SwashSim Overview

From SwashSim

SwashSim is a traffic micro-simulation tool, intended for both research and education applications, that employs state-of-the-art software architecture. This architecture is object-oriented and built on the C# / .NET framework programming model, which allows for a high level of extensibility and modularity. The new architecture also supports a high level of fidelity with respect to temporal and spatial modeling resolution. SwashSim uses a 0.1-second simulation time step. Currently, SwashSim includes the following modeling elements:

  • Car-following model: Modified Pitt (an extension of the Pitt model used in CORSIM ). Details on these models can be found at Car Following;
  • Lane-changing model (mandatory, discretionary): largely based on CORSIM models. Details on these models can be found at Lane Changing;
  • Gap acceptance model: based on the models used in CORSIM but correlated to driver type. Details on these models can be found at Gap Acceptance;
  • Two-lane highway passing behavior: based on the models implemented in CORSIM. Details on these models can be found at Two-Lane Highway Passing;
  • Vehicle dynamics: utilizes powertrain characteristics of vehicles (engine, transmission) and resistance forces (aerodynamic, rolling, grade) to determine maximum acceleration capability. Details on these models can be found at Maximum Acceleration;
  • Vehicle characteristics: includes 14 different vehicles by default (such as a low-performance Honda Accord, a higher-performance Chevy Impala, a Ford 150 pickup truck, a Chevy Blazer SUV, and a tractor+semi-trailer combination), with the ability to include more. The full list of included vehicles can be found at Vehicles;
  • Driver characteristics: contains 10 driver types by default (type 1-the most conservative driver, type 10-the most aggressive driver); treating drivers as distinct objects (i.e., driver characteristics are not embedded with vehicle characteristics), consequently enabling the user to separately customize vehicle and driver characteristics. Driver details can be found at Drivers;
  • Signal control modes: pretimed and actuated signal control. The signal controller architecture replicates the standard NEMA ring and barrier architecture. Details on signal control can be found at Traffic Signal Operations;
  • Ramp metering: able to run three traffic-responsive ramp-metering algorithms: ALINEA, Fuzzy logic, and demand/capacity, in addition to pretimed control. Details on these algorithms can be found at Ramp Metering; and
  • Route assignment method: randomly assigning a turning movement for the next link based on user-specified turning percentages for the link. Using an origin-destination (O-D) demand matrix with user equilibrium traffic assignment is under development. Details on these models can be found at Route Assignment.