2013 Session: 541

• Dynamic Programming Approach for Arterial Signal Optimization
  Abstract: Link Performance Functions (LPFs) are essential components of macroscopic models for signal optimization, traffic assignment or combined control-assignment models. Numerous studies have developed a variety of performance functions for signal optimization. Most of these studies attempted to use simplified LPFs that do not capture the important relationships and dependencies among the variables. In this paper we introduce dependent link performance functions (DLPF), where the performance on any link depends not only on the flow pattern on that link alone, but also on the flow patterns on the feeder links. Such functions represent with greater fidelity the performance characteristics of the link and can lead to better control, assignment, etc. We then present an optimization model that explicitly considers flow interactions among successive links and applies it in a dynamic programming procedure to determine optimal signal settings. The procedure is an offshoot of the Combination Method for offset optimization. The procedure is illustrated for an arterial street and demonstrates its efficacy in comparison with existing optimization models.
  Authors: Gartner, Nathan H.; Deshpande, Rahul
  Authors: Gartner, Nathan H.; Deshpande, Rahul
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-0177
• Traffic Signal Timing Optimization: Choosing the Objective Function
  Abstract: Choosing an appropriate objective function in optimizing traffic signals in urban transportation network is not a simple and straightforward task because it most likely would affect the set of constraints, modeling variables, outputs obtained, and computer and human resources needed. In this study we develop a methodology for selecting the appropriate objective function for the signal timing optimization problem, and apply it to a realistic case study network under four different demand patterns (symmetric/asymmetric undersaturated/oversaturated). The selection is made from five candidates: delay minimization, travel time minimization, throughput-minus-queue maximization, maximizing the number of completed trips (or trip maximization), and maximizing the weighted number of completed trips (or weighted trip maximization). Findings indicated that for all demand patterns, weighted trip maximization improved network performance compared to the other objective functions. It reduced system total delay by 0.1% to 5.2% in symmetric undersaturated demand, by 1.0% to 2.4% in asymmetric undersaturated demand, by 1.2% to 16.6% in symmetric oversaturated demand, and by 11.7% to 27.4% in asymmetric partially oversaturated demand. These figures indicate that the weighted trip maximization objective function is most suitable among the candidate for oversaturated conditions especially when demand is not symmetric. Throughput-minus-queue and trips maximization objective functions were the second most suitable objective functions for oversaturated conditions where trip maximization was slightly more suitable when demand was asymmetric.
  Authors: Hajbabaie, Ali; Benekohal, Rahim F.
  Authors: Hajbabaie, Ali; Benekohal, Rahim F.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-0261
• SURTRAC: Scalable Urban Traffic Control
  Abstract: This paper defines and evaluates a pilot implementation of a recently developed approach to real-time, adaptive traffic signal control. The pilot system, which is called SURTRAC (Scalable Urban Traffic Control), integrates concepts from traffic control theory with recent work in the field of multi-agent planning and has several important distinguishing characteristics. First, to promote scalability and reliability, SURTRAC operates in a totally decentralized manner; each intersection independently and asynchronously allocates its green time, based on current incoming vehicle flows. Second, SURTRAC aims at managing urban (grid-like) road networks with multiple (competing) traffic flows; network-level coordination is accomplished by communicating projected outflows to downstream neighbors, which gives these intersections a more informed basis for locally balancing competing inflows while simultaneously promoting establishment of larger "green corridors". Third, SURTRAC truly operates in real-time; each intersection recomputes its allocation plan and re-communicates projected outflows every 1-2 seconds in rolling horizon fashion, enabling both effective operation in tightly spaced signal networks and responsiveness to sudden changes in traffic conditions. After describing our basic approach to adaptive traffic signal control and the pilot implementation of SURTRAC, we present the results of a field test conducted on a nine-intersection road network in the East Liberty section of Pittsburgh, Pennsylvania. In this pilot test, SURTRAC is seen to achieve major reductions in travel times and vehicle emissions over pre-existing signal control.
