Microsimulation Models

Microsimulation (or microscopic) traffic simulation models use a detailed description of the movement of each individual vehicle in order to model traffic at a very detailed level. Microsimulation software is often used to evaluate traffic information, management, and control systems. Microsimulation models represent all related systems that affect traffic, such as traffic control and traffic guidance. Traffic control includes fixed and actuated traffic signals, ramp metering, and restricted access lanes and facilities.

In order to model the response of the drivers to information, microsimulation models provide facilities to represent information dissemination devices, such as variable message signs, and models to capture the response of the drivers to the presented information. As microsimulation models act as the test-beds for intelligent transportation systems and in-vehicle technologies prior to their deployment, microsimulation models sometimes also include facilities to model such systems as advanced driver assistance systems (ADAS), vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) systems, and pricing strategies.

Different types of vehicles are also modeled, including passenger cars, commercial vehicles, powered-two-wheelers, public transport vehicles, and emergency vehicles, as well as different types of drivers. Modeling of pedestrians is a more difficult challenge, but most commercial microsimulation software has begun integrating detailed pedestrian simulation components. The ultimate goal is to [Page 915]model interaction among all of the various modes, such as how buses and trams interact with passenger vehicles, or how all motorized vehicle modes interact with pedestrians and bicyclists.

Microsimulation models have been developed for more than 60 years, and a large number of mature microscopic models are widely used today, including commercial software such as AIMSUN, PARAMICS, TransModeler, and VISSIM; software supported by authorities, such as CORSIM, and academic- and research-oriented software, such as DRACULA, MITSIMLab, and sumo. One of the key prerequisites of microsimulation models is their detailed network representation. The information that is required when representing a traffic network for a microsimulation model is much more detailed than it would be for a less detailed model, such as a mesoscopic or macroscopic model. Typically, besides links, nodes and lanes, the information that is required includes lane connections, turning movements, and location and settings of traffic control devices.