Which best describes the role of a traffic simulation model in traffic engineering?

The role of a traffic simulation model in traffic engineering is primarily to visualize the impact of various traffic control changes. These models allow engineers to create virtual environments where different scenarios can be tested, helping to analyze how modifications in traffic signals, lane configurations, or other traffic control measures affect traffic flow and safety. By simulating various conditions and interventions, engineers can identify potential issues before actual implementation, leading to more effective traffic management solutions and enhanced understanding of traffic dynamics.

The other choices do not capture the primary purpose of a traffic simulation model. While managing traffic signal hardware, optimizing public transport schedules, and assisting in criminal investigations may involve data handling or simulation in a broader context, they do not specifically address the core functionality of simulation models in visualizing and predicting traffic behaviors under different scenarios.