  Authors: Smith, Stephen F.; Barlow, Gregory J.; Xie, Xiao-Feng; Rubinstein, Zachary B.
  Authors: Smith, Stephen F.; Barlow, Gregory J.; Xie, Xiao-Feng; Rubinstein, Zachary B.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-0315
• Performance Assessment on Noncoordinated Signalized Arterials and Guidelines for Signal Coordination
  Abstract: This paper introduces a probabilistic model for calculating the expected number of stops on non-coordinated arterials. The model can be applied to developing a practical guideline for determining when the signals in an arterial should be coordinated. The main assumption of the model is that the probability of making a stop is a function of the effective green to the cycle length ratio which also relates to the traffic volume and capacity. Various sources made recommendations in terms of the traffic volume, platoon dispersion, and signal spacing, concerning when a coordination plan should be implemented. However, none of them considered the number of stops as a factor. We propose a stop-based guideline using the probabilistic model, stating that an arterial should be coordinated if the number of stops exceeds 50%. An arterial does not need to be coordinated when the number of stops falls below 20%, and engineering judgment should apply between these two thresholds. A case study using a VISSIM simulation was conducted to validate the probabilistic model and the proposed guideline in order to test its practicality. The results confirmed that the probabilistic model is highly reliable in estimating the number of stops, thus the developed guideline proved to be practical in considering both the main street and side street performances.
  Authors: Andalibian, Rasool; Zong, Tian Z.; Wu, Ning; Farivar, Saeedeh
  Authors: Andalibian, Rasool; Zong, Tian Z.; Wu, Ning; Farivar, Saeedeh
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-2258
• A Coordinated Optimization Model for Signal Timings of Full Continuous Flow Intersection
  Abstract: Continuous flow intersection was invented by Francisco Mier to improve traffic operation in the intersection that suffers from traffic problems caused by heavy left-turn movement. Although it has developed for 25 years, some real intersections have been built and have achieved good results, there is no general model of signal timings and offsets for it. This paper (1) puts forward the main relationships that are needed to deal with in CFI model, then (2) builds a detailed model for optimization of phase sequence scheme, length of cycle, durations of each phase, and offsets between successive signals. (3) Comparison of the computing results of minimum cycle, capacity and average delay of CFI with conventional intersection. The results show that CFI has a clear advantage and this model has a wide range of application. The proposed model and algorithm also have the following two features: (1) location of the sub intersection as a design parameter need not be inputted but is affected by offset and queue length, (2) solving process and algorithms of all critical features such as average delay are provided. Because of simplified solving process, the computation is not enormous with the help of a simple procedure running on PC, so this model is easy for application.Keywords: continuous flow intersection; model for signal timings; queue length; average delay; evaluation.
  Authors: You, Xiaoming; Li, Li; Ma, Wanjing
  Authors: You, Xiaoming; Li, Li; Ma, Wanjing
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-2643
• Quantifying and Comparing Left-Turn Strategy Performance
  Abstract: Intersection performance is often impacted and even limited by the need to serve left turn movements. Left turns may be served in a number of ways, varying from permitted left turns to flashing yellow left turn arrow to protected left turns. Each method may be employed in a number of different strategies. For example, protected left turns may be employed in leading left turns, leading and lagging left turns, conditional left turn phase reservice, and fixed left turn phase reservice.To give practitioners and researchers more insight into left turn operations, this research implements a number of different left turn strategies under varying volume, volume differential and turning conditions while measuring the delay and queue lengths associated with each left turn strategy. The following findings are discussed in this paper. First, at low volumes, permitted only phasing offers the best performance. Second, protective-permitted phasing, including leading left turn with green ball, Leading left turn with Flashing Yellow Arrow (FYA), and FYA followed by lagging lefts, performs better as volume differentials increase as well as when turning rates increase. Phase reservice on left turn phases has a definite impact on queue length and delay experienced by the left turn phase, though it is also likely to be accompanied by a decrease in performance elsewhere in the intersection.
