Office of Operations
21st Century Operations Using 21st Century Technologies

Traffic Analysis Toolbox Volume IV: Guidelines for Applying CORSIM Microsimulation Modeling Software

Contact Information: Doug Laird at

[PDF version, 7MB]

600 Maryland Avenue, SW, Suite 755
Washington, DC 20024

Research, Development, and Technology
Turner-Fairbank Highway Research Center
6300 Georgetown Pike
McLean, VA 22101-2296

Department of Transportation Logo
U.S. Department of Transportation
Federal Highway Administration
U.S. Department of Transportation
400 Seventh Street S.W., Room 4410 Washington , DC 20590
Publication No.: FHWA-HOP-07-079

Publication Date: January 2007

Table of Contents



Quality Assurance Statement

Technical Report Documentation Page

SI* (Modern Metric) Conversion Factors


1.0 Define the CORSIM Study

1.1 Study Purpose and Objectives

1.2 Study Scope

1.2.1  Freeway Projects
1.2.2  Arterial Projects
1.2.3  Combined Network Project (Corridor)
1.2.4  Temporal Scope
1.2.5  Design Year

1.3 Analytical Approach Selection

1.4 Analytical Tool Selection (Software)

1.4.1  CORSIM Capabilities and Limitations
1.4.2  TSIS Input/Output/Interface Support Tools
1.4.3  Third Party Products
1.4.4  User Training/Support
1.4.5  Ongoing Software Enhancements

1.5 Resource Requirements

1.5.1 Other Resource

1.6 Management of a CORSIM Study

1.7 Example Problem: Study Scope and Purpose

2.0 Data Collection and Preparation

2.1 Geometric Data

2.2 Demand Data

2.3 Control Data

2.3.1  Sign Data
2.3.2  Pre-Timed Signal Control Data
2.3.3  Actuated Signal Control Data
2.3.4  Pedestrian Demand Estimates
2.3.5  Ramp Meter Control Data

2.4 Calibration Data

2.4.1  Capacity and Saturation Flow Data
2.4.2  Point Speed Data
2.4.3  Travel Time Data
2.4.4  Delay and Queue Data

2.5 Field Inspection

2.6 Quality Assurance

2.6.1  Data Verificatio
2.6.2  Data Validation

2.7 Reconciliation of Traffic Counts

2.8 Example Problem: Data Collection and Preparation

3.0 Base Model Development

3.1 Create a New TSIS Project and TRAFED Network

3.1.1  Set the Simulation Run Control Data
3.1.2 Set the TRAFED Preferences

3.2 Link-Node Diagram: Model Blueprint

3.2.1  Nodes
3.2.2  Links
3.2.3  Surface Street Link Data
3.2.4  Corridors
3.2.5  Review

3.3 Traffic Demand Data

3.3.1  Entry Volume
3.3.2  Freeway Demand
3.3.3  Surface Street Demand
3.3.4  Vehicle Mix

3.4 Traffic Control

3.4.1  Freeway Ramp Meter Control
3.4.2  Arterial Control
3.4.3  Review

3.5 Traffic Operations and Management Data for Links

3.5.1  Modeling Traffic Incidents or Events
3.5.2  Incident Detection
3.5.3  Bus Operations
3.5.4  Pedestrian Interaction

3.6 Example Problem: Base Model Development

4.0 Error Checking

4.1 Review Software Errors

4.2 Review Input Data

4.2.1  CORSIM Input Data
4.2.2  CORSIM Diagnostics

4.3 Review Animation

4.4 Key Decision Point

4.5 Example Problem: Error Checking

5.0  Calibration

5.1 Objectives of Calibration

5.2 Calibration Approach

5.3 Establish Calibration MOEs and Targets

5.3.1  Selection of Calibration MOEs
5.3.2  Establishing Calibration Targets

5.4 CORSIM Run Considerations

5.4.1  Multiple CORSIM Runs
5.4.2  Simulation Time Frame
5.4.3  Exclusion of Initialization Period
5.4.4  Link Aggregations into Sections

