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Introduction.Recently, in large and medium-sized cities, the increase in traffic has been exacerbated by the growth of motorization and the lack of development of the road network. Increasing vehicle traffic to a critical level leads to overcapacity of the arteries and, as a consequence, increases the level of delay. Public urban mass passenger transport is one of the most vulnerable groups in this regard. In order to unload the city’s street network, it is necessary to reduce the level of road traffic. One of the effective measures to deal with this problem is to increase the attractiveness of urban mass passenger transport, i.e. to ensure an adequate level of service for passengers including high speed, which can be increased by giving priority to bus traffic. One of the prospects for prioritizing public urban transport is the development of individual lanes or streets for urban rolling stock only. Due to the lack of criteria for the allocation of separate lanes for urban rolling stock, they have begun to appear in the vast majority on the main streets of the city. There are a large number of urban highways used for the operation of only one public transport route with dedicated lanes on them. The need for such arrangements is questionable. It is therefore necessary to formulate the criteria that justify the need for a separate urban passenger lane on a given stretch of the city network. Thus, the purpose of this work is to identify patterns between traffic parameters and the parameters of the urban public passenger transport programme, which will determine the criteria for the need for a separate lane for urban land transport on each individual stretch of the network.Materials and methods.This article deals with the method of determining the need for a separate lane for public urban passenger transport on a given stretch of the road network. In order to improve the quality of the transport of passengers, a mathematical model has been developed, based on such indicators as the level of traffic delay and the share of passenger traffic in the total flow of participants. Results. The necessary conditions have been laid down the strict implementation of which determines the need to ensure the priority of urban mass public passenger transport on the section of the city’s street network under consideration.Discussion and conclusion.The dependencies obtained make it possible to identify the need to ensure the priority of urban transport. more...

The article is devoted to the methodology and research results of traffic flow parameters on the arterial streets, where different regimes of prioritizing urban public transport operate. The regularities of changes of such parameters make it possible to identify and differentiate the sections of transport network in terms of service efficiency, with the aim to implement various regulatory measures that would help to minimize delays in traffic flow. Quantitative and qualitative criteria for ensuring priority transit of urban public transport on different sections of transport network depending on the intensity, speed and composition of traffic, as well as the roadway parameters are defined and substantiated. According to the research outcomes, scientifically based approaches are recommended for the implementation of different schemes of traffic flows control on the sections of the transport network, which differ in planning parameters and of traffic conditions and provide rational transport service based on the criterion of time loss for movement of residents. These results are adequate for large and very large cities with dense construction area more...

Traffic congestion is a major problem in developing country like Nigeria. Traffic congestion at intersection is on the increase in Auchi metropolis as the numbers of vehicles increases there, which eventually lead to traffic delay and traffic crash casualties. For this research, an Markovian/Markovian/1 (M/M/1) queuing model was used to analyse the queuing characteristic of the intersection to determine the arrival rate and service rate of the vehicles. An operation research software known as Temporary-Ordered Routing Algorithm (TORA) version 2.5 was used to analyze the arrival and service time data obtained to determine the operating characteristics of the M/M/s model for each of the intersection. The result showed that the average traffic intensity of the intersections was more than the optimal traffic intensity of 0.5 indicating the intersections were congested. Signalised & unsignalised Intersection Design and Research Aid (SIDRA) software was further used to analyse the intersection to access the performance measure of the intersection. The result from the SIDRA software also confirmed that the intersection was congested. It was recommended that the capacity of the intersection should be increased; government should construct traffic signals and enforce law to sanction motorists that inappropriately park along the road sides close to intersection; appropriate government agency should carry out more public enlightenment on the use of traffic signal and other roads signs; and alternative roads should be constructed to mitigate the congestion at intersections. more...

For long-distance flying, drones often need to charge their battery at quick battery-charging machines (QCMs) because of their limited battery capacity. If a drone individually chooses a QCM without any coordination, a drone network may experience QCM congestion when multiple drones select the same QCM. This QCM congestion may lead to an increasing drone traffic delay. In order to solve this problem, we propose a cloud-based drone navigation (CBDN) system for efficient drone battery charging in drone networks. In order to achieve this goal, the CBDN gathers drone traffic information and determines efficient drone routes so as to minimize the overall QCM congestion level for drone battery charging using cloud-based management. Our key idea is to find globally coordinated drone routes so as to minimize the total traffic delay in a drone network by reducing the overall QCM congestion level. In order to demonstrate the effectiveness of the proposed system, we evaluated the performance of CBDN by simulating a drone network under various network conditions. The simulation results show that CBDN is more efficient than the existing shortest-path-based drone route planning algorithms in terms of end-to-end traffic delay and QCM average utilization. more...