  Authors: Corey, Jonathan; Lao, Yunteng; Wang, Yinhai
  Authors: Corey, Jonathan; Lao, Yunteng; Wang, Yinhai
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-2868
• Coordinated Optimization of Signal Timings for Intersection Approach with Pre-signals
  Abstract: Many congested intersections have heavy traffic volumes on movements where there is insufficient capacity due to geometric limitations. Installing pre-signals at midblock locations and reorganizing traffic upstream approach of an intersection is a promising and cost-effective method to address these capacity limitations. This paper focuses on developing and evaluating a coordinated optimization model for an isolated intersection approach with pre-signals to increase protected left turn phase capacity. The pre-signal model is based on two principles: (1) Explicitly capturing the interaction between the pre-signal signal and the main-signal by modeling the queuing process and capacity constraints of temporal and spatial limitations of the intersection; and (2) Optimizing the signal timings of both the pre-signal and the main-signal as well as the offset between them to produce the best operational strategy for the approach. The minimum green time required and the delay minimization problems are considered. Extensive experimental analysis has shown that the pre-signal model outperforms the conventional control method (without pre-signal). Sensitivity analysis of the signal timing method was also conducted to assist traffic engineers with selecting the appropriate length of the sorting area, phase sequence and early starting time of pre-signals. The results from this study offer a basis for traffic practitioners, researchers, and authorities to design and utilize pre-signals in situations where there is a need to increase intersection capacity for congested movements.
  Authors: Ma, Wanjing; Xie, Hanzhou; Liu, Yue; Head, Larry; Luo, Zhenke
  Authors: Ma, Wanjing; Xie, Hanzhou; Liu, Yue; Head, Larry; Luo, Zhenke
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-3033
• Research on Dynamic Signal Control for Exclusive Right-Turn Lane at Mixed Traffic Flow Intersections
  Abstract: Traffic conflicts among right turn vehicle (RTV), non-motorized vehicle (NMV) and pedestrian were examined for urban signalized intersections with exclusive right turn lane. This study proposed an approach to dynamically calculating the duration of the prohibited right turn for vehicles by using a measure we call the Degree of Clustered Conflict, (DCC). The process of DCC control includes: 1) quantitatively calculating DCC value in conflict area; 2) establishing the general cost model that combines delay and conflict indicators; and 3) applying the DCC-control time model to control right turn vehicle in real time. Based on these, the paper presented a general approach of detailed dynamic on-line signal control process of RTV. Finally, the RTV control process was programmed based on VISSIM simulation to evaluate the control effectiveness. The results showed that the general cost (weighted summation of delay and conflict) of the RTV control decreases rapidly compared with non-control, fixed control and full control (drop 58%, 35% and 42% under small flow conditions and 70%, 59% and 17% in the large flow conditions, respectively). The method not only improved the operation efficiency, but also reduced the conflicts among traffic participants when vehicles turn right at intersections.
  Authors: Sun, Jian; Zhao, Li; zhang, Yancong; Wu, Zhizhou
  Authors: Sun, Jian; Zhao, Li; zhang, Yancong; Wu, Zhizhou
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-3206
• Self-Organizing Control Logic for Oversaturated Arterials
  Abstract: Decentralized, actuated traffic signal control has many advantages, but lacks mechanisms for coordinating with other signals along an arterial. When an intersection along an arterial is near or over saturation, coordination can play an important role in preserving and utilizing capacity by preventing spillback and starvation. In this paper, rules that can be added to a base of decentralized, clock-free actuated control are proposed for managing queues during periods of oversaturation. They are part of a larger framework for developing logic that will make arterial traffic signals self-organizing, rather than organized around a common signal cycle. Features of the proposed logic include green truncation in case of intersection spillback, early green and double realization for left turn phases prone to pocket spillback due to a limited turn bay length, and dynamic coordination for groups of signals spaced too closely together to hold a normal cycle’s queue. With dynamic coordination, green waves are scheduled each cycle following the critical intersection’s critical arterial through phase, with non-critical intersections adjusting offsets based on queue counts and a logic that allows temporary spillback at upstream intersections in order to prevent starvation at the critical intersection, and temporary starvation at downstream intersections in order to prevent spillback at the critical intersection. Simulation tests using a benchmark network shows performance far superior to standard coordinated control, and slightly better than an optimizing control method designed for oversaturated arterials. Simulation tests on two realistic networks also show positive results compared to coordinated control.  