5.5 Calibrate Capacity at Key Bottlenecks

5.5.1  Freeway Capacity Calibration
5.5.2  Surface Street Capacity Calibration

5.6 Calibrating Traffic Volumes

5.6.1  Freeway Traffic Volume Calibration
5.6.2  Surface Street Traffic Volume Calibration

5.7 Calibrating System Performance

5.7.1  Freeway System Performance Calibration
5.7.2  Calibrating Arterial System Performance

5.8 Key Decision Point: Check Overall Calibration Targets

5.9 Example Problem: Model Calibration

6.0  Alternatives Analysis

6.1 Baseline Demand Forecast

6.1.1  Demand Forecasting
6.1.2  Constraining Demand to Capacity
6.1.3  Allowance for Uncertainty in Demand Forecasts

6.2 Generation of Project Alternatives

6.3 Selection of Measures of Effectiveness (MOEs)

6.3.1  Candidate MOEs for Overall System Performance
6.3.2  Candidate MOEs for Localized Problems
6.3.3  Choice of Average or Worst Case MOEs

6.4 Model Application

6.4.1  Multiple CORSIM Runs
6.4.2  Exclusion of Initialization Period
6.4.3  Impact of Alternatives on Demand
6.4.4  Signal/Meter Control Optimization

6.5 Tabulation of Results

6.5.1  Numerical Output
6.5.2  Correcting Biases in the Results

6.6 Evaluation of Alternatives

6.6.1  Interpretation of System Performance Results
6.6.2  Hypothesis Testing
6.6.3  Confidence Intervals and Sensitivity Analysis
6.6.4  Comparing Results to Other Traffic Analysis Tools
6.6.5  Reviewing Animation Output
6.6.6  Comparison Techniques

6.7 Example Problem: Alternatives Analysis

7.0  Final Report and Technical Documentation

7.1 Final Report

7.2 Technical Report

7.2.1  Technical Memorandums

7.3 Presentation of a CORSIM Simulation Analysis

7.4 Example Problem: Final Report

Appendix A: Introduction to CORSIM Theory

Appendix B: CORSIM Capabilities and Limitations

Appendix C: Initialization Period

Appendix D: Generation and Usage of Random Numbers in CORSIM

Appendix E: Vehicle Entry Headway Generation in CORSIM

Appendix F: Actuated Signal Control

Appendix G: Error Checking Process – Coded Input Data Checklist

Appendix H: Understanding CORSIM Output

Appendix I: Frequently Asked Questions

Appendix J: Converting Between Systems of Actuated Control Parameters

Appendix K: Coding Techniques for Complex Situations

Appendix L: Run-Time Extension Overview

Appendix M: CORSIM Path Following Capability

Appendix N: Emergency Vehicle Operation

Appendix O: File Extensions





List of Figures

Figure 1. Flowchart.  CORSIM model development and application process

Figure 2. Chart. Selecting a peak period for analysis

Figure 3. Chart. Prototypical CORSIM analysis task sequence.

Figure 4. Graphic. Example problem: study map.

Figure 5. Graph. Example problem: peak period selection

Figure 6. Chart. Example problem: study schedule

Figure 7. Illustration. Traffic count example

Figure 8. Illustration. Example problem: aerial photo and planimetric map

Figure 9. Chart. Example problem: turning movement count

Figure 10. Illustration. Example problem: freeway bottleneck locations

Figure 11. Graph. Example problem: freeway travel time summary

Figure 12. Drawing. Example problem: HWY 100 lane geometry schematic

Figure 13. Drawing. Example problem: Minnetonka Blvd. lane geometry drawing

Figure 14. Illustration. Typical surface street node location

Figure 15. Illustration. Overlapped turn bay node location

Figure 16. Illustration. One-way street node location

Figure 17. Illustration. Freeway placement of nodes

Figure 18. Illustration. Node layout in TRAFED

Figure 19. Illustration. Freeway lane identification codes

Figure 20. Illustration. Freeway layout with 11 lanes

Figure 21. Illustration. Lane drop downstream of ramp meter

Figure 22. Illustration. Effects of incorrect link length

Figure 23. Illustration. TRAFVU intersection pull back

Figure 24. Chart. Surface street lane numbering

Figure 25. Illustration. Left turn channelization

Figure 26. Illustration. Sample lane alignment

Figure 27. Illustration. Turning alignments

Figure 28. Graph. Volume interpolation when not assigned for a time period

Figure 29. Illustration. Ramp-to-ramp trips

Figure 30. Illustration. Conditional turn movement example at diamond interchange

Figure 31. Illustration. TRAFED actuated control property dialog

Figure 32. Illustration. TRAFED pre-timed controller property dialog

Figure 33. Illustration. Example problem: HWY 100 link-node diagram

Figure 34. Illustration. Example problem: freeway origin-destination table

Figure 35. Illustration. Example problem: base model development review

Figure 36. Illustration. Example problem: HWY 100 northbound lane geometry schematic

Figure 37. Illustration. Example problem: link-node diagram of HWY 100 interchanges

Figure 38. Illustration. Example problem: volume error check at node 325, time period 1

Figure 39. Illustration. Example problem: volume error check at node 325, time period 4

Figure 40. Illustration. Example problem: sample signal timing sheet

Figure 41. Illustration. Example problem: sample signal plan schematic

Figure 42. Illustration. Example problem: TRAFVU detector error check

Figure 43. Illustration. Example problem: warning message from TRAFED-CORSIM translation

Figure 44. Illustration. Incorrect coding of lane drop

Figure 45. Flowchart. Calibration approach

Figure 46. Equation. Calculating the GEH Statistic (14)

Figure 47. Equation. Determining the appropriate number of simulation runs to complete

Figure 48. Illustration. Typical freeway bottleneck locations

Figure 49. Figure. Example of sensitivity of car following sensitivity  multiplier on throughput of a basic freeway segment

Figure 50. Figure. Example of sensitivity of mean discharge headway on  throughput of a signalized intersection approach

Figure 51. Figure. Example of comparing actual speed from field to modeled speed

Figure 52. Figure. Speed-volume relationship in CORSIM for a basic freeway segment

Figure 53. Illustration. Example problem: HWY 100 freeway bottleneck locations

Figure 54. Graph. Example problem: capacity calibration at northbound HWY 100/25th ½ Street Exit

Figure 55. Graph. Example problem: speed calibration results for  northbound HWY 100 during AM peak.

Figure 56. Graph. Example problem: speed calibration results for  northbound HWY 100 at WB TH 7 Exit during AM peak

Figure 57. Equation. Calculating the 95th percentile probable worst outcome

Figure 58. Formula. Determining the nearest neighbor value

Figure 59. Graph. Sample mean data graph for nearest neighbor example

Figure 60. Illustration. Washington State DOT traffic profile graph(20)

Figure 61. Illustration. Sample comparison of project alternatives using schematic drawing

Figure 62. Illustration. Example problem: traffic demand forecast at HWY 100/TH 7 interchange

Figure 63. Illustration. Example problem: alternatives generation and analysis process

Figure 64. Illustration. Example problem: visual comparison of HWY 100/TH 7 interchange alternatives

Figure 65. Graph. Maximum acceleration versus speed by performance index

Figure 66. Graph. Fuel consumption for different acceleration rates

Figure 67. Graph. Vehicles discharged from an internal link in equilibrium example

Figure 68. Illustration. Reaching equilibrium

Figure 69. Graph. Random variations in average speed among 10 runs

Figure 70. Equation. Schrage random number generator

Figure 71. Graph. Normal distribution

Figure 72. Graph. Exponential variates

Figure 73. Graph. Erlang distribution

Figure 74. Diagram. Typical traffic signal dual-ring diagram

Figure 75. Diagram. Standard NEMA phasing

Figure 76. Diagram. Lagging left turn phase

Figure 77. Diagram. Leading protected left turns on the main street, concurrent side-street phases

Figure 78. Diagram. Dual ring, leading protected left turns on the main street, split side-street phases

