TSIS-CORSIM™ > Summary
Streets Editor
Based on the Urban Streets module from HCS, this new editor uses basic volume and timing data from the user to automatically construct complex simulation networks within seconds.

High Occupancy Toll (HOT) Lanes
The new version of CORSIM supports different HOT lane pricing algorithms, monetary value of time for each vehicle type, HOT pricing output data, and specification of vehicle types permitted to use HOT lanes in each time period. In addition, the user can specify a percentage of transponders for each vehicle type, and numerous calibration parameters to customize vehicle behaviors near HOT lanes. Sample input files for HOT lanes are automatically installed to the “TSIS Projects” folder. Documentation for this feature is available in “Managed Lanes.pdf”, and in the CORSIM Reference Manual.

Advanced Toll Plazas
CORSIM now supports different types of toll payment in each lane, vehicle type restrictions in each lane, and the percentage of vehicles using each payment type. In addition, the toll plazas now allow all settings to vary between time periods, and numerous calibration parameters to customize vehicle behaviors near toll plazas. TRAFVU 6.3 has been modified to indicate advanced toll plazas, and provides color coding to indicate payment types for each vehicle. Sample input files for advanced toll plazas are automatically installed to the “TSIS Projects” folder. Documentation for this feature is provided in the CORSIM Reference Manual.

Interactive Lane Alignment in TSIS Next
TSIS Next users can now drag-and-drop entire roadway sections to achieve better upstream/downstream lane alignment. Endpoints are used to control intersection and node alignments, and the midpoints are still available to affect curvature. Alternatively, a pop-up dialog is available to manually enter the X/Y feature point values. This feature is used to make vehicle animation and roadway displays more accurate in TSIS Next, but does not affect vehicle animation and roadway displays in TRAFVU.

Adaptive Cruise Control (ACC)
CORSIM now allows the user to specify the percentage of advanced technology vehicles in the traffic stream, plus car-following time headways for each ACC driver type.

New Input Screens in TSIS Next
TSIS Next has been updated for version 6.3; with added support for ACC, HOT lanes, and advanced toll plazas.

Increased Number of Lanes allowed at Interface Nodes

Minor Improvements and Bug Fixes
Fixed the control delay calculation on entry links in NETSIM; fixed a problem with freeways that split into two branches and then rejoin downstream; improved some of the input error checking logic; updated the CSV output format to handle 9-lane approaches; corrected a bug in spillback checking that occurred when the right receiving link and the right-diagonal receiving link were the same link and a single lane served both right and right-diagonal turns; fixed a problem in the calculation of travel times and average speeds on NETSIM interface links; auxiliary lanes can now be included on FRESIM interface links.

Signal Pre-emption for Actuated Controllers
The previous version of CORSIM could only handle pre-emption for pre-timed controllers. Sample input files for both pre-timed and actuated signal pre-emption are automatically installed to the “TSIS Projects” folder.

Traffic Assignment (TA) for Actuated Controllers
The previous version of CORSIM could only handle TA for pre-timed controllers.

Two-Lane Rural Highways with Passing and No-Passing Zones
Added the ability to pass a vehicle by temporarily moving into the opposing traffic stream on a two-lane highway. A new input field was added to Record Type (RT) 20, and brand-new RTs 154 and 155 were added. TRAFVU 6.2 has been modified to animate two-lane highways. TSIS Next 6.2 has been updated to support input data for two-lane highways. Sample input files for two-lane highways are automatically installed to the “TSIS Projects” folder.

Vehicle Type Origin-Destination (O-D) Volumes in FRESIM
The previous version allowed vehicle type multipliers for standard off-ramp volumes (RT 25), but automatically applied O-D volumes to all vehicle types (RT 74). CORSIM 6.2 now offers RT 75 for coding unique O-D volumes for each vehicle type. RT 74 is still available for cases in which O-D volumes are the same for each vehicle type. TSIS Next has been updated to support the coding of vehicle type O-D volumes.

Animation plus Input Editing in TSIS Next
TSIS Next now combines TShell, TRAFED, and TRAFVU functionality within one application. The visualization feature is “a work in progress”, and does not draw roadways as accurately as TRAFVU. An icon is available for switching between lane drawing mode (like TRAFVU) and the default link-node diagram mode (like TRAFED).

Minor Improvements and Bug Fixes
Corrected the calculation of control delay on external signalized links, corrected lane-selection logic for buses; improved some of the input error checking logic; corrected certain vehicle movement logic near off-ramps; corrected behavior of permissive left-turns or right-turns opposed by a diagonal movement; fixed problems in some of the TSIS Next input dialogs; improved the runtime extension (RTE) to support advanced signal pre-emption; corrected errors in spillback checking; corrected several output processor MOEs; corrected an error in processing a vehicle approaching a lane drop; corrected an error in traffic assignment that caused incorrect path selection; trucks are now allowed to be more aggressive when approaching a lane drop or the end of an acceleration lane; changed the average spacing between queued FRESIM vehicles from 3 feet to 7 feet.