Intermittent lane blockage at curb-side bus stops, characterized by aggressive lane changes, undue traffic delay and drop of road capacity, creates the major bottleneck in mixed urban traffic. This... more...

This article studies different analysis metrics of wireless networks using channel aware routing protocol. During communication the following characteristics are important performance metr...

The average is usually applied to describe the traffic delay, and the environmental factors are considered to influence it. However, the distribution and the influencing individual behavior on traf... more...

Traffic congestion is a major source of delays in modern road networks. Motivated by this, we propose two distributed algorithms to reduce delays: a dynamic lane reversal algorithm and a rerouting algorithm. When there is a density imbalance on a road, time can be saved by reallocating lanes from the less dense side to the more dense side, which motivates dynamic lane reversal. When a road has greater density than nearby roads, time can be saved by redirecting flow into the least congested roads, this motivates dynamic rerouting. Given a communication system between infrastructure and vehicles on the road, the local state of the network can be approximated and utilised by the algorithms to minimise travel time. In order to provide a better fundamental understanding of the system dynamics, we analyse equilibrium conditions for the system and prove convergence of the lane reversal algorithm to a critical point. Overall performance is also examined in simulation. more...

By decoupling control coverage and traffic coverage, dynamic base station (BS) sleeping becomes possible in hyper-cellular networks. Traffic coverage can be adjusted based on real-time demands, to enhance the energy efficiency of the networks. However, sleeping mechanisms may affect the networks delay performance. Thus, it is important to obtain analytical results on the influence of sleeping mechanisms on the systems energy efficiency and delay performance. The optimal sleeping mechanism can be derived based on the energy-delay tradeoff. This work summarizes the relevant contributions of our group: based on the vacation queueing model, closed-form expressions for average power and mean traffic delay were obtained. The conditions for the energy-delay tradeoff were analyzed. Further, the optimal BS sleeping design and the optimal energy-delay tradeoff were obtained, assuming fixed delays. The influence of the mode-changing energy cost was studied. BS sleeping designs for bursty traffic were analyzed, combined with power matching. The optimal BS sleeping mechanism for bursty traffic was obtained with a partially observable Markov decision process (POMDP). more...

Major cities in most of the developing countries are becoming increasingly crowded. Conventional open-trench methods are expensive and lead to traffic disruption. The domestic government is looking at alternative approaches to install and rehabilitate aging underground utilities. The purpose of this study is to investigate the level of awareness and utilization of no-dig (i.e., trenchless technology) methods, the potential of their future growth, and their impact on social costs in a developing country. A survey was first conducted to investigate the use of trenchless technology methods in new construction and rehabilitation of infrastructure projects. The pertaining impact on social costs was then examined. Survey data were analyzed, and the potential of future growth of using trenchless technology methods was investigated. It has been found that “horizontal directional drilling” is the prevalent trenchless method used, while “robotic spot repair” is the least utilized one among all the methods used for new construction or rehabilitation of underground utilities. The results also revealed that using trenchless construction has a maximum impact on the “travel/traffic delay” type of social costs. The “horizontal directional drilling” method has the highest potential of future growth in new construction, while the “lining of pipe” was ranked first among rehabilitation methods. The data analysis results have also revealed that a critical social implication of using trenchless construction methods is their limited disruptions to the society when installing or rehabilitating underground utilities. Such social disruptions include road closures, traffic delays, and detours resulting in noise and loss of access to homes/businesses. more...

This paper analyses the relevance of the traffic delay generated during the A-8 Spanish Motorway maintenance activities in order to make recommendations for inclusion within the LCA of roads. Six congestion scenarios combining the level of service of the Motorway and the alternative N-634 route have been evaluated using two software packages: KyUCP (macro-simulation) and Aimsun (micro-simulation), whose results have been transferred into emissions using MOVES. After performing the LCA considering a functional unit of a 1-km lane with an analysis period of 30 years, results show the huge importance of this stage in all the scenarios analysed. more...

Understanding the temporal and spatial dynamics of traffic accidents are a key determinant in their mitigation. This article leverages big data and a Poisson model with fixed effects to understand the causality of traffic congestion on road accidents in ten cities in Latin America: Bogota, Buenos Aires, Lima, Mexico City, Montevideo, Rio de Janeiro, San Salvador, Santiago, Santo Domingo, and Sao Paulo. Analyzing over 10 billion observations in 2019, results show a positive non-linear causality of congestion on the number of accidents. Overall, the results suggest that a 10% reduction in traffic delay would reduce accidents by 3.4%, equivalent to over 72 thousand traffic accidents. Sao Paulo and Mexico City would be particularly benefited, with reductions of 5.4% and 4.7%, respectively. The results of this paper aim to support policymakers in emerging economies in implementing measures to reduce congestion and, with it, the related direct and indirect costs borne by societies. more...

This paper presents a new class of models for predicting vehicle traffic delay in ferry terminals. Ferry service plays an important role in many cities adjacent to navigable bodies of water. Transp... more...

The concept of accessibility has made inroads into planning practice, largely at the system level. That is, accessibility is measured or modeled for current or future regional transportation and land-use scenarios for evaluation or broad policy guidance. Yet system-level scenarios cannot readily be applied to the project-by-project decision-making that characterizes the majority of transportation and land-use planning decisions. Accessibility evaluation of individual transportation or land-development projects differs from system-level analysis in essential ways and thus requires specialized tools. This article proposes an elasticity-based metric of accessibility that can enable project-level evaluation of land-development projects as an accessibility-based alternative to traffic-impact analysis. The metric is demonstrated for three projects in Ann Arbor, Michigan, USA. The metric is shown to be sensitive to the location of development and capable of distinguishing among the analyzed projects in accessibility terms. Where mobility-based evaluation tends to rank peripheral development highly, the proposed accessibility metric appropriately rates central development as contributing the most to regional accessibility even after accounting for the traffic delay it engenders. more...

This paper describes a suite of exercises that have been devised to help civil and structural engineering students develop a deeper understanding of the relevance of sustainable development to structural design. The exercises are based on a new tool called System for Appraising the Sustainability of Structures, which was designed to appraise the sustainability of bridge structures. Specifically, the exercises compare the sustainability of three alternative bridge designs for a motorway crossing, highlighting relevant performance indicators including climate change, resource use, noise, dust, vibration, aesthetics, cost of construction, cost of maintenance and traffic delay costs, together with methods for their evaluation both individually and in combination. The exercises primarily show that the choice of construction material and structural form can have a significant effect on the economy, society and environment and demonstrate the interconnectedness of the three themes. more...

Along with our country, a steady and rapid development of economy, politics and culture, the traffic also got rapid development with the trend. The improvement of people's living standard in our country, more and more frequent transportation also emerged, the requirement for the quality of travel people also put forward higher requirements; Therefore, as a responsible for the daily commuter traffic tools, urban rail transit train delay problem should give our attention. The types of urban rail traffic delay is described in this paper, including the initial delay and joint and several delays, and expounds the time characteristics and spatial characteristics of delays, and the urban rail transit delays was studied, on the single line shows the single delays the transmission of the recursive formula, for the delay of the urban rail transit emergency disposal provides theory basis. more...

A crossing is a meeting point between roads and railways, where this often causes delays and traffic queues, as happened at the crossing on Jl. Abimanyu, Tegal City. This study aimed to analyze the volume, delay and queue length of traffic on each road which occured due to the closing of the railroad crossing. Apart from that, this research was also intended to provide reasonable alternative input for both the management of Pertamina and the road users. This research used the analysis method of v/c ratio, queue and delay with reference to the Manual for Indonesian Road Capacity. Results of the analysis show, the highest queue occurred on the Abimanyu road, which was of 70.5 pcu with the delay of 581.5 seconds/pcu. On the segment of Jl. Menteri Supeno I, the traffic queue was reported to have reached 47.8 pcu with the delay time of 441 seconds/pcu; on the segment of Jl. Semeru, the queue was reported to reach 17 pcu with the delay of 395.6 seconds/pcu, and the last one was the queue at the segment of Jl. Menteri Supeno II which was of 10.8 pcu, with the delay time of 368.5 seconds/pcu. Ones of the keys to overcome problems of traffic queues and delay were by dividing the shunting time into 2 phases according to the results of alternative analysis II where the traffic queue became smaller of 35.3 pcu with the delay time of 290 seconds/pcu and by changing the shunting schedule at off peak time. more...

In urban transportation, scheduling algorithms in traffic signal control (TSC) are important for achieving high throughput and low latency traffic flow, lowering accidents, and reducing emissions. As new scheduling algorithms are being developed particularly to leverage and accommodate connected and autonomous vehicles, there is increased potential for cyber-attacks on TSC that can undermine the benefits of new algorithms. Attackers can learn the behavior of scheduling algorithms and launch attacks to get scheduling priority and/or to create traffic panic and congestion. These attacks can compromise the system and significantly increase traffic delay and make TSC completely ineffective. In this paper, we compare the performance of different backpressure-based scheduling algorithms when they are under attack. We consider four different backpressure-based schemes, namely, delay-based, queue-based, sum-of-delay-based, and hybrid scheme that combines delay-based and queue-based schemes. We consider time spoofing attacks where individual vehicles arriving at an intersection can alter their arrival times. Through detailed simulation analysis we show that while the delay-based scheme has better fairness performance, it is more vulnerable to time spoofing attacks than the other schemes. We explore drawbacks of the delay-based scheme under different scenarios including non-homogeneous arrivals both for isolated intersection as well as multiple intersections. This study throws light on how to prevent time spoofing attacks on next generation TSC. more...

In order to improve the aerospace network transmission performance considering the limitation of hardware resources and power consumption, a dynamic bandwidth scheduling method is proposed for burst traffic in FC-AE-1553 switching network. The feasibility of this scheduling mechanism is analyzed from the perspective of network throughput and burst traffic average delay based on simulation results. more...

Signal synchronization is an important countermeasure to improve efficiency and relieve congestion for urban arterials. Scientifically evaluating the effects is the foundation for signal synchronization optimization. A signal synchronization evaluation and optimization model is proposed based on delay and queue length assessment at arterial intersections. With traffic wave theory, taking intersections’ phase and sequence, split, movement, link length and offset into considerations, the model can simulate the evolution of queue endpoint phase by phase, and get a polygon which can be used to calculate the control delay. The case study indicated that the model can accurately designate the influence of variable signal coordination parameters, and can be used to arterial signal synchronization appraisal and optimization. more...

Ethernet TSN is an upcoming communication standard for industrial distributed embedded systems with high demands on bandwidth and traffic delay. In this paper, we present and prove an improved analysis to determine bandwidth reservations for credit based shapers in a single Ethernet TSN switch. We compare this new analysis, which is based on eligible intervals, to the state-of-the-art bandwidth reservation analysis based on busy periods through experiments. Despite its low complexity and the independence of the knowledge of the interfering traffic, the results show an improvement of efficiency, i.e., a decrease of the required bandwidth, for the new analysis. more...

Travel speed estimation at the city level is the essential problem advantageous to many forms of urban transport applications. This paper proposes a travel speed estimation of road network from the GPS data of public transportation system by analyzing trajectory data using machine learning techniques and simple linear and non-linear equations. Map matching algorithms and KNN model are used to project trajectory on to the map and to determine the start and end points of road segments, respectively. The average travel speed of every road segments along the bus route are estimated by using historical data and live GPS data of running buses. Features related to traffic delay are extracted from the Place of Interest (POI) near the road segment. The speed factor matrix is generated based on the output of Travel Speed Estimation Model and traffic delay related features. more...

Improper mandatory lane change (MLC) maneuvers in the vicinity of highway off-ramp will jeopardize traffic efficiency and safety. Providing an advance warning for lane change necessity is one of the efficient methods to perform systematic lane change management, which encourages smooth MLC maneuvers occurring at proper locations to mitigate the negative effects of MLC maneuvers on traffic flow nearby off-ramp. However, the state of the art indicates the lack of rigorous methods to optimally locate this advance warning so that the maximum benefit can be obtained. This research is motivated to address this gap. Specifically, the proposed approach considers that the area downstream of the advance warning includes two zones: (i) the green zone whose traffic ensures safe and smooth lane changes without speed deceleration (S-MLC); the start point of the green zone corresponding to the location of the advance warning; (ii) the yellow zone whose traffic leads to rush lane change maneuvers with speed deceleration (D-MLC). An optimization model is proposed to search for the optimal green and yellow zones. Traffic flow theory such as Greenshield model and shock wave analysis are used to analyze the impacts of the S-MLC and D-MLC maneuvers on the traffic delay. A grid search algorithm is applied to solve the optimization model. Numerical experiments conducted on the simulation model developed in Paramics 6.9.3 indicate that the proposed optimization model can identify the optimal location to set the advance MLC warning nearby an off-ramp so that the traffic delay resulting from lane change maneuvers is minimized, and the corresponding capacity drop and traffic oscillation can be efficiently mitigated. Moreover, the experiments validated the consistency of the green and yellow zones obtained in the simulation traffic flow and from the optimization model for a given optimally located MLC advance warning under various traffic regimes. The proposed approach can be implemented by roadside mobile warning facility or on-board GPS for human-driven vehicles, or embedded into lane change aid systems to serve connected and automated vehicles. Thus it will greatly contribute to both literature and engineering practice in lane change management. more...

