Traffic Simulation Software Research Articles

Modification in Hcm Delay Model for Roundabout for Mixed Traffic Conditions - a Pilot Study

Roundabouts have proven to be an effective intersection design method for smooth traffic flow movements and improved safety. Previous studies show that VISSIM, commercial traffic simulation software, can be used as a proficient tool for modeling and efficiently analyzing roundabouts. This paper focuses on developing a methodology for modeling roundabouts in India using VISSIM. Three typical roundabouts were chosen from the northern part of India. Calibration and validation of the model were performed to ensure the correctness of the model. The average delay and volume to capacity ratio (v/c ratio) were compared for developing the level of service (LOS) thresholds for Indian conditions. The thresholds are compared with existing guidelines provided by the HCM 2010 and AUSTROADS. In addition, the methodology for determining modification factors for applying HCM 2010 delay model in Indian traffic conditions is defined.

Virtual subjective and objective evaluation method of traffic jam assist

The virtual subjective and objective evaluation method is a significant development method to improve the performance of Traffic Jam Assist (TJA). This paper proposed a virtual subjective and objective evaluation method of TJA, including test scenarios and evaluation indices. Firstly, the paper built a virtual test and evaluation platform for intelligent vehicles based on a high-fidelity driving simulator and VTD traffic simulation software. Secondly, the paper proposed an objective evaluation system composed of evaluation indices, 11 test scenarios, and 49 test cases. Thirdly, the paper put forward a subjective evaluation system composed of three indices: acceptance, comfort, and psychological load. Finally, the paper used the platform mentioned above to conduct subjective and objective tests and evaluations of the TJA system that comes from Matlab. Meanwhile, objective and subjective evaluation scoring results were obtained. The evaluation results showed that the subjective and objective evaluation method proposed in this paper can test the objective and subjective performance of the TJA system comprehensively and systematically, which provided a guarantee for the improvement of the TJA system.

How PTV Vissim Has Been Calibrated for the Simulation of Automated Vehicles in Literature?

Recently, in the literature, microscopic simulation is one of the most attractive methods in impact assessment of automated vehicles (AVs) on traffic flow. AVs can be divided into different categories, each having different driving characteristics. Hence, calibrating microscopic simulators for different AV categories could be challenging in AVs’ impact assessment. The PTV Vissim microscopic traffic simulation software has been calibrated for simulating diverse types of AVs in a large body of literature. There are two main streams of studies in literature adapting AVs' driving behaviors in Vissim following either internal (i.e., adjusting the parameters of the Vissim's default driving behavior models) or external (i.e., adapting AVs' behavior through external VISSIM interfaces) modeling approaches. The current paper investigates how the PTV Vissim has been internally calibrated for the simulation of different types of AVs and compares the calibrated values in the literature with default values introduced in the recent version of PTV Vissim. In the present paper, the reviewed studies are partitioned into two main categories according to the characteristics of the studied AVs, the studies focused on autonomous automated vehicles (AAVs) and the ones focused on cooperative automated vehicles (CAVs). Our findings indicate that the literature expects a lower value for parameters including standstill distance (CC0), headway time (CC1), following variation (CC2), the threshold for entering “following” (CC3), negative/positive following thresholds (CC4/CC5), speed dependency of oscillation (CC6), oscillation acceleration (CC7), safety distance reduction factor (SDRF), and minimum headway front/rear (MinHW) for AVs than conventional vehicles (CVs). Besides, the literature expects higher values for parameters including standstill acceleration (CC8), acceleration at 80 km/h (CC9), looking distances, and maximum deceleration for cooperative braking (MaxDCB) for AVs. When cautious AVs are introduced, deterring effects are expected in the literature (e.g., higher CC0). Moreover, CAVs can have higher looking distance values compared with AAVs.

An Intersection Platoon Speed Control Model Considering Traffic Efficiency and Energy Consumption in CVIS

This paper proposed an intersection platoon speed control model considering traffic efficiency and energy consumption in the cooperative vehicle-infrastructure systems (CVIS) environment. This model divides the control situation in detail according to the different state of signal lights at the intersection and splits the platoon that cannot pass the intersection completely. The optimization model is established by taking the traffic delay and energy consumption of the platoon as the control objectives, and the model is solved by using a genetic algorithm (GA). Finally, the simulation platform is built by SUMO traffic simulation software, MATLAB, and Python to verify the model. The simulation results show that the total number of queued vehicles, the maximum number of queued vehicles, and the mean travel time of vehicles decreased by 77.81%, 33.33%, and 10.95%, respectively. Besides, the total fuel consumption is reduced by 19.95%, the total emissions of CO2, CO, HC, NOx, and PMx decreased by 19.96%, 58.55%, 51.33%, 23.81%, and 37.51%, respectively. It indicates that the proposed platoon speed control model can effectively improve traffic efficiency while reducing energy consumption and pollutant emissions.

Evaluation of Intersection Properties Using MARS Method for Improving Urban Traffic Performance: Case Study of Tekirdağ, Turkey

Increasing urban traffic performance is a technical problem that has been investigated by many researchers these days. Traffic performance can be increased in many ways, as part of the transportation planning process, on smaller scales, or with different methods and techniques. The determination of traffic intervention areas in urban transportation planning is an intervention type that determines the rate at which the traffic performance will increase. Although transportation planning is an integrated issue, the type of traffic modification and prior intervention on intersections are often determined with partitive paradigms and strategies. It is a significant opportunity for decision makers to be informed in advance of the effects of intersection characteristics on the overall traffic performance. However, it is not an attempted or tested concept to perform a general assessment of the impact of the intersection characteristics on the overall performance of the intersections. In this study, a four-stage integrated analysis including the multivariate adaptive regression splines (MARS) method is proposed for the overall traffic performance evaluation. The traffic characteristics of intersections are first indexed and categorized. The intersection performance results are then obtained using the VISSIM traffic simulation software. Subsequently, the relationship between them is determined with the MARS method, and the effects of the intersection characteristics on the traffic performance are investigated. Tekirdağ, a metropolitan city located in northwestern Turkey, is selected for the case study. According to the obtained simulation results, the suggestions related to the development of intersection performances are made and tested.

The Space-Based Car-Following Model: Development and Application for Managed Motorway System Safety Evaluation

Traffic safety studies need more than what the current micro-simulation models can provide, as they presume that all drivers exhibit safe behaviors. Therefore, existing micro-simulation models are inadequate to evaluate the safety impacts of managed motorway systems such as Variable Speed Limits. All microscopic traffic simulation packages include a core car-following model. This paper highlights the limitations of the existing car-following models to emulate driver behaviour for safety study purposes. It also compares the capabilities of the mainstream car-following models, modelling driver behaviour with precise parameters such as headways and time-to-collisions. The comparison evaluates the robustness of each car-following model for safety metric reproductions. A new car-following model, based on the personal space concept and fish school model is proposed to simulate more accurate traffic metrics. This new model is capable of reflecting changes in the headway distribution after imposing the speed limit from variable speed limit (VSL) systems. This model can also emulate different traffic states and can be easily calibrated. These research findings facilitate assessing and predicting intelligent transportation systems effects on motorways, using microscopic simulation.

Interactive Web Application for Traffic Simulation Data Management and Visualization

As traffic simulation software becomes more effective for realistically simulating and analyzing traffic dynamics and vehicle interactions on the mesoscopic and microscopic level, the management, dissemination, and collaborative visualization of traffic simulation results produced by individual transportation planners presents a significant challenge. Existing online content management systems have a very limited capability in allowing users to query specific traffic simulation scenarios and geospatially visualize simulation results through shareable and interactive web interfaces. This paper presents a web-based application for promoting the archiving, sharing, and visualization of large-scale traffic simulation outputs. The application is developed to enhance cyber-physical controls, communications, and public education for collaborative transportation planning. Unique features of the web application include: (a) allowing users to upload their new traffic simulation scenarios (parameters and outputs), as well as search existing scenarios using easily accessible interfaces; (b) optimizing simulation output files with heterogeneous data formats and projected coordinate systems for web-based storage and management using a scalable and searchable data/metadata standard; (c) standardizing user-uploaded simulation outputs using web interfaces and data processing libraries with parallel computing capacity; and (d) providing shareable web visual interfaces for visualizing the traffic flow and signal information stored in simulation outputs (e.g., regional traffic patterns and individual vehicle interactions) and visually comparing multiple simulation outputs both spatially and temporally. The paper presents the conceptual design and implementation of this application, and demonstrates the application’s performance for sharing, comparing, and visualizing simulation outputs from VISSIM and SUMO, two commonly used traffic simulation software programs.