  Authors: Cesme, Burak; Furth, Peter G.
  Authors: Cesme, Burak; Furth, Peter G.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-3218
• Evaluation of Microwave Radar Vehicle Detectors at Signalized Intersection Under Adverse Weather Conditions
  Abstract: Two microwave-based systems for vehicle detection, manufactured by Wavetronix and MS SEDCO, were evaluated at stop bar and advance zones of a signalized intersection under three adverse weather conditions: 1) high wind speeds, 2) rain, and 3) fully/partially snow-covered roadway. Data under normal (favorable) weather was also analyzed and used for comparison. Results show that the performance of the two systems deteriorated during adverse weather, and the type of detection errors and their frequency were system-dependent. In general, wind increased false calls at the advance detection zone by more than 50%, depending on the location and sensor type; snow-covered roadway had more widespread effects and increased false calls at stop bar and advance zones, depending on the system, and also increased missed calls at stop bar zones; and lastly, rain also affected the two systems by increasing false calls and stuck-on calls at the stop bar, and false calls at the advance zones. Data also shows that frequencies of false and missed calls were likely to increase as the precipitation intensity and wind speeds increased. Results from this evaluation show significant effects of adverse weather on microwave detection systems, and provide valuable information to researchers and practitioners regarding performance of similar setups under such conditions. Details on the detection errors offer insight on potential situations that should be monitored in practice and could also be used to improve performance under adverse weather.
  Authors: Medina, Juan C.; Ramezani, Hani; Benekohal, Rahim F.
  Authors: Medina, Juan C.; Ramezani, Hani; Benekohal, Rahim F.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-3394
• Multiregime Adaptive Signal Control for Congested Urban Roadway Networks
  Abstract: A hierarchical adaptive signal control is developed and implemented in New York City to manage congestion in a complex urban roadway environment. A set of control strategies, ranging from strategically regulating traffic demand to balancing queue-storage ratio at critical intersections, work in concert to systematically alleviate congestion and improve mobility. Due to the high usage of ETC tags in this area, large scale per-trip travel time data are collected (nearly 1 million per-trip travel time records daily), and utilized in real-time for effective control. Congestion levels are mapped to different control regimes. Various demand regulating strategies, depending on the prevailing congestion levels are applied at the peripheral roadways of the target control zone. These strategies proactively employ signal offsets and splits to exert a tapering and rebalancing effect on the traffic, for the purpose of better utilizing available network storage spaces while preserving the capacity of the target control zone. Inside the target control area, a dynamic queue balancing strategy is implemented at selected critical intersections to prevent propagation of spillovers with stabilized or diminished queues. The initial implementation covers 110 intersections in a highly congested central business district of Midtown Manhattan. Results to date are summarized.
  Authors: Xin, Wuping; Chang, Jinil; Muthuswamy, Satya; Talas, Mohamad A.; Prassas, Elena S.