Signal control of urban, intersections still mainly employs single-point fixed phase, and optimal timing methods cannot optimize traffic given the altering state of traffic flow. To address these issues, the phase of optimal flow line combination is dynamically generated with the principle of traffic flow line compatibility and minimum loss of green light and according to the traffic flow at the intersection entrance. After ascertaining the combination of the periodic phase, the vehicles’ average delay of traffic flow lines is analyzed when the vehicles are detained (or not detained) in the traffic flow line at the end of the period. Combined with the delay model, the optimal timing model, which can adapt to the dynamic changes in intersection traffic flow, is established. The optimal timing of phases is calculated to achieve dynamic optimization control of the intersection traffic line. The calculation example shows that the delay is small and the improvement of intersection running state is highly effective when the optimal timing model based on dynamic control of traffic flow is employed. more...

This paper proposes a dynamic lane assignment (DLA) approach for one-sided freeway weaving segments. The approach divides the weaving segment into weaving lanes and nonweaving lanes to reduce the disturbance between weaving and nonweaving traffic streams. The proposed DLA strategy is optimized by nonlinear integer programming under various on-ramp traffic volumes and weaving volume ratios. The applicability of DLA is tested with numerical experiments under different weave types, traffic flow rates, weaving volume ratios, and segment lengths. A VISSIM microsimulation model was developed and used to evaluate the performance of the proposed strategy. Test results drawn from the numerical experiments and simulation indicate that the proposed DLA approach is applicable when the main-line weaving volume ratio is relatively low and it can increase the capacity and decrease the traffic delay for the weaving and upstream segments. more...

Analyzing the influence on traffic flow at intersection according to the driving characteristics of modern tram with different lane layout types. Proposing a method of dynamic priority algorithm (DPA) based on the idea of multiple attribute decision making (MADM) to analyze intersection delay. The VAP module based on MATLAB in Vissim is used to simulate the induction control of the modern tram through the concrete intersection, mainly analyzing delay of the intersection with different lane layout types of modern trams. Taking the intersection of Middle Jiangdong Road and Hexi Avenue in Nanjing as an example, the traffic delay caused by different lane layout of modern tram is analyzed by using absolute priority and dynamic priority algorithm (DPA) respectively. more...

In this paper, we develop a mathematical decision model and a solution algorithm to prioritize and schedule work zones in the planning process. The model is designed to measure the mutually interacting traffic impact and delay as a result of work-zone disruptions in the network. Several construction strategies that interest stakeholders are discussed, including daytime and nighttime construction modes, sequencing precedence, and the seasonal variation effect of demand. The method evaluates networkwide traffic delay through a $k$-shortest path algorithm to analyze drivers' behavior of alternative-route selection. A numerical example is analyzed on a real-world network to demonstrate the applicability of the model for a road construction scheduling problem. more...

Intersection is the bottleneck of city traffic and the major contributing factor to traffic delay, which has a great impact on path selection. This paper first analyzes and models the turning characteristic at typical intersections, then discusses the analysis result of typical intersections in Wuhan city based on floating car data, and finally verifies the influence of intersection turning characteristic on path selection and optimization. more...

Traffic congestion is a major concern for many cities throughout the world. Developing a sophisticated traffic monitoring and control system would result in an effective solution to this problem. In order to reduce traffic delay, a novel urban arterial traffic signal coordinated control method is presented. The total delay of downstream and upstream vehicles is considered and the function describing the relationship between vehicles delay and signal offset among intersections is established. Finally, comparing the performance of traffic signal under method proposed in this paper with the traditional isolated traffic signal control method, the microscopic simulation results show that the method proposed in this paper has better performance in the aspect of reducing the vehicles delay. The offset model is tested in a simulation environment consisting of a core area of three intersections. It can be concluded that the proposed method is much more effective in relieving oversaturation in a network than the isolated intersection control strategy. more...

