Aimsun Live is a traffic forecasting solution based on simulation, developed and marketed by Aimsun.
Traffic control centers use Aimsun Live (formerly Aimsun Online) to make real-time decisions about the management of a road network. It is used to dynamically forecast future traffic conditions based on the current state of the network and to evaluate incident response or traffic management strategies.
Aimsun Live connects with the traffic control center, continuously processing live field data. By combining these live traffic data feeds and high-speed simulations with the emulation of congestion mitigation strategies, Aimsun Live can accurately forecast the future network flow patterns that will result from a particular traffic management or information provision strategy. From a single highway corridor to an entire major city, Aimsun Live can simulate vehicle movement within the road network.
Aimsun Live was launched in 2008 and is now fully deployed on Interstate 15 in San Diego, Grand Lyon in France, and other locations worldwide.
Features
Aimsun Live uses live traffic data feeds and simulations to forecast future traffic conditions for large Urban areas and regional networks.
Real-time analysis
Aimsun Live analyzes real-time inputs from disparate sources of information, such as field traffic controllers, detectors, incident reports and live data feeds from key intersections.
Calibrated model retrieval
Using up-to-date field data, Aimsun Live identifies, retrieves, and loads a travel demand matrix for the road network being managed. It finds the closest match between the data received in real time and several demand patterns stored in a database. The demand pattern database is created in a prior step by carrying out an analysis of historical data.
Real-time simulation
This step involves the dynamic (mesoscopic or microscopic) simulation of one or more scenarios in real time. Each scenario is simulated on a dedicated computer. The simulations produce dynamic forecasts of traffic conditions at a detailed, local level for the next 30–60 minutes. Each simulation considers a concrete set of actions that might be applied in order to improve the network situation. One of the scenarios always corresponds to the ‘do nothing' case.
The area included in the simulation model depends on the type of network being managed. It is typically defined using equilibrium assignment techniques, which evaluate at a high level the impact of local but significant capacity changes on the rest of the network. The objective is to exclude areas that are unlikely to be affected by incidents or responses to those incidents.
Simulations typically last 1–3 minutes depending on hardware specifications, network size and level of congestion (number of vehicles). These simulations are run in 'batch mode' (without animation in 2D or 3D) in order to improve performance.
Online visualisation
Response information is presented visually online to provide support for operational decision making. Traffic control operators are provided with quick snapshots of predicted traffic flow and performance indicators for different control alternatives.
Other features
Customization to work with traffic control software
Assimilation of new data to improve the quality of predictions over time
Practical uses
Online travel information systems
Dynamic emergency vehicle routing
Emissions management
Accident response strategy assessments
Urban and interurban congestion management
Security threat mitigation and large-scale evacuation management
Project examples
Aimsun Live is or has been used to inform operational decisions for: