Using Automatic Calibration with Microscopic Traffic Simulation

Author(s):  
Iisakki Kosonen ◽  

The microscopic simulation is getting increasingly common in traffic planning and research because of the detailed analysis it can provide. The drawback of this development is that the calibration and validation of such a detailed simulation model can be very tedious. This paper summarizes the research on automatic calibration of a high-fidelity micro-simulation (HUTSIM) at the Helsinki University of Technology (TKK). In this research we used ramp operation as the case study. The automatic calibration of a detailed model requires a systematic approach. A key issue is the error-function, which provides a numeric value to the distance between simulated and measured results. Here we define the distance as combination of three distributions namely the speed distribution, gap distribution and lane distribution. We developed an automated environment that handles all the necessary operations. The system organizes the files, executes the simulations, evaluates the error and generates new parameter combinations. For searching of the parameter space we used a genetic algorithm (GA). The overall results of the research were good demonstrating the potential of using automatic processes in both calibration and validation of simulation models.

Author(s):  
Byungkyu (Brian) Park ◽  
Hongtu (Maggie) Qi

Microscopic traffic simulation models have been playing an important role in the evaluation of transportation engineering and planning practices for the past few decades, particularly in cases in which field implementation is difficult or expensive to conduct. To achieve high fidelity and credibility for a traffic simulation model, model calibration and validation are of utmost importance. Most calibration efforts reported in the literature have focused on the informal practice, and they have seldom proposed a systematic procedure or guideline for the calibration and validation of simulation models. This paper proposes a procedure for microscopic simulation model calibration. The validity of the proposed procedure was demonstrated by use of a case study of an actuated signalized intersection by using a widely used microscopic traffic simulation model, Verkehr in Staedten Simulation (VISSIM). The simulation results were compared with multiple days of field data to determine the performance of the calibrated model. It was found that the calibrated parameters obtained by the proposed procedure generated performance measures that were representative of the field conditions, while the simulation results obtained with the default and best-guess parameters were significantly different from the field data.


Author(s):  
Byungkyu (Brian) Park ◽  
J. D. Schneeberger

Microscopic simulation models have been widely used in both transportation operations and management analyses because simulation is safer, less expensive, and faster than field implementation and testing. While these simulation models can be advantageous to engineers, the models must be calibrated and validated before they can be used to provide meaningful results. However, the transportation profession has not established any formal or consistent guidelines for the development and application of these models. In practice, simulation model–based analyses have often been conducted under default parameter values or bestguessed values. This is mainly due to either difficulties in field data collection or lack of a readily available procedure for simulation model calibration and validation. A procedure was proposed for microscopic simulation model calibration and validation and an example case study is presented with real-world traffic data from Route 50 on Lee Jackson Highway in Fairfax, Virginia. The proposed procedure consisted of nine steps: ( a) measure of effectiveness selection, ( b) data collection, ( c) calibration parameter identification, ( d) experimental design, ( e) run simulation, ( f) surface function development, ( g) candidate parameter set generations, ( h) evaluation, and ( i) validation through new data collection. The case study indicates that the proposed procedure appears to be properly calibrating and validating the VISSIM simulation model for the test-bed network.


Author(s):  
Tomer Toledo ◽  
Haris N. Koutsopoulos ◽  
Angus Davol ◽  
Moshe E. Ben-Akiva ◽  
Wilco Burghout ◽  
...  

The calibration and validation approach and results from a case study applying the microscopic traffic simulation tool MITSIMLab to a mixed urban-freeway network in the Brunnsviken area in the north of Stockholm, Sweden, under congested traffic conditions are described. Two important components of the simulator were calibrated: driving behavior models and travel behavior components, including origin–destination flows and the route choice model. In the absence of detailed data, only aggregate data (i.e., speed and flow measurements at sensor locations) were available for calibration. Aggregate calibration uses simulation output, which is a result of the interaction among all components of the simulator. Therefore, it is, in general, impossible to identify the effect of individual models on traffic flow when using aggregate data. The calibration approach used takes these interactions into account by iteratively calibrating the different components to minimize the deviation between observed and simulated measurements. The calibrated MITSIMLab model was validated by comparing observed and simulated measurements: traffic flows at sensor locations, point-to-point travel times, and queue lengths. A second set of measurements, taken a year after the ones used for calibration, was used at this stage. Results of the validation are presented. Practical difficulties and limitations that may arise with application of the calibration and validation approach are discussed.


1998 ◽  
Vol 1644 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Yunlong Zhang ◽  
Larry E. Owen ◽  
James E. Clark

The purpose of this paper is to explore various traffic modeling aspects and theories that may overcome some of the limitations in existing microscopic simulation models. A multiregime microscopic traffic simulation approach has been formulated featuring realistic and comprehensive carfollowing and lane-changing logic. A prototype implementation of the multiregime approach was developed in C++ and extensively tested. The multiregime simulation results demonstrate the efficiency and validity of the proposed models for a broad range of traffic scenarios. The test and validation results indicate that the model and program outperformed traditional methods and other existing traffic simulation programs. The validity and efficiency of the model is attributed to the fact that the regimes were added to the model incrementally to reflect increasing agreement with real-world traffic flow. The techniques and corresponding models will be used to improve existing microscopic traffic simulation models and programs.