The TSIS 6.1 installation now automatically installs the TSIS Next interface program alongside the original TSIS interface program. Users can choose between launching the original TSIS (TShell) or the new TSIS Next, depending on their needs and preferences.

Modeling Options

  1. CORSIM can now simulate up to nine lanes per intersection approach.
  2. Emergency vehicles can now be simulated, and can cause signal pre-emption if desired.
  3. CORSIM and TRAFVU can now handle left-hand drive networks, with TSIS Next as the preferred input editor.

Simulation Logic
In addition to containing all of the improvements from build 507, build 508 now offers improved simulation logic for spillback checking with diagonal movements, triple turn pocket lanes, discretionary lane changes, buses moving between NETSIM and FRESIM, and setting goal lanes.

Documentation Fixes, Bug Fixes, and Miscellaneous Changes
Information in the HTML Help files was corrected and improved. New documentation for path following and emergency vehicles was added. Certain inputs that could cause crashes in CORSIM before will now cause standard error messages and/or no errors. A confusing TShell warning message for “restricted” Windows users has been eliminated. TRAFED no longer exports record type 49 (actuated timing transition) for single-period files. Brand-new sample networks are now installed on the users computer for demonstrating various CORSIM features. Checkboxes in the output processor, which would cause incorrect results if they were all turned on at once, have been corrected. Improvements and corrections have been made to TSIS Next, which was originally available as a free download. The TSIS 6.1 installation CD contains an updated sample runtime extension (RTE), an updated RTE Developers Guide, and an updated CORSIM Data Dictionary.

Simulation Logic
Version 6.0 now offers improved simulation logic for surface street lane changing, complex intersection modeling, freeway acceleration lanes, deceleration lanes, ramp meters, car-following, and origin-destination modeling.  An enhanced random number generator will produce better distributions, for improved stochastic modeling.

Graphical Input Editor (TRAFED)

  1. Automatically merge two separate networks into one.
  2. Snap to grid so nodes can be placed at even increments.
  3. Change the background color.
  4. Cut, copy, or paste multiple links and nodes at once.
  5. Move selected links and nodes using the arrow keys.
  6. Scroll beyond the edge of the network.

Actuated Control
Actuated controller parameters may now vary from time period to time period to simulate different time-of-day plans. The number of actuated controllers is now dynamic and limited only by the number of nodes in the network. The TRAFED input screens for actuated control have been radically changed to make it easier to specify actuated controllers in CORSIM. 

Output Processor
The Output Processor has been redesigned to efficiently summarize any model result generated by CORSIM. Obtain cumulative MOEs from the start of simulation, or just for the current time interval, or just for the current time period, or any combination of those three.

Vehicle Animation File
The TRAFVU animation module can now process animation files larger than 2 gigabytes. If desired, the user can now ignore any desired set of links during animation, which reduces animation file size.

Modeling Options

  1. CORSIM can now simulate up to eleven through lanes in one direction on a mainline freeway link, i.e., 5 through lanes plus 6 full auxiliary lanes.
  2. The minimum desired free-flow speed on surface streets has been reduced to one mile per hour, to approximate vehicles dwelling in locations such as airport passenger pickup zones.
  3. Truck lane logic was modified to provide exclusive truck lanes in which non-truck vehicles are prohibited.
  4. Sign control can now be active in one time period and removed in the next time period, or vice versa.
  5. The user can now observe vehicles entering the network during the initialization period, if desired.

Measure of Effectiveness (MOE) Data in TRAFVU
TRAFVU now reports interval-specific data in addition to cumulative data. Time interval-specific data is more reflective of conditions at the time shown. TRAFVU and CORSIM now report exactly the same MOE values.

Run-Time Extensions
Run time extensions (RTEs) may now access CORSIM at more than one different processing control points, providing more control to an RTE and allowing a wider variety of extensions to CORSIM. New actuated control API functions enable RTE developers to access critical control parameters and obtain diagnostic state information regarding actuated control.

TRF Manipulator
The TRF Manipulator tool can be used in a script to repeatedly open a CORSIM (*.TRF) input file, manipulate the contents, and save the file with a new name. Well-written scripts can make this tool do much of the previously intensive and error prone task of changing data for experimental research.

TSIS 5.1

Traffic Software Integrated System

In February 2003, version 5.1 was released as a free update, and was shipped automatically to all registered users of version 5.0. TSIS 5.1 now features a new GUI-based traffic network and simulation input editor known as TRAFED. Also, electronic documentation is now provided in HTML format for all TSIS components. This allows placement of the written Users Guides on-line, without having to modify the original documents. The HTML help system uses the Internet browser to provide a powerful, flexible, hypertext-based help utility. Context-sensitive help is still available via the F1 key. Click below to read more about the components of TSIS 5.1.