Figure 79. Diagram. Single Ring, Split Phasing

Figure 80. Formula. Extendable interval duration

Figure 81. Formula. Max phase green duration

Figure 82. Chart. Variable initial timing

Figure 83. Chart. Gap reduction concept

Figure 84. Illustration. Overlapping phase

Figure 85. Diagram. Pedestrian demand

Figure 86. Diagram. Typical coordination timing dial

Figure 87. Chart. Phase split diagram

Figure 88. Diagram. Examples of timing plan transitions

Figure 89. Graph. Cumulative versus interval data

Figure 90. Diagram. Control delay components

Figure 91. Equation. Control delay components

Figure 92. Equation. Calculating intersection control delay

Figure 93. Equation. Calculating intersection total delay

Figure 94. Diagram. Intersection phased in a quad left sequence

Figure 95. Formula. CORSIM yield point

Figure 96. Diagram. NETSIM offset versus NEMA offset

Figure 97. Diagram. Signal coordination parameters

Figure 98. Equations. Force off calculations

Figure 99. Equation. Permissive period 1

Figure 100. Equation. Permissive period 2

Figure 101. Equation. Permissive period 2 (recalculated)

Figure 102. Equation. Permissive period 3

Figure 103. Equation. Permissive period 3 (recalculated)

Figure 104. Illustration. Roundabout example in TRAFVU

Figure 105. Illustration. Dummy freeway sections

Figure 106. Illustration. Surface street section

Figure 107. Illustration. U-turn example

Figure 108. Illustration. Continuous left turn

Figure 109. Illustration.  Two controllers act as one controller to control two intersections

Figure 110. Illustration. Mid-block pedestrian actuated crossing

Figure 111. Illustration. Actuated control dialog for a mid-block pedestrian phase

Figure 112. Illustration. Reversible freeway lane example

Figure 113. Diagram. TSIS architecture

Figure 114. Illustration. Path file format and example for path following

Figure 115. Illustration. Example of the vehicle file for path following

Figure 116. Illustration. Example of the probe file format for path following

Figure 117. Illustration. Emergency vehicle contra-flow

List of Tables

Table 1. Professional staff and suggested chapters

Table 2. Example milestones and deliverables for a CORSIM study (7)

Table 3. Example problem: key tasks and level of effort estimated

Table 4. Example spreadsheet storage of freeway mainline geometry data

Table 5. Geometric data for CORSIM

Table 6. Demand data for CORSIM

Table 7. Example problem: heavy truck and fleet composition data

Table 8. Sample node numbering scheme.

Table 9. Example problem: geometric inputs with incorrect coding

Table 10. Example problem: southbound HWY 100 at TH 7 westbound exit volumes

Table 11. Wisconsin DOT freeway model calibration targets (14)

Table 12. Example adjustment of the car-following sensitivity factor

Table 13. Example problem: model adjustments for calibrating capacity

Table 14. Example problem: NB HWY 100 AM peak traffic volumes

Table 15. Example problem: final system performance calibration values for NB HWY 100

Table 16. Example nearest neighbor calculation with multiple MOEs

Table 17. Sample MOE summary table

Table 18. Example problem: HWY 100/Minnetonka Blvd. interchange operations in 2031

Table 19. Example problem: northbound HWY 100 freeway operations in 2031

Table 20. Default CORSIM vehicle specifications

Table 21. CORSIM freeway modeling capabilities

Table 22. CORSIM surface street modeling capabilities

Table 23. Bus route MOEs

Table 24. Bus station MOEs

Table 25. Data station MOEs

Table 26. Data station histogram MOEs

Table 27. Freeway detector MOEs

Table 28. Surface street detector MOEs

Table 29. Entry link MOEs

Table 30. Link fleet MOEs

Table 31. Freeway lane MOEs

Table 32. Freeway HOV lane MOEs (continued)

Table 33. Surface street lane MOEs

Table 34. Freeway link MOEs (continued)

Table 35. Surface street link MOEs (continued)

Table 36. Network-wide MOEs

Table 37. Freeway network MOEs

Table 38. Surface street network MOEs (continued)

Table 39. Section MOEs

Table 41. Freeway network vehicle type MOEs

Table 42. Surface street network vehicle type MOEs

Table 43. Conflict data MOEs

Table 44. Permissive periods