The requirement to build durable, sustainable and low-maintenance airfield infrastructures has become more important in recent years due to the expected air traffic increase and its impact on the environment. The high customer expectation of infrastructure availability and minimum traffic delay during maintenance has also become significant. This paper introduces French asphalt mix design methods for use in airfield pavement construction as an alternative to conventional UK materials, to offer improved performance and better whole-life cost solution. A case study at Sumburgh Airport in the Shetland Islands, UK is presented. more...

This paper discusses an approach to life-cycle assessment (LCA) for pavement construction applications. The scope of the study included the material production and construction phases pertaining to the upper layers of pavement; the aim was to quantify energy consumption and greenhouse gases. Life-cycle inventory data were taken from literature sources and questionnaires, with system boundaries including upstream processes for the production of major materials and fuels. The use of regionalized data was necessary to ensure proper application of LCA. Thus, for the material production phase, this LCA included preliminary data collected from regional surveys and incorporated a localized life-cycle model for asphalt binder production. The impact of traffic delay was modeled in the construction phase with the U.S. Environmental Protection Agency's Motor Vehicle Emission Simulator. A case study was performed for a simulated two-lane reconstruction of an existing Interstate in northern Illinois. The energy consumption in the material phase [5,425 million (M) Btu/lane mile] was significantly higher than that of the construction phase (137 MBtu). The same pattern held for global warming potential [405 versus 12.0 tons of carbon dioxide equivalent (CO2e)]. With respect to traffic delay, the values of global warming potential (between 2.0 and 9.9 tons of CO2e) and energy consumption (between 22.5 and 116.8 MBtu) were comparable to those from the construction phase. more...

This study attempted to develop a control strategy in order to minimize the traffic delay caused by the traffic incident. The proposed strategy controls traffic in terms of providing a combination of different types of incident information. We used the cell transmission model as the underlying traffic flow model to take into accounts the traffic dynamic and use the simulated annealing algorithm to seek the optimal combination of the incident information. The numerical examples confirmed that providing incident information through the proposed control strategy can significantly reduce the traffic delay. more...

In order to improve the running safety of highway, to minimize traffic delay, and to avoid the secondary traffic accident, it is essential to evaluate the operating efficiency of the highway network under accident conditions. This article selects the time reliability as evaluation index and compares the index value of the highway network under normal, accident conditions and after emergency traffic organizations. Differences are used to perform an analysis on the impact on traffic of the accident, the result of the emergency traffic organization and the recovery degree of the transport. The paper provides some basis for the traffic organization plan optimization of the road network under the accident conditions. more...

This paper presents a review of the approaches to estimating the work zone operational issues: capacity and traffic delay in work zones. It first explores the factors affecting work zone capacity and then critically reviews three types of approaches including parametric, non-parametric and simulation approaches to estimating work zone capacity. Subsequently, a detailed critical review of the three types of approaches for traffic delay estimation in work zones is presented. Finally, it provides some directions and recommendations for the future research. more...

This paper analyzes driver behavior when alerted to the impending end of green while they travel on high-speed signalized intersection approaches that are equipped with actuated advance warning (AAW) systems. These systems are widely deployed in Nebraska and provide a more than 90% likelihood of improving safety. They consist of one detector placed in advance of the intersection and active warning signs with the legend, “prepare to stop when flashing.” The overall goal is to reduce, if not eliminate, the number of drivers who are caught in the dilemma zone. A nonintrusive mobile data collection system was used to monitor traffic and collect a continuous stream of traffic data up to 304.8 m (1,000 ft) upstream of the stop line on two high-speed signalized intersection approaches that were equipped with AAW systems. The results indicate that the system is effective at alerting drivers to the impending end of the green light; approximately 78% of the drivers observed in this study either maintained t... more...

As an important urban transportation mode, urban rail transit (URT) systems act as a key solution for high-density passengers. For the URT systems, even minor disruptions of can lead to severe harm of passenger safety, large traffic delay and widespread confusion because of the passenger density. In emergency circumstances, quick response and efficient substitution services like bus birding is of great importance for evacuation and accommodation of the affected passengers. In this paper, we propose a mathematical programming with indicator constraints model for designing a responsive bus bridging services under URT line emergency. The response time is integrated as an objective in the problem by considering the distance between the bus parking spots and the URT station as a starting point of a scheduled line. To solve the proposed model, a Genetic Algorithm (GA) based procedure is deployed because of the intractability. The results of some numerical experiments are also provided to demonstrate the proposed model. more...

Highway work zones often cause traffic congestion, resulting in increased road-user delays and vehicle emissions. These negative impacts of highway work zones can be minimized by a number of mitigating measures such as reducing the length of work zone segments, using the shoulder temporarily for traffic, and working during low-traffic nighttime hours. These work zone layout measures, however, cause an increase in highway construction cost. Accordingly, these tradeoffs between reducing work zone delays and minimizing construction cost need to be analyzed to establish an optimal balance between these two critical and conflicting objectives. This paper presents the development of a novel multiobjective optimization model for highway work zone layouts that is capable of generating optimal tradeoffs between minimizing traffic delays and construction cost. The model was developed in three main phases: formulation, implementation, and performance evaluation. First, the model was formulated to (1) identif... more...

An e-bicycle, also known as an electric bicycle, is one of the major trip modes in the third and fourth-tier small cities of China which is quite different from big cities such as Beijing and Shanghai. Traditional traffic signal control approaches are often based on the pure motor vehicles, regardless the effect of increasing e-bicycles. This paper proposed a discharge model of e-bicycle mixed traffic flows and developed an average delay formula based on that. We analysed the relationship between the average delay and cycle length, for the cases of pure motor vehicles delay and e-bicycle mixed traffic delay, respectively. Moreover, we presented a practical traffic signal control strategy for intersections with e-bicycle mixed traffic flow. It demonstrates that the optimal cycle length obtained from the proposed method is normally larger than that got from the Webster method, which complies with the field application and fits the real traffic circumstances. more...

This paper presents a quantitative analysis model of curb parking impacts on traffic flow delay. Whether a road is appropriate setting curb parking is quantitatively analyzed. Based on the variation of traffic delay on a road with curb parking lots, the impacts of curb parking facilities on traffic flow are analyzed. The traffic delay caused by curb parking activities that under both low and high volume conditions are researched. A model respectively using discrete, continuous values of delay as evaluation indicator is built. The validity of the model is tested through application examples. more...

To share the lanes with conventional vehicles, traffic operation strategy is needed for NEV (Neighborhood Electric Vehicle). Because NEV cannot accelerate sharply as fast as common car include gasoline, diesel and LPG cars, they may interrupt traffic conditions and make traffic delay. After green lights turn on, all vehicles run through the street including NEV, but NEV have a maximum speed which is 50km/h. It can be an obstacle for following vehicles and will make traffic delay of the intersection. In this reason, we need to organize traffic systems like queue jump with priority traffic signal. To analyze the necessity for NEV road operations, we simulate three scenarios in congested and non-congested conditions. First is that we examine the condition which is mixed NEV and cars on the road, the second one is that we set up lane only NEV can accepted in simulation and last one is making queue jump lane and providing priority signal for NEV. In conclusion, we can conclude that making lane only for NEV is effective to improve travel speed when rate of NEVs is over 20%. Also queue jump lane and priority signal cannot make good effect to intersection delay and average speed. more...

An integrated corridor control system is proposed to manage traffic dynamically between the mainline freeway and the diversion route in real time. The system's objective is to alleviate the total corridor delay attributable to nonrecurrent or recurrent congestion on the freeway. An optimization-based model, the integrated corridor traffic optimization model (ICTOM), was established to minimize total traffic delay, including delays on the freeway, signal control delays on the diversion route, and delays attributable to travel time differences between two routes. The model determines diversion volumes from the freeway to an arterial corridor and signal-timing plans on the diversion route. ICTOM features a nonlinear objective function and linear constraints. Three algorithms were evaluated in seeking a solution for ICTOM: genetic algorithm, pattern search, and sequential quadratic programming. The sequential quadratic programming algorithm was selected because of its effectiveness and efficiency in the case study. Evaluation based on the CORSIM simulation showed that in real time, ICTOM realized total average reductions in corridor delay of 8.77%, 9.92%, and 13.16% under heavy-, moderate-, and light-traffic conditions, respectively, compared with the benchmark in which the timing plans for traffic signals were optimized by TRANSYT 7F offline. more...

