discharge rates for bus-only lane conversion scheduling problem

An accurate quantification of traffic flow characteristics with and without bus-only lane is important for determining transit priority strategies. Examinations of real-world vehicle trajectory data, like those from the NGSIM dataset, found that an effective discharge rate may be discounted when merging or lane-changing behaviors are observed. To deal with this, this manuscript analytically derives the effective discharge rate of a roadway segment by considering multi-stage merging behavior and vehicular traffic kinematics near a side entrance, for optimal bus-only lane conversion. The classic fluid-based approximation model by Newell that characterizes the queuing and dissipation process is extended to a multi-state queuing analysis framework. Three effective discharge rate discount factors are explicitly derived, for bus-only lane, general-purpose lane, and mixed-traffic lane, respectively. The derived effective discharge rates are represented by mathematically-simple expressions in a closed-form, and correctly account for the effects of demand inputs, such as arrival rate and the ratio of vehicles of different types, vehicular performance (such as acceleration rate), and traffic flow characteristics (such as backward wave speed and jam density). The bus-only lane conversion scheduling problem is then formulated as an optimization model to minimize total traffic delay. Validation, using NGSIM data, showed that our model reduced the effective discharge rate estimation error significantly on both arterials and freeways. Sensitivity analysis revealed that the optimal bus-only lane scheduling time varied in response to traffic demand and vehicle ratios, and the developed optimization model was always beneficial when compared with the demand-oriented strategy.

Evaluating impacts of intelligent transit priority on intersection energy and emissions

A signal priority strategy (SPS) is implemented to encourage the development of public transportation, but this strategy may delay other vehicles to produce more emissions, especially at intersection. This study aims to develop an intersection energy consumption and emissions model framework with an embedded SPS to analyse the impacts of the SPS on the intersection. To validate this model framework, an intersection in Shenzhen, China was selected for simulation as a case study. In this study, we compared the effects of an active SPS, a real-time SPS and the real-time SPS improved under Intelligent Vehicle Infrastructure Cooperation System (i-VICS) on the energy consumption and emissions of the targeted intersection. The simulation results illustrate that, the active strategy could decrease fuel consumption and emissions with a maximum reduction of 13.33% in fuel consumption, and the real-time strategy maintains a smooth fluctuation in the total fuel consumption and emissions during the entire period. Compared with the two in-use strategies, the i-VICS-based transit priority strategy demonstrates the best environmental performance, by reducing the greatest negative environmental influences and cutting down the most emissions of nearly 28.86% in the case study. The developed intersection energy consumption and emissions model framework can be applied to evaluation of different SPSs on the environment respect, which can benefit to urban transportation management in a more sustainable way.

Bus transit subsidy under China’s transit metropolis initiative: The case of Shenzhen

Transit services are subsidized in various cities. Our article reviews bus transit subsidy in Shenzhen, one of China’s mega cities undertaking tremendous effort to strengthen transit service under the national transit metropolis initiative. The operational data of Shenzhen’s bus transit reveals that the past subsidy policy, which guaranteed 6% of profit, led to significant increase in operational cost per passenger kilometer. The recent switch toward a ridership-based subsidy helps to reverse this trend, but could risk service quality. Shenzhen’s experience has significant implications while China’s city governments implement transit-priority strategies. The gain of social benefit and the loss of operational efficiency have to be carefully balanced when designing subsidy programs.

Hierarchical Colored Petri Nets for Modeling and Analysis of Transit Signal Priority Control Systems

In this paper, we consider the problem of developing a model for traffic signal control with transit priority using Hierarchical Colored Petri nets (HCPN). Petri nets (PN) are useful for state analysis of discrete event systems due to their powerful modeling capability and mathematical formalism. This paper focuses on their use to formalize the transit signal priority (TSP) control model. In a four-phase traffic signal control model, the transit detection and two kinds of transit priority strategies are integrated to obtain the HCPN-based TSP control models. One of the advantages to use these models is the clear presentation of traffic light behaviors in terms of conditions and events that cause the detection of a priority request by a transit vehicle. Another advantage of the resulting models is that the correctness and reliability of the proposed strategies are easily analyzed. After their full reachable states are generated, the boundness, liveness, and fairness of the proposed models are verified. Experimental results show that the proposed control model provides transit vehicles with better effectiveness at intersections. This work helps advance the state of the art in the design of signal control models related to the intersection of roadways.

