Trafikmodeller

Trafikmodeller are mathematical representations of road networks, traveler behavior, and traffic dynamics used to analyze, predict, and manage transport systems. They span scales from individual vehicles to entire networks and are used to study how changes in infrastructure, policies, or conditions affect performance.

Macroscopic models treat traffic as a continuous flow described by variables such as density, flow, and average speed. Classic examples include the Lighthill-Whitham-Richards model. Mesoscopic models blend aggregate flow with some discrete vehicle dynamics, while microscopic models simulate individual vehicles and driver behavior, using car-following rules such as the Gipps model or the Intelligent Driver Model. Network models address routing and assignment, often employing Wardrop equilibrium and dynamic traffic assignment to predict route choices and congestion over time.

Data and calibration are central to model development. Sources include traffic counts, loop detectors, cameras, GPS, and probe data. Models must be calibrated and validated against observed data, and sensitivity analyses are used to assess reliability and uncertainty.

Applications of Trafikmodeller include urban and regional planning, traffic management and control (such as signal timing and ramp metering), incident analysis, travel-time prediction, and policy evaluation (infrastructure investments, pricing, or demand management). They also support environmental impact assessments and resilience planning.

Common tools and software packages cover both open-source and commercial options, such as SUMO, VISSIM, AIMSUN, MATSim, and TRANUS. Model selection depends on the purpose, data availability, network size, and required level of detail, balancing accuracy with computational resources.