Transition taper length plays a vitally important role in work zone safety operations because too short a transition taper length will result in higher accident risks and too long a transition taper length could increase traffic delay. This paper evaluates transition taper length under various traffic conditions and road geometries using collision avoidance analysis. The longitudinal distances for lane changing and emergency stopping manoeuvres are respectively calculated using collision avoidance analysis. The higher value between the longitudinal lane changing distance and emergency stopping distance is considered as the expected transition taper length. The comparison of transition taper lengths from the collision avoidance analysis and current empirical transition taper formulae shows that the collision avoidance analysis has the capability of evaluating transition taper lengths. This paper also contributes to providing theoretical supports for these empirical formulae. more...

As life-cycle assessment (LCA) increasingly is used to evaluate the environmental footprint of pavements, there is growing need to critique the state and utility of the supporting science. LCA is a data-intensive methodology that requires inputs and models from a variety of different scientific fields. While some data sources are mature, others are products of nascent and inexact research. Within pavement LCAs, traffic delay, rolling resistance, concrete carbonation, pavement albedo, lighting, leachate, and end of life allocation are areas where the supporting science is incomplete or is ineffectively incorporated into the pavement LCA framework. These components produce quantitative gaps in the assessment methodology, thus jeopardizing the accuracy of results and defensibility of conclusions. Benchmarking where the science stands allows practitioners to perform LCAs while incorporating the best available information, including best estimates and gross evaluations of the uncertainty. Moreover, identifying weaknesses in the fields that support pavement LCAs provides a transparent assessment framework and generates a focused research direction moving forward. more...

In this paper, based on survey data of delays on intersections in urban highways and in accordance with theoretical capacity of each traffic lane, various reasons of delay in intersections are analyzed numerically. A discrete traffic model to simulate traffic in intersections using Gaussian mesh method is built. After modifying intersection properties, weight of each factor in terms of their effect to capacity is acquired. An optimized way to solve traffic delay is hereby recommended. more...

Although ultimately bringing long term economic benefit, highway construction activities temporarily increase highway user costs and non-user costs, and affect highway safety and the environment. In order to minimize the negative effects of construction projects, state highway agencies have been using incentive/disincentive clauses in contracts to reward contractors for early completion of projects, and to recover the engineering and administrative costs incurred when contractors miss completion deadlines. Evaluation of excess user costs of traffic delays caused by the presence of work zones is essential for assessment of the impact of the work zones on the public. The estimated user costs provide highway engineers and construction managers with useful information for effective highway construction planning. For any highway construction project, there exists a construction time that would minimize the construction cost with given manpower and equipment. If the project is shortened or prolonged from this c... more...

Many different types of construction projects set up work zones on roads. Especially in urban areas, lane closures as a result of work zones have a considerable impact on local traffic. However, for a construction project that consists of several work zones and several work crews, the traffic impact may be improved by appropriate scheduling. Therefore, this paper proposed a scheduling model based on the route-changing behavior of road users. The proposed model calculates the traffic delay of vehicles by microscopic simulation, and applies team ant colony optimization to search for a near-optimal schedule. The project planner then ensures that the contractor executes the activities according to the near-optimal schedule. The proposed model is applied to schedule a sewer system construction project in a city. The results of our study indicate that with our proposed model the total traffic delay is reduced by 11.1% when compared with a schedule proposed by the project planner. more...

Consideration of the excess user costs of traffic delays caused by the presence of work zones is essential for assessment of impact of the work zones on the public. The excess user costs include traffic delay costs and additional vehicle operating costs resulting from speed changes at work zones. User costs at highway work zones are increasingly used by highway agencies to determine the contract times of highway construction projects. This paper analyzes the user costs at freeway work zones based on traffic data recorded by weigh-in-motion devices in Indiana. With a high traffic volume, user costs caused by a work zone can be significant; it is therefore desirable to minimize the user costs by expediting construction process. User costs at work zones are often used as the basis of determination of the monetary values for incentive or disincentive clauses in highway contracts for early or late completions of highway construction projects. In this study, the user costs at freeway work zones were computed ba... more...

This paper presents a decision support tool that is intended to help highway agencies in evaluating the suitability of nighttime construction for highway projects. This tool was developed as part of a research project sponsored by the Illinois Department of Transportation. The tool is a simple software package that was developed using a Microsoft Excel spreadsheet and Visual Basic for Applications. The proposed tool utilizes the cost-effectiveness analysis as a basis for comparison between daytime and nighttime operations. The proposed tool is mainly used whenever night shift is thought of as an alternative to the conventional daytime shift. Nonetheless, the tool is also generic in the sense that it can be used to compare different alternative plans such as different lane closure strategies or scheduling alternatives. more...