  Authors: Xin, Wuping; Chang, Jinil; Muthuswamy, Satya; Talas, Mohamad A.; Prassas, Elena S.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-4154
• Effects of Metered Entry Volume on an Oversaturated Network with Dynamic Signal Timing
  Abstract: This paper analyzes the effects of different metering levels at the entry points of a simulated network to maintain traffic conditions that allow for efficient vehicle processing inside the network. Metering signals were placed in advance of the network entry points to limit the number of vehicles arriving to intersections along the perimeter and prevent oversaturation. In the simulation environment, traffic signals were externally controlled in a cycle-free mode by independent agents using a learning algorithm based on approximate dynamic programming (ADP). Agents reacted in real time to current demands and occupancy estimated from entry and exit detectors located in all links. Metering strategies were investigated in terms of delay, throughput, network congestion, and queue management. Results indicate that metering did have a significant effect on the measures of performance. Metering to levels just below the maximum throughput capacity of an isolated intersection resulted in increased network throughput (up to 5%) and reduced the delay of vehicles inside and those metered outside of the network altogether (up to 10.9%). Reduction of the queue lengths inside the network through metering was observed to a point where green time was efficiently utilized. However, metering to points well below oversaturation or exceeding the maximum throughput of a single intersection did not always provide network improvements. This suggests an optimal congestion level in the network, which can be achieved by a metering strategy. The analysis of the metering effects is presented for a case study, along benefits and scenarios where metering can be applied.
  Authors: Medina, Juan C.; Hajbabaie, Ali; Benekohal, Rahim F.
  Authors: Medina, Juan C.; Hajbabaie, Ali; Benekohal, Rahim F.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-4294
• Probability Model for Understanding Effect of Detector Delay on Right-Turn-on-Red Traffic
  Abstract: Detector delay as a useful detector timing feature is often recommended to minimizing the disruptions on major movements by one or more minor movements. However, this benefit of detector delay is not always certain, because the applicability of detector delay is subject to a combination of gap demand, gap availability, critical gap acceptance, follow-up headways and other factors. Improper use of detector delay could be costly to the traffic on minor streets. With very limited literature, the complex relationship between detector delays and different critical factors has been fully understood. This paper presents an analytical model for estimating the probability of clearing the right-turn-on-red (RTOR) queues within the period of detector delay. This probability is the important first step to the understanding of how this detector feature affects the intersection operational efficiency. The gap-finding process of multiple RTOR vehicles is divided into several realistic cases and analyzed in great details. Insights of the process described in each case have been applied to the derivation of the probability model. Validation of the model is conducted using more than 4000 simulation runs. And a close fit is found between the computed probability and the simulated data, with errors no larger than 5.7% of the targeted values. The method to derive the probability model provides a stepping stone to derive the delay distributions for RTOR traffic.
  Authors: Zeng, Xiaosi; Zhang, Yunlong; Songchitruksa, Praprut
  Authors: Zeng, Xiaosi; Zhang, Yunlong; Songchitruksa, Praprut
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-4047
• Development and Use of Critical Functional Requirements for Controller Upgrade Decisions
  Abstract: Modern traffic signal controllers usually have to adopt to local transportation agency requirements. The standardization of controller hardware under Advanced Transportation Controller standard provided the flexibility for customized development of controller software. This resulted in a multitude of market controller software features that are challenging to evaluate. This paper presents a decision-support system based on a Multi-Criteria Decision Making (MCDM) technique for evaluation of traffic signal controllers. The method to evaluate the controllers is based on the set of Critical Functional Requirements for signalized intersections. The method was developed for a signal system under purview of Virginia Department of Transportation (VDOT). The critical functional requirements were developed through discussion with professionals in the field of signal system operations across North America. Criteria for scoring the controller features were developed from the information obtained from the controller manuals, vendors, software-in-the-loop and hardware-in-the-loop testing, survey of agencies, etc. A presentation of the proposed framework, with evaluation for three different controllers is included. In addition, presented are accompanying decision-support visualization aids. Alternate methods were also suggested for evaluation purpose, leaving opportunities for further research.