Evaluating Transit Priority Signal Phasing at Most Multimodal Intersection in Portland, Oregon

This research documents the operational benefits of additional phases, barrier bars, and a call-based transit priority signal-phasing strategy over a more traditional eight-phase, two-barrier preemption-based transit signal–phasing strategy. The call-based timing strategy, with a more flexible ring-and-barrier structure, takes advantage of additional phases to run less-impactful transit prioritization for light-rail trains. These two strategies have been field implemented in Portland, Oregon, at the signalized intersection of Southwest Porter Street and Southwest Moody Avenue, an intersection that has distinct signalized movements for the private-automobile, streetcar, light-rail train, bus, pedestrian, and bicycle modes. The operations of the two-intersection signal-phasing strategies were evaluated and tested by using hardware and software-in-the-loop microsimulation (in Vissim) to isolate the expected change in operational efficiency in modal delay. The two-barrier preemption-based transit signal-phasing strategy showed high variability in delay for certain movements, in particular, pedestrians. The call-based phasing strategy with flexible ring-and-barrier structure reduced total and average intersection delay. This research shows that the call-based phasing strategy with flexible ring-and-barrier structure can provide a less disruptive transit prioritization. Agencies should consider the call-phased transit priority strategy over the more traditional preemption-based strategy at a signalized intersection when ( a) delaying potential preemptive movements mode will not have large safety effects, ( b) pedestrian demand is high, ( c) preemption service will be frequent, or ( d) the intersection is operating at or over capacity.

Estimating modal shift by introducing transit priority strategies under congested traffic using the multinomial logit model

Researchers have been seeking approaches to persuade car users to shift to mass transit through implementing transit priority strategies. Widely used transit priority strategies include a Managed Bus Lane (MBL), transit fare discount, and an increase in parking fees. Most previous studies have focused on the implementation of a single priority strategy, which may not be sufficient enough to induce a significant shift in travel mode. This study aims to investigate the effect of multiple transit priority strategies, also known as multi-strategy, on the travel modal shift of car users. For this purpose, the effects of the three single strategies and the multi-strategy on travel modal shift were compared. A logit model was employed to estimate the choice in travel mode based on the Revealed Preference/stated Preference (RP/SP) data. The findings in this study were compared with those reported in previous studies as well. The results showed that the increase in parking fees has the most influential impact on the travel modal shift of car users, followed by the MBL. Comparatively, a transit fare discount was found to be unattractive for car users to make a change to mass transit. On the other hand, the multi-strategy showed remarkably higher effects on the travel modal shift of car users, but is not a simple superposition of the three single strategies. Additionally, the estimated probability of the shift in transit sharing rate based on RP/SP data was found to be much higher than the actual sharing rate, indicating that the SP data may overestimate the respondents' actual choice.

Evaluation of the pre-detective signal priority for bus rapid transit: coordinating the primary and secondary intersections