Using Hybrid Clustering to Approximate Fastest Paths on Urban Networks

Estimating fastest paths on large networks is a crucial problem for dynamic route guidance systems. The present paper proposes a statistical approach for approximating fastest paths on urban networks. The traffic data used for conducting the statistical analysis is generated using a macroscopic traffic simulation software developed by us. The traffic data consists of the input flows, the arc states or the number of cars in the arcs and the paths joining the various origins and the destinations of the network. To find out the relationship between the input flows, arc states and the fastest paths of the network, we subject the traffic data to hybrid clustering. The hybrid clustering uses two methods namely k-means and Ward’s hierarchical agglomerative clustering. The strength of the relationship among the traffic variables was measured using canonical correlation analysis. The results of hybrid clustering are decision rules that provide fastest paths as a function of arc states and input flows. These decision rules are stored in a database for performing predictive route guidance. Whenever a driver arrives at the entry point of the network, the current arc states and input flows are matched against the database parameters. If agreement is found, then the database provides the fastest path to the driver using the corresponding decision rule. In case of disagreement, the database recommends the driver to choose the shortest path as the fastest path in order to reach the destination.

Signal timing optimization design of cross intersection-- A Case study of The intersection of Minzhu South Road and Fengshou Road in Jiaozuo City

The capacity of intersection affects the maximum capacity of road to a certain extent. The traffic capacity of the intersection can be improved to some extent by optimizing and adjusting the parameters of the signal timing model. Taking the cross-type intersection at the intersection of Minzhu South Road and Fengshou Road in Jiaozuo City as the research background, this study optimizes the signal timing design for the current intersection, optimizes the signal timing design by using Webster algorithm, and conducts simulation by using traffic simulation software VISSIM. The results showed that the average delay at the intersection was reduced by nearly seven seconds.

Design of On-line Simulation System for Signal Control of Urban Intersections Based on Visual Sensing Technology

Intersection area is the area with the most serious conflicts and accidents in the whole urban traffic system. Therefore, it is of great significance to combine modern computer technology, sensing technology and communication technology to intelligently control intersections, improve the efficiency of traffic signal control and reduce the delay time in conflict areas. Starting with video detection and using deep learning in the detection module, a video detection mechanism based on restricted Boltzmann machine network is proposed. Based on C # programming language, the intersection traffic signal simulation module is designed through COM interface provided by traffic simulation software VISSIM, which realizes road network import, parameter setting, signal timing change, simulation operation and simulation result output. Numerical experiments show that fuzzy control method with self-correcting factor is superior to timing control method and classical fuzzy control method in average delay time of vehicles.

Validation of a Customized Local Traffic Simulator (LocalSim)

Traffic management offices in the Philippines commonly rely on experimentation or the trialand-error implementation of traffic management schemes to solve the growing traffic problem. This method is unreliable, time-consuming, costly, and inconvenient to road users who are often not aware of the sudden changes in traffic rules, regulations, and road configuration. One possible way to test the effectiveness of proposed traffic schemes is by implementing them in silico or by computer simulation. There are traffic simulation software programs available in the market, but they are either too expensive for massive use of the different local government units (LGUs) and/or too general such that they are unable to replicate some features of Filipino driving behavior. It is under this backdrop how LocalSim was conceptualized: A traffic simulation software customized to the needs of the different LGUs with driving models designed to capture Filipino driving behavior. This study presents the model validation performed, which proves that LocalSim can generate simulation results that are acceptable representations of the real-world scenario. The study area is the EDSA–Quezon Ave Intersection where the in situ or on-site traffic behavior was measured using the selected measure of performance (MOP) and evaluated with Theil’s indicator.