TRANSYT-7F (sold separately): CORSIM optimization and post-processing

TShell is the TSIS environment’s GUI that integrates the TSIS tools and allows the engineer to effectively manage traffic analysis projects. Version 5.1 introduces the following new features:

  • The Project view now provides the capability of sorting the project tree either by the names of the items on the tree or by the modified dates of the files associated with the tree items.
  • Project View properties can now be specified. These properties include the tree sort parameter and order, whether files deleted via the tree are sent to the recycle bin, and whether TShell displays confirmation dialogs for tree operations.
  • The Output View properties include background color and text font, size, and color.
  • Improved tool management changes include the ability to define and use multiple tools of the same component.
  • The Script Tool provides improved interfaces for better interaction with TShell and for running CORSIM. The Script Tool User’s Guide includes a new, detailed Reference Manual for the functions defined by these new interfaces.
  • TSIS 5.1 includes seven sample Visual Basic scripts that use the new Script Tool interfaces and that demonstrate the new capabilities of the CORSIM component, including multiple runs and extraction of data from output files.


CORSIM includes both NETSIM (for surface street simulation) and FRESIM (for freeway simulation). Version 5.1 of CORSIM offers the following new features:

  • CORSIM now provides its own interface and driver software, separate from TShell.
  • In addition to the user interface, the CORSIM driver provides access to a new output data processor. The output processor enables the user to accumulate user-selected statistics and summary data during multiple runs of CORSIM. It writes the collected data to an Excel workbook, a comma-separated file, and/or a tab separated file.
  • CORSIM can now simulate much larger traffic networks than before.
  • The maximum link length in NETSIM has been increased from 4000 feet to 9999 feet.
  • CORSIM can now run simultaneously on multiple test cases in the same directory.
  • A new flag is available on RT 2 (entry 3, column 16) to force CORSIM to use the maximum initialization time.
  • Logic for determining if a vehicle would join spillback was improved.
  • Control delay is now aggregated over all turn movements in the simulation output table.
  • Anticipatory lane change inputs are now echoed to the output file.
  • Exit interface links can now be specified as destinations on Record Type 74.
  • Error checking has been improved.
  • Numerous software corrections have been implemented.
Version 5.1 of TRAFVU offers the following new features:

  • A directory has been added to the CD that includes the files necessary to view and animate traffic networks using TRAFVU. This directory may be copied by licensed users and distributed to non-licensed individuals for the purpose of viewing networks and animating vehicles, signals, and MOE using files created by a licenced user of the package. The TRAFVU Viewer directory contains a special licence and instructional files for distributing TRAFVU as a Viewer.
  • TRAFVU now displays the bitmap background used by TRAFED. When exporting the TRAFED network to a CORSIM input (.TRF) file, TRAFED writes the bitmap information to the .TRF file. From the Display menu and a corresponding toolbar button, the user can toggle the display of the background bitmap.
  • TRAFVU now displays link names on the network map next to links that have entries on record type 10 in the .TRF file. From the Display menu and a corresponding toolbar button, the user can toggle the display of the link names. Using the Preferences dialog, the user can control the color, size, and placement of the link names on the network map.
  • TRAFVU now maintains application and window settings for a user between TRAFVU sessions. Each user can have different preference settings. Application-level preferences include: dynamic scrolling, tool tip display, and APC window settings (including size and placement). Window-level preferences include: object display button settings, vehicle color and detail properties, background color, link name settings, and window component (toolbar, legend, status bar) display preferences.
  • The user can now control the display of warning and HOV signs using the Warning Sign item on the Display menu or the corresponding toolbar button.
  • It is now possible to right click on an entry link to display its attributes, e.g., entry volume.
  • The Zoom Capture and Set dialog have been modified to allow specifying a file to which window coordinates are saved or from which they are retrieved. This allows the user to save multiple sets of coordinates for a single or multiple cases.
  • TRAFVU can now load cases (.TRF files) from write-protected directories/drives and from CD-ROM.
  • Logic has been added to control whether links are animated above or below intersections.


TRAFED is a new product distributed as part of the TSIS5 package. TRAFED is not sold separately – purchasers of TSIS5 receive TRAFED automatically. The ITRAF input editor commonly used in conjunction with TSIS4 has been updated and is also available, but must be purchased separately. Users who are comfortable with TRAFED do not need to purchase ITRAF.

TRAFED allows easy creation and editing of CORSIM traffic networks. Some of the new features within TRAFED version 5.1 are highlighted below:

  • Range checking and default settings have been improved.
  • The user can now scroll past the edge of the existing network using the scroll buttons.
  • A new distance-measuring tool has been added to the toolbar, allowing the user to easily check the scale of a bitmap image.
  • The bitmap may be turned on and off with a button on the toolbar.
  • The TRF file can be sorted during export so that most of the records are sorted by their first two fields.
  • Link splitting has been improved and no longer resets the signal controllers.
  • Numerous bugs have been fixed.
  • Turning volumes present in the TRF file are now preserved during translation to TNO file format.