Since the traditional transit priority strategy can only adjust signal timing in a limited range and is not suitable for all kinds of signal timing designs, it cannot provide enough priority for Bus Rapid Transit (BRT). In addition, traditional transit priority strategy has caused serious interferences with other traffic. This study proposes a pre-detective signal priority strategy for BRT with coordination between primary and secondary intersections. By pre-detecting, the time buses arrive at the primary intersection, the signal timing of both the primary and secondary intersections, along with the offsets, are adjusted simultaneously, based on the common length and the green ratio of each phase. In this method, the signal cycle constraints are clarified, and the bus control coordination between intersections has been taken into consideration. In this paper, one direction traffic is taken as a study example to testify the effectiveness of this method. The study uses the data collected from Changzhou, China, and a microscopic traffic simulation software PTV VISSIM with four simulation scenarios defined: no signal priority, traditional signal priority, pre-detective signal priority and pre-detective signal priority with coordination. This paper selects a set of indicators to evaluate the traffic operation for both public transit and private traffic. Results show that pre-detective signal priority with coordination is the most effective, with the total bus intersection delay decreases by 67.4% and the bus headway adherence declines by approximately 40% at all the primary and secondary stations of BRT line 1. Moreover, the negative effects that could happen with providing signal priority for BRT, such as increasing the delay and length of queue of private traffic at the intersections, are significantly reduced.

Residents’ Characteristics and Transport Policy Analysis in Large-Scale Residential Areas on a City Periphery

Big cities in China are reforming their old downtown areas and demolishing substandard housing. The government relocates residents to large-scale residential areas on the city periphery, where the residents often find transport service unsatisfactory. However, in the search for policies that could be applied to ease this problem, there were no studies supplying effective quantitative forecasts that assessed improvements in travel quality in such areas. To provide a policy scenario forecast that could measure travel quality, one that is also subject to the so-called transit priority strategy, this study takes the case of Jinhexincheng, Shanghai, China, analyzes its residents’ characteristics, estimates a mode choice mixed logit model, and applies the model to six policy scenario forecasts. Consumer surplus is calculated as the travel quality metric; mode shares are calculated as the transit priority metric. Results show that central city migrants and the others are similar in gender, education, years living locally, and transportation-related decisions, despite their different motives for moving to the area. People are different in age, in whether they have Shanghai permanent residency, in apartment ownership, and in years living in Shanghai. In all possible mode choice logit models, there is no sign of different mode preferences; so in the policy scenario forecasts, they are considered the same. Of all six sets of possible policy scenarios, building retail closer has the highest consumer surplus increase—thus, it improves travel quality the most. Meanwhile, it also has an acceptable transit share. This means the scenario is not against transit priority. In future planning, this policy should be the first considered.

Transportation Model Application for the Planning of Low Carbon City – Take Xining City in China as Example

The low carbon development is the important trend of Chinese urbanism, and the gap between transportation infrastructure resource and travel demand induces to the transportation problems, such as congestion, energy, and safety. There is a missing connection with the Demand-Oriented Planning and Low-Carbon-Oriented Planning, since most of our discussion in the Urban Comprehensive Planning Proceed is focusing on the commuting congestion in the peak hour. This paper discussed the benefits and problems of the three solutions of transportation, based on the Transit Priority Strategy in China, including the transportation policy research, smart transportation research, as well as planning and design research. A further Model exploration and application for the smart low-carbon transit and non-motorized transportation system construction strategic decision making is discussed. The result shows around 30% energy consumption and CO2 emission could be waived if we choose the low-carbon city development mode. The solution and case study apply the Unit City mode and City Intelligent Energy Network technology in Xining City Comprehensive Planning to find out how to form the future development in the cities in China.

Transit Priority Strategies for Multiple Routes under Headway-Based Operations

This paper presents a transit signal priority (TSP) model designed to consider the benefits both to bus riders and to intersection passenger car users. The proposed strategy, which is mainly for headway-based bus operations, offers the responsible agency a reliable way to determine the optimal green extension or red truncation duration in response to multiple bus priority requests from different routes. The control objective is to minimize bus passenger waiting time at the downstream bus stop while ensuring that the delays for all passengers are not increased. In tests that used field data from Jinan, China, the proposed strategy showed promise in reducing bus passenger waiting time and total intersection delay. Further exploration with simulation experiments for sensitivity analysis found that TSP is most effective if the ratio between bus and passenger volumes exceeds a threshold of 2%.

