Plugins/Add-ons Development

We provide services on the development of plugins or add-ons for modeling software including Paramics, TransModeler and Vissim and TransCAD. We are the major microsimulation (including Paramics, TransModeler, and Vissim) plugin developer in the world.  Our plugins are used by many consultants, universities, and governments.

San Diego experiences significant traffic congestion during peak travel periods, has limited HOV and HOT lanes, and has limited transit capacity. A potential solution is to increase multi-jurisdictional and multi-agency collaboration on corridor management. The San Diego I-15 corridor was chosen as a site for Analysis, Modeling and Simulation (AMS) of Integrated Corridor Management (ICM) strategies. One strategy was to use this coordinated ramp metering control plugin.

CLR Analytics developed the San Diego Ramp Metering System (SDRMS) plugin for the TransModeler software, in collaboration with Caliper, the developer of TransModeler, and Cambridge Systematics. CLR Analytics reversed engineered the SDRMS control logic being used in the field and then implemented it in Transmodeler as a plugin. The plugin allows for all features of the SDRMS algorithm to be utilized including: Rate plans per signal, AM and PM timing plans, and TOD plans. This allows traffic engineers and modelers to simulate the same ramp metering control currently being used in the field and further test different settings. SDRMS is the most widely used ramp metering system in California. It is currently deployed in Sacramento, Fresno, San Bernardino, Riverside, and San Diego areas. SDRMS can be operated under traffic-responsive or pre-timed metering control. Time-of-day (TOD) table needs to be set in order to associate a time period with the control code.

Engineers in CLR Analytics have accumulated profound actuated signal control knowledge through various academic and practical projects. We developed several versions of actuated signal control plugins under Paramics during the last decade. The collaboration between Quadstone Paramics and CLR Analytics allowed Paramics to have an actuated signal control module that meets the expectation from modelers and traffic engineers. In this effort, CLR Analytics provided the NEMA and 170/2070 control logic and some preliminary GUI design to Quadstone Paramics for the development of the actuated signal control module. CLR Analytics also helped test to make sure the logic was implemented correctly.

In this project, CLR Analytics developed the Lane Management plugin for the Paramics software based on the design from DKS.

We also provided supports to the DKS team on:

  • how to use various plugins developed by CLR Analytics
  • on-call simulation modeling questions
  • a ramp metering scenario testing run


The plugin upgrade involved the use of new API functions to replace old API functions, logic and functionality checking, and the addition of some basic graphical interface.  In addition, CLR Analytics also developed one new plugin from scratch: Truck Behavior Plugin. The plugin basically provides a modeling solution to the common facts about truck behaviors that were not included in the Paramics software.


Traffic Operation System (TOS) is the current ramp metering system deployed in Bay area, California. Under this project, CLR Analytics upgraded the TOS ramp metering plugin from Paramics version 4 to version 6.0. The metering control logic and queue override strategy were further checked for correctness. Some Paramics UI was also added to the plugin for users to see ramp metering locations through Paramics graphical interface.

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