1999 ◽  
Vol 26 (6) ◽  
pp. 840-851 ◽  
Author(s):  
A F Al-Kaisy ◽  
J A Stewart ◽  
M Van Aerde

Microscopic traffic simulation models are being increasingly used to evaluate Intelligent Transportation Systems (ITS) strategies and to complement empirical data in developing new analytical procedures and methodologies. Lane changing rules are an essential element of any microscopic traffic simulation model. While most of these rules are based on theories and hypotheses, to date no attempt has been made to investigate the consistency of lane changing behaviour from microscopic simulation with empirical observations. The research presented in this paper examined this consistency at freeway weaving areas using empirical data. These data were collected in the late 1980s at several major freeway weaving sections in the State of California. The microscopic traffic simulation model INTEGRATION was used to perform simulation experiments in this research. Vehicle distributions, both total and by type of movement, were used as measures to investigate the lane changing activity that took place at these freeway areas. This examination revealed significant agreement between patterns of lane changing behaviour as observed in the field and as reproduced by microscopic simulation. Most quantitative discrepancies were shown to be a function of user-specified input data or due to some inherent limitations in the empirical data.Key words: simulation, lane changing, weaving, freeways.


Author(s):  
Burak Cesme ◽  
Selman Z. Altun ◽  
Barrett Lane

Transit preferential treatments offer the potential to improve transit travel time and reliability. However, the benefits of these treatments vary greatly depending on the specific characteristics of the study area, including turning movement and pedestrian volumes, signal timing parameters, and transit stop location. To evaluate the performance of preferential treatments, practitioners typically rely on microscopic simulation models, which require a considerable amount of effort, or a review of previous studies, which may reflect a bias toward the area characteristics. This paper develops a test bed and a planning-level framework to help practitioners determine benefits offered by various preferential treatments without developing a detailed simulation model. To evaluate preferential treatment benefits, the authors performed extensive simulation runs under various scenarios at an isolated intersection with VISSIM. The analyses show that the greatest benefit comes from relocating a nearside stop to a farside stop, in which farside stops can reduce delay up to 30 s per intersection. The highest saving that could be obtained with a queue jump lane is approximately 9 s per intersection. As the number of right turns increases along with the number of conflicting pedestrians, the benefit of a queue jump lane disappears. Transit signal priority with 15 s of green extension and red truncation can offer up to 19 s of reduction in delay; the benefits become more pronounced with a high volume-to-capacity (v/c) ratio. With a low v/c ratio, granting 10 s of green extension without red truncation provides very marginal benefits; only a 2-s delay reduction per intersection is gained.


Author(s):  
Wilco Burghout ◽  
Haris N. Koutsopoulos ◽  
Ingmar Andréasson

Traffic simulation is an important tool for modeling the operations of dynamic traffic systems. Although microscopic simulation models provide a detailed representation of the traffic process, macroscopic and mesoscopic models capture the traffic dynamics of large networks in less detail but without the problems of application and calibration of microscopic models. This paper presents a hybrid mesoscopic–microscopic model that applies microscopic simulation to areas of specific interest while simulating a large surrounding network in less detail with a mesoscopic model. The requirements that are important for a hybrid model to be consistent across the models at different levels of detail are identified. These requirements vary from the network and route choice consistency to the consistency of the traffic dynamics at the boundaries of the microscopic and mesoscopic submodels. An integration framework that satisfies these requirements is proposed. A prototype hybrid model is used to demonstrate the application of the integration framework and the solution of the various integration issues. The hybrid model integrates MITSIMLab, a microscopic traffic simulation model, and Mezzo, a newly developed mesoscopic model. The hybrid model is applied in two case studies. The results are promising and support both the proposed architecture and the importance of integrating microscopic and mesoscopic models.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Xingan (David) Kan ◽  
Lin Xiao ◽  
Hao Liu ◽  
Meng Wang ◽  
Wouter J. Schakel ◽  
...  

Realistic microscopic traffic simulation is essential for prospective evaluation of the potential impacts of new traffic control strategies. Freeway corridors with interacting bottlenecks and dedicated lanes generate complex traffic flow phenomena and congestion patterns, which are difficult to reproduce with existing microscopic simulation models. This paper discusses two alternative driving behavior models that are capable of modeling freeways with multiple bottlenecks and dedicated lanes over an extended period with varying demand levels. The models have been calibrated using archived data from a complicated 13-mile long section of the northbound SR99 freeway near Sacramento, California, for an 8-hour time period in which the traffic fluctuated from free-flow to congested conditions. The corridor includes multiple bottlenecks, multiple entry and exit ramps, and an HOV lane. Calibration results show extremely good agreement between field data and model predictions. The models have been cross-validated and produced similar macroscopic traffic performance. The main behavior that should be captured for successful modeling of such a complex corridor includes the anticipative and cooperative driver behavior near merges, lane preference in presence of dedicated lanes, and variations in desired headway along the corridor.


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