Transit Priority Strategies for Multiple Routes under Headway-Based Operations

This paper presents a transit signal priority (TSP) model designed to consider the benefits both to bus riders and to intersection passenger car users. The proposed strategy, which is mainly for headway-based bus operations, offers the responsible agency a reliable way to determine the optimal green extension or red truncation duration in response to multiple bus priority requests from different routes. The control objective is to minimize bus passenger waiting time at the downstream bus stop while ensuring that the delays for all passengers are not increased. In tests that used field data from Jinan, China, the proposed strategy showed promise in reducing bus passenger waiting time and total intersection delay. Further exploration with simulation experiments for sensitivity analysis found that TSP is most effective if the ratio between bus and passenger volumes exceeds a threshold of 2%.

Study of Transit Priority Strategies on Intersection under Multi-Restrictions

Recent years, traffic congestion is evolved into an urban disease that rejects to the urban development. Besides, it also makes multiples of exhaust pollution. To release this problem, the most effective way is to develop public transport. This paper established a model (PI) of transit priority strategies based on delay, queue length, quantities of wait vehicles, fuel consumption, CO emission, and HC emission. Among them, fuel consumption, CO emission, and HC emission are environment elements that added to this paper for the first time. After that, an evaluation is made based on cellular automata simulation, showing that the efficiency is improved by 17.7 percents when using multi-restrictions transit priority strategies, compared to that without any transit priority strategies.

Calculating Model of Urban Public Transit Subsidy

Urban public transit financial subsidy is one of the key links, which promote public transit priority strategies. It is an important issue of urban traffic sustainable development to establish a specific operable subsidy calculating model and to improve the way to calculate urban public transit subsidy. This study establishes the game model among the income of residents, enterprises operating costs, and subsidies through utility theory. It shows the advantages of classification subsidy of public transit riders and establishes a specific operable subsidy calculating model. Then, the calculation of Beijing public transit subsidies in 2007 is taken as an example. The results indicate that the subsidy classification and the subsidy calculating model not only can fully satisfy the travel demands of public transit riders but also can effectively calculate the subsidy amount, which realizes the utility maximization of government subsidy. The proposed method is proved to be a new effective way to measure urban public transit subsidy.

Evaluation of Potential Transit Signal Priority Benefits along a Fixed-Time Signalized Arterial

This paper presents the findings of a study evaluating the potential benefits of implementing transit signal priority along the Columbia Pike arterial corridor, in Arlington, Va. The study uses the \IINTEGRATION\N microscopic traffic simulation model to evaluate the impact of a number of alternative priority strategies on both the prioritized buses and general traffic during the morning peak and midday traffic periods. The transit priority strategies considered include providing priority to express buses traveling along Columbia Pike, to both express and regular buses along the arterial, and to all buses within the study corridor. The priority logic that is considered in the study provides simple green extensions and green recalls within a fixed-time traffic signal control environment. The simulation results indicate that the buses provided with priority would typically benefit from transit priority, but that these benefits may be obtained at the expense of the overall traffic, particularly when traffic demand is high. However, it is also found that in periods of lesser demand, the overall negative impacts could be negligible due to the availability of spare capacity at the signalized intersections.

Control Strategies for Transit Priority

Control strategies for transit priority have long been recognized as having the potential to improve traffic performance for transit vehicles, which could also lead to improved schedule reliability, reduced operating costs, and greater ridership. However, there have been relatively few successful implementations of transit priority measures on urban networks with signalized intersections in coordinated signal systems. Existing control strategies are reviewed, the major factors affecting transit priority are identified, and the formulation of both passive and active transit priority strategies for arterials with coordinated traffic signals are described. The proposed strategies were evaluated on a real-life arterial corridor. The proposed passive and active priority strategies placed major emphasis on the systemwide improvements to the transit movements and on minimization of the adverse impacts to the rest of the traffic stream. The criteria used to grant priority include the availability of spare green time in the system cycle length, progression at the downstream intersection(s), and schedule adherence. An evaluation technique was also developed to assist in the design of the signal priority strategies and to predict the impacts of the transit priority measures.