Software Framework for Testing of Automated Driving Systems in the Traffic Environment of Vissim

As the complexity of automated driving systemss (ADSs) with automation levels above level 3 is rising, virtual testing for such systems is inevitable and necessary. The complexity of testing these levels lies in the modeling and calculation demands for the virtual environment, which consists of roads, traffic, static and dynamic objects, as well as the modeling of the car itself. An essential part of the safety and performance analysis of ADSs is the modeling and consideration of dynamic road traffic participants. There are multiple forms of traffic flow simulation software (TFSS), which are used to reproduce realistic traffic behavior and are integrated directly or over interfaces with vehicle simulation software environments. In this paper we focus on the TFSS from PTV Vissim in a co-simulation framework which combines Vissim and CarMaker. As it is a commonly used software in industry and research, it also provides complex driver models and interfaces to manipulate and develop customized traffic participants. Using the driver model DLL interface (DMDI) from Vissim it is possible to manipulate traffic participants or adjust driver models in a defined manner. Based on the DMDI, we extended the code and developed a framework for the manipulation and testing of ADSs in the traffic environment of Vissim. The efficiency and performance of the developed software framework are evaluated using the co-simulation framework for the testing of ADSs, which is based on Vissim and CarMaker.

Evaluation of Freeway Traffic Management and Control Measures Based on SUMO

With the rapid increase of freeway traffic volume, traffic congestion has become a normal phenomenon, through scientific freeway management and control measures, the traffic efficiency of the whole road can be effectively improved and the congestion problem can be alleviated. Therefore, this paper takes Shaoxing section of Shanghai-Hangzhou-Ningbo Feeway as the research object, puts forward three active traffic control measures, and uses the traffic simulation software SUMO to simulate and evaluate the effect of the freeway control measures. The results show that emergency lane control measure, ramp metering control measure, and variable speed limit control measure can effectively reduce the delay of freeway in the congested section, and improve road capacity. In this paper, the study of freeway management and control measures under congestion conditions, provides relevant decision support and theoretical guidance for freeway management.

DEFINITION OF A PYTHON SCRIPT FOR THE MICRO-SIMULATION OF THE TRUCK PLATOONING SYSTEM

Truck platooning is, by now, one of the major topics in transport science and freight transport. The benefits arising from the system explain the growing interest of the involved stakeholders and the many field-tests planned in the next years. This run towards truck platooning saw an abrupt acceleration but there are risks that should be accounted for. Even though field-tests are fundamental for the implementation of a new transport system, they will hardly cover all the traffic scenarios that a platoon of trucks will face on the European network. Therefore, there is the need for many more studies based on traffic simulation and for tools enabling traffic simulation software to reproduce truck platooning. In this framework, the paper has two aims, the first one being to report and describe a Python script to reproduce truck platooning with a common commercial simulation software. The second one is to apply said script to analyse what is the best driving strategy for a platoon of truck to limit the hindrance on the surrounding traffic while approaching a critical highway segment such as the on-ramp one. At the end of the paper, a comparison between three different strategies (driving as usual, dissolution and headway adaptation) is carried out and commented.

Evaluation of Microsimulation Models for Roadway Segments with Different Functional Classifications in Northern Iran

Industrialization, urban development, and population growth in the last decades caused a significant increase in congestion of transportation networks across the world. Increasing congestion of transportation networks and limitations of the traditional methods in analyzing and evaluating the congestion mitigation strategies led many transportation professionals to the use of traffic simulation techniques. Nowadays, traffic simulation is heavily used in a variety of applications, including the design of transportation facilities, traffic flow management, and intelligent transportation systems. The literature review, conducted as a part of this study, shows that many different traffic simulation packages with various features have been developed to date. The present study specifically focuses on a comprehensive comparative analysis of the advanced interactive microscopic simulator for urban and non-urban networks (AIMSUN) and SimTraffic microsimulation models, which have been widely used in the literature and practice. The evaluation of microsimulation models is performed for the four roadway sections with different functional classifications, which are located in the northern part of Iran. The SimTraffic and AIMSUN microsimulation models are compared in terms of the major transportation network performance indicators. The results from the conducted analysis indicate that AIMSUN returned smaller errors for the vehicle flow, travel speed, and total travel distance. On the other hand, SimTraffic provided more accurate values of the travel time. Both microsimulation models were able to effectively identify traffic bottlenecks. Findings from this study will be useful for the researchers and practitioners, who heavily rely on microsimulation models in transportation planning.

