# A Comparative Study on Traffic Modeling Techniques for Predicting and Simulating Traffic Behavior
## 5 Traffic Simulation Models
### Traffic Simulation Tools
It is capable of simulating traffic at the microscopic level and simulates moving vehicles and accidents [84]. In this simulator, the vehicle width is fixed, and it does not take into account the different types of vehicles such as buses, light rail, heavy rail, and trucks [54; 77]. SUMO is designed as an intermodal traffic-based simulator that includes public transportation, traffic road networks, and users such as pedestrians. SUMO simulators encompass a number of built-in features which include C2X communication among vehicles that are achieved through the integration of SUMO simulators with network simulators (such as OMNeT++ or ns-3), multi-modal traffic, and automated driving. Traffic management is also an additional add-on feature that can model vehicle detection loops and video detectors to manage and control traffic through traffic lights, monitoring vehicles' behaviors and adjusting traffic parameters such as vehicles' speed limits [58; 85]. * CORridor SIMulation (CORSIM) [86] is known as one of the most widely used microscopic traffic simulator software programs worldwide. CORSIM is used in thousands of applications as a standard traffic simulation tool. CORSIM is equipped with reliable validation, continuous logic enhancement, solid verification, and calibration efforts. It can produce real-world traffic flow realistically and with high accuracy. All types of geometric conditions including complicated traffic scenarios can be handled virtually by CORSIM. Some of these conditions include the surfaces of streets that have different combinations of turning pockets and lanes, different types of on and off-ramps, and multi-lane freeway segments. * Paramics addresses road networks with drivers and simulates the decisions, intentions, and subsequent actions of drivers when they move toward their destinations [87]. Depending on the characteristics of the basic network and the probability of encountering traffic congestion, drivers are considered to choose the possible route in the simulator. A set of decisions is prioritized by each driver throughout the network. These decisions include traffic speed and specific moments to change, cross, or merge into different traffic lanes. In the Paramics simulator, the network topology and travel demand drive the calibration. Flows of saturation and the proportion of lane usage are generated as outputs from the simulator to examine the road network's performance. However, these parameters cannot be provided as input for calibration assistance. Although Paramics does not prescribe the effect of a traffic model, it can simulate and model the cause of action. This way, the simulator preserves the predictive power of the simulation process in subsequent changes in the model and tests the change in the traffic road network. * The TRansportation ANalysis and SIMulation System (TRANSIMS) creates an integrated regional transportation system environment by employing advanced computational and analytical techniques [88]. The simulation environment includes a regional population of individual travelers. TRANSIMS simulates the activities and individual interactions of travelers and their plans for the transportation system. It also simulates and determines the environmental impact of these activities. TRANSIMS contains an interim operational capability (IOC) with numerous features, applicability, and readiness for each major module to complete different types of specific traffic case studies.