CORSIM

Microscopic Traffic Simulation Model

Version 5.0 of CORSIM offers the following new features:

• Freeway HOV Operations. This feature, which was introduced in Version 4.32, has been finalized. Included are new inputs to specify what percentage of HOVs will use the HOV facility (Record Types 33 and 70) and a new input to specify where HOV vehicles begin to react to an off-ramp (Record Type 20). HOV lanes are now allowed on interface links.
• Control Delay MOE. This MOE was added for surface-street intersections and can be used to calculate the Level of Service of an intersection or intersection approach using the HCM method.
• NETSIM Vehicle Type Specific Multipliers for Surface Street Turn Movements. This is the NETSIM equivalent of the FRESIM feature introduced in version 4.32. It allows users to apply different turn percentages to different vehicle types, such as trucks. NETSIM and FRESIM both use Record Type 24 for this feature.

In addition to these new features, CORSIM 5.0 includes enhancements and fixes to previously identified problems such as:

• Record Type 147 can now be used in FRESIM to specify the distribution of free flow speed based on driver type. It previously could only be used in NETSIM.
• Detectors are now allowed on interface links.
• Any configuration involving stop sign control can be modeled. Previously, some configurations involving stop sign control were not modeled correctly. Logic was also improved to model configurations involving both stop sign and yield sign control.
• The probability of joining spillback, entered on Record Type 141, now also applies to left turning vehicles. It previously applied to through vehicles only.
• The maximum number of FRESIM detectors was increased from 300 to 600. The maximum number of FRESIM detector stations was increased from 70 to 200.
• Many existing features were significantly improved. Errors in FRESIM collision avoidance, destination assignment and leader determination were eliminated. Changes were made to the logic that deals with vehicles crossing interface nodes to improve the car following between networks. Errors in processing truck restriction lanes were corrected. An error in the way vehicle counts on Record Type 53 were converted into entry volumes was corrected.
• FRESIM uses an iterative process to solve a set of equations to assign origin-destination percentages based on inputs from Record Types 25, 26 and 74. Record Type 74 now includes an input for overriding the default value of the criteria for determining that the solution of the gravity model has been reached.

Finally, the following items were changed from version 4.32:

• FRESIM Record Type 24 was modified. The specified link must be a mainline link. In version 4.32 the specified link was an off-ramp link. This was done to make it more compatible with the way it is used in a NETSIM network.
• The change to the NETSIM lane channelization code zero that was introduced in CORSIM 4.32 was removed. A blank or zero channelization works as it did in version 4.2 and earlier.