Benefits of connected vehicle signalized left-turn assist: Simulation-based study

Simulation modeling can play a major role in supporting the pre-deployment and post-deployment assessment of connected vehicle (CV) applications, particularly given the limited implementations of these applications and the low market penetrations of CV that can be expected in the near future. This study demonstrates the use of simulation modeling to assess the safety and mobility benefits of the Signalized Left Turn Assist (SLTA), a CV-based application at signalized intersections. The benefits of SLTA were analyzed in this study using a calibrated microscopic traffic simulation package. Real-world gap acceptance distribution was used in the calibration of the simulation model to better assess the impact of SLTA considering the real-world driver's behaviors at permissive left-turn signals. A method was developed to calibrate the utilized microscopic simulation model to reflect the real-world gap acceptance distributions.The study results show that SLTA can increase the left-turn capacity depending on the SLTA gap time parameter setting, reaching approximately 64.8%, 51.1%, and 35.9% when utilizing a gap time of 3 s, 4 s, and 5 s, respectively. In addition, the results show that with 100% utilization, the average delay for all vehicles can be reduced by approximately 58.4%. The safety benefits of the SLTA were determined utilizing surrogate measures based on vehicle trajectories generated by the microscopic traffic simulation model. The results show that by utilizing a 5-second predefined time gap in the SLTA application, the total number of observed crossing conflicts decreased from 6 conflicts per hour to zero conflicts per hour when the SLTA utilization rate increases from 0% to 100%.

WITHDRAWN: Enhancement of Al-Rawad intersection by using synchro traffic simulation software: As case study

Abstract The intersections have been generally undergone certain impacts from the transportation volumes particularly at capital Baghdad, the capital of Iraq. The intersections’ level of service (LOS) are improved via the traffic management system (TMSs) through decreasing the time waster throughout travel, delay, in addition to congestion. The presented study examined enhancing the TMS related to the Al-Rawad signalized intersection in the center of the city. On April 2019, video recording approaches used to collect traffic data. Synchro10 software has been used for evaluating and improving TMSs for the future and for present conditions. The results have indicated that the intersection that is operating on a Level of Service F which has an elevated delay of time (155.4 s/veh.) as well as volume to capacity ratio (v/c) which is equal to 1.46. After 20 years of carried out of this work, three alternative solutions intended for improving the traffic conditions taken into account changing geometric features with modifying and enhancing traffic signal’s timing plan. Proposal No. 3 reduced the average delay of the intersection and shows a good improved in LOS from F to C.

Simulating and assessing the effect of a protected intersection design for bicyclists on traffic operational performance and safety

The focus of this research is to simulate and assess the effect of a protected intersection design (PID) for bicyclists on traffic operational performance and safety. The PID was modelled and evaluated at the intersection of Tyvola Rd and South Blvd in Charlotte, North Carolina, USA. Traffic was modelled considering the existing intersection design and proposed PID using Vissim microscopic traffic simulation software under conditions of 0% bicycles to 15% bicycles. Safety was then analysed using Surrogate Safety Assessment Model (SSAM), and conflicts were defined as a 1.5-second intersection of two or more trajectories. There is no conclusive evidence that PID negatively effects operational performance (vehicle delay and level of service) at the selected study intersection. The type and total number of bicycle-related conflicts per bicycle varied with the percentage of bicycles. As much as an 80% reduction in the total number of bicycle-related conflicts could be observed if the percentage of bicycles exceed 10%. Benefits due to the implementation of PID could be greater at intersections with high bicycling activities. The findings support the hypothesis that the PID reduces the number of conflicts, and therefore improves safety.