  Authors: Abbas, Montasir M.; Mladenovic, Milos; Kasaraneni, Yatish; Ganta, Surender; McGhee, Catherine
  Authors: Abbas, Montasir M.; Mladenovic, Milos; Kasaraneni, Yatish; Ganta, Surender; McGhee, Catherine
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-4758
• A Coordinated Optimization Model for Signal Timings of Full Continuous Flow Intersection
  Authors: You, Xiaoming
  Authors: You, Xiaoming
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-2643
• Research on Dynamic Signal Control for Exclusive Right-Turn Lane at Mixed Traffic Flow Intersections
  Authors: Zhao, Li
  Authors: Zhao, Li
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-3206
• Research on Dynamic Signal Control for Exclusive Right-Turn Lane at Mixed Traffic Flow Intersections
  Authors: Sun, Jian
  Authors: Sun, Jian
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-3206
• Self-Organizing Control Logic for Oversaturated Arterials
  Authors: Cesme, Burak
  Authors: Cesme, Burak
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-3218
• Multiregime Adaptive Signal Control for Congested Urban Roadway Networks
  Authors: Xin, Wuping
  Authors: Xin, Wuping
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-4154
• A Link-based Mixed Integer LP Approach for Adaptive Traffic Signal Control
  Authors: Han, Ke
  Authors: Han, Ke
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-4288
• SURTRAC: Scalable Urban Traffic Control
  Authors: Barlow, Gregory
  Authors: Barlow, Gregory
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-0315
• Research on Dynamic Signal Control for Exclusive Right-Turn Lane at Mixed Traffic Flow Intersections
  Authors: Wu, Zhizhou
  Authors: Wu, Zhizhou
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-3206
• Experiences with Adaptive Signal Control in Germany
  Abstract:

  Germany has a long tradition of traffic actuated and of coordinated signal control. In recent years a specific approach of traffic actuation, called model-based systems or adaptive control has found its way into practice. A scientific research on the performance of these systems has been conducted in the city of Muenster/Germany. The coordinated signal control system on the 6 km long arterial “Albersloher Weg” with 24 signalized intersections has been completely renewed by three steps: the old system, a rule-based traffic actuation, and an adaptive system. This process has been evaluated by a university research team using empirical studies. The results showed that the conventional actuated signal control has improved the traffic performance in a first step. By the additional use of the adaptive signal control system MOTION another significant improvement in traffic performance could be achieved. Speaking in rough figures, the traffic flow performance could be improved by 30 percent. Nevertheless, further developments are required to meet the expectation by city engineers and by road users.

  Authors: Brilon, Werner; Wietholt, Thomas; Pott, Andreas; Zelke, Ulrich
  Authors: Brilon, Werner; Wietholt, Thomas; Pott, Andreas; Zelke, Ulrich
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-1155
• A Link-based Mixed Integer LP Approach for Adaptive Traffic Signal Control
  Abstract:

  This paper is concerned with adaptive signal control problems on a road network, using a link-based kinematic wave model (Han et al., 2012). Such a model employs the Lighthill-Whitham-Richards model with a triangular fundamental diagram. A variational type argument (Lax, 1957; Newell, 1993) is applied so that the system dynamics can be determined without knowledge of the traffic state in the interior of each link. A Riemann problem for the signalized junction is explicitly solved; and an optimization problem is formulated in continuous-time with the aid of binary variables. A time-discretization turns the optimization problem into a mixed integer linear program (MILP). Unlike the cell-based approaches (Daganzo, 1995; Lin and Wang, 2004; Lo, 1999b), the proposed framework does not require modeling or computation within a link, thus reducing the number of (binary) variables and computational effort.The proposed model is free of vehicle-holding problems, and captures important features of signalized networks such as physical queue, spill back, vehicle turning, time-varying flow patterns and dynamic signal timing plans. The MILP can be efficiently solved with standard optimization software.

  Authors: Han, Ke; Friesz, T. L.; Yao, Tao
  Authors: Han, Ke; Friesz, T. L.; Yao, Tao
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 541
  Paper Number: 13-4288