U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
|This report is an archived publication and may contain dated technical, contact, and link information|
|Publication Number: FHWA-HRT-13-026 Date: March 2014|
Publication Number: FHWA-HRT-13-026
Date: March 2014
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The Federal Highway Administration, in support of the Traffic Analysis and Simulation Pooled Fund Study, initiated this study to provide guidance for analysts and modeling managers on successfully applying traffic simulation analyses. Currently, State and local agencies face challenges to make proper decisions on transportation improvement projects. The traffic analysis and application of the analysis tools may be limited or improperly scoped, leading to conclusions and decisions that may be compromised. Projects may not be scoped properly due to the complexity of the traffic analysis tools. The level of effort to get the quality output may not be known. As a result, agencies may not sufficiently fund these projects. This report presents systematic ways to determine the appropriate scope and budget for traffic analysis efforts using microsimulation, resulting in better project and program decisions on transportation improvement projects. The target audience for this report includes modeling managers and analysts.
Joseph I. Peters, Ph.D.
Director, Office of Operations
Research and Development
This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for its contents or use thereof. This report does not constitute a standard, specification, policy, or regulation.
The U.S. Government does not endorse products or manufacturers. Trade and manufacturers’ names appear in this report only because they are considered essential to the object of the document.
Quality Assurance Statement
The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.
Technical Report Documentation Page
|1. Report No.
|2. Government Accession No.||3 Recipient's Catalog No.|
|4. Title and Subtitle
Guidance on the Level of Effort Required to Conduct Traffic Analysis Using Microsimulation
5. Report Date
|6. Performing Organization Code|
Vassili Alexiadis, Jaimison Sloboden, Gustave Cordahi, and Randall VanGorder
8. Performing Organization Report No.
9. Performing Organization Name and Address
Cambridge Systematics, Inc.
10. Work Unit No. (TRAIS)
|11. Contract or Grant No.
|12. Sponsoring Agency Name and Address
Federal Highway Administration
|13. Type of Report and Period Covered
14. Sponsoring Agency Code
|15. Supplementary Notes
The Contracting Officer’s Technical Manager (COTM) was Randall VanGorder.
The purpose of this report is to provide guidance for analysts and modeling managers on successfully applying traffic simulation analyses. This report presents systematic ways to determine the appropriate scope and budget for traffic analysis efforts using microsimulation, resulting in better project and program decisions on transportation improvement projects.
This report focuses on conducting traffic analysis for geometric and operation design projects during a typical day. This type of analysis is customarily performed during project development by State transportation departments and reviewed by U.S. Department of Transportation staff for interstate access and other related requirements. This report is consistent with the seven-step process outlined in Traffic Analysis Toolbox Volume III: Guidelines for Applying Traffic Microsimulation Modeling Software.(1)
Considering that each transportation agency has unique needs and resources, this report can be used by any agency to develop its own framework for determining the level of effort. Putting into perspective the challenge of meeting the increasing needs of traffic analyses while keeping up with limited budgets, this report tackles different critical areas of those analyses by pinpointing best practices and identifying ways to tailor the level of effort invested to the analysis expectations.
|17. Key Words
Microsimulation, Modeling, Traffic analysis tools, Operations, Base model, Model calibration, Data collection, Analysis, Results, Statistical methodology, Alternative analysis
|18. Distribution Statement
No restrictions. This document is available through the National Technical Information Service, Springfield, VA 22161.
19. Security Classification
20. Security Classification
21. No. of Pages
|Form DOT F 1700.7 (8-72)||Reproduction of completed page authorized|
Figure 1. Illustration. I 35/CSAH 2 study area
Figure 2. Illustration. TH 100 study area
Figure 3. Illustration. I 5 Tacoma study area
Figure 4. Illustration. I 5 San Diego study area
Figure 5. Graph. Total level of effort comparison
Figure 6. Graph. Composite effort percentage by major tasks for all four case studies
Figure 7. Graph. Composite effort percentage by major tasks for small- and medium-sized models only
Figure 8. Graph. Agency responses of who conducted the analyses
Figure 9. Flowchart. Overview of analysis factors to be considered in selecting an analysis methodology/tool
Figure 10. Illustration. Turn percentage O-D-based approach
Figure 11. Illustration. Full O D-based approach
Figure 12. Illustration. Alternate full O-D-based network configuration
Figure 13. Illustration. O-D parallel facilities
Figure 14. Equation. Margin of error
Figure 15. Equation. Tolerance error percentage
Figure 16. Equation. Minimum number of model runs
Figure 17. Equation. Number of model runs example
Figure 18. Equation. Compare field data to model output
Figure 19. Graph. Normal distribution curve
Figure 20. Equation Sample calculation of ZCalculated
Figure 21. Flowchart. Alternatives analysis workflow
Figure 22. Illustration. Interstate access analysis requirements—analysis years
Figure 23. Illustration. Incomplete alternatives analysis approach
Figure 24. Illustration. Excessive alternative analysis
Figure 25. Illustration. Streamlined alternatives analysis method
Figure 26. Graph. Comparison of the effort for different alternative analysis approaches
Figure 27. Graph. Speed diagram for I 210 VISSIM simulation
Figure 28. Illustration. Sample comparison of project alternatives using schematic drawing
Figure 29. Graph. Delay by segment for two scenarios in vehicle-hours—I 210 VISSIM simulation
Figure 30. Graph. Delay by segment for all scenarios in vehicle-hours—I 210 VISSIM simulation
Table 1. Small model I 35 level-of-effort summary
Table 2. Medium model TH 100 level-of-effort summary
Table 3. Medium model I 5 Tacoma level-of-effort summary
Table 4. Large model I 5 San Diego level-of-effort summary
Table 5. Comparison of level of effort of sample projects
Table 6. Interviewee list
Table 7. Example data requirements for simulation
Table 8. Margin of error for different standard deviation to mean ratios
Table 9. Variability analysis of field data
Table 10. Sample statistical calculation to determine the minimum number of runs
Table 11. Sample calculation of field data
Table 12. Sample calculation of model statistics
Table 13. Error calculation of field data hourly volumes from 7:45 to 8:45 a.m
Table 14. Calculation of modeled speed data error and variation from 7:45 to 8:45 a.m
Table 15. Summary Table for minimum required number of model runs
Table 16. Trial 1 summary Table for minimum required number of model runs
Table 17. Hypothesis test trial 1
Table 18. Hypothesis test mainline location trial 2
Table 19. Sample MOE summary Table
Table 20. Delay comparison between two scenarios in vehicle-hours—I 210 VISSIM simulation