Simulating the effectiveness of wave dissipation by FollowerStopper autonomous vehicles

The traffic jam phenomenon known as stop-and-go waves is commonplace on many roadways and is unavoidable due to the imperfect nature of human driving behaviour. Previous research by Stern et al. (2018) has demonstrated experimentally that a single Autonomous Vehicle (AV) can be harnessed to dissipate stop-and-go waves produced by 20 other passenger vehicles driving in a cycle. However, the experiment was conducted in an idealistic situation of a single-lane ring road with one AV; meaning no lane changing was possible and multiple AV interaction was left untested. To address these limitations, the AV driving behaviour used to achieve this, known as FollowerStopper (FS), was modelled for use in the Aimsun traffic simulation software and validated before further numerical experiments were conducted. The microsimulation scenarios were designed to observe how multiple AVs driven by the FS controller (referred to as FS-AVs in this paper) affect their traffic wave dissipation capability. Both single and double-lane ring roads experimental designs were used with the latter capturing the untested effect of lane changes. FS-AV was found to be less effective than originally documented in both cases. Multiple FS-AVs included within one lane were still able to improve traffic flow and dissipate the stop-and-go waves, although it is sensitive to the combination of different factors and any deviation away from the ideal condition is likely to produce worse-off traffic operations in terms of traffic flow. For double-lanes, human-driven vehicles (HDVs) would change lanes at heightened rates to occupy the larger gap the FS-AV needs for its dissipating strategy, causing it to further pullback and set off a chain reaction to upstream traffic. Stop-and-go waves had not been dissipated and decreased traffic performance in terms of flow, speed and delay time resulted. Our results also showed that the wave dampening effect of the FS-AV does not translate between the ring road and its linear equivalent. On the other hand, our preliminary simulation results using a real-life freeway model did not suggest multiple FS-AVs worsen traffic conditions. The contradicting results might be due to different traffic conditions such as vehicle density. Further research is required to investigate what factors could adversely affect FS-AV’s ability to dampen shockwaves and explore possible improvement to its driving algorithm.

Open source tools for geographic analysis in transport planning

Geographic analysis has long supported transport plans that are appropriate to local contexts. Many incumbent ‘tools of the trade’ are proprietary and were developed to support growth in motor traffic, limiting their utility for transport planners who have been tasked with twenty-first century objectives such as enabling citizen participation, reducing pollution, and increasing levels of physical activity by getting more people walking and cycling. Geographic techniques—such as route analysis, network editing, localised impact assessment and interactive map visualisation—have great potential to support modern transport planning priorities. The aim of this paper is to explore emerging open source tools for geographic analysis in transport planning, with reference to the literature and a review of open source tools that are already being used. A key finding is that a growing number of options exist, challenging the current landscape of proprietary tools. These can be classified as command-line interface, graphical user interface or web-based user interface tools and by the framework in which they were implemented, with numerous tools released as R, Python and JavaScript packages, and QGIS plugins. The review found a diverse and rapidly evolving ‘ecosystem’ tools, with 25 tools that were designed for geographic analysis to support transport planning outlined in terms of their popularity and functionality based on online documentation. They ranged in size from single-purpose tools such as the QGIS plugin AwaP to sophisticated stand-alone multi-modal traffic simulation software such as MATSim, SUMO and Veins. Building on their ability to re-use the most effective components from other open source projects, developers of open source transport planning tools can avoid ‘reinventing the wheel’ and focus on innovation, the ‘gamified’ A/B Street https://github.com/dabreegster/abstreet/#abstreet simulation software, based on OpenStreetMap, a case in point. The paper, the source code of which can be found at https://github.com/robinlovelace/open-gat, concludes that, although many of the tools reviewed are still evolving and further research is needed to understand their relative strengths and barriers to uptake, open source tools for geographic analysis in transport planning already hold great potential to help generate the strategic visions of change and evidence that is needed by transport planners in the twenty-first century.