Implementation of the Revised Safety Impact Methodology Tool

The Safety Impact Methodology (SIM) software tool is a suite of simulation modules designed to assess the safety effectiveness of crash avoidance systems based on cooperative vehicle-to-vehicle (V2V) communications and/or vehicle-based sensors such as radar. The tool uses a Monte Carlo simulation approach to estimate reductions in crashes and crash severity for specific pre-crash scenario types. The output of the SIM tool can be combined with external data on exposure and occupant injury to support analysis of overall harm reduction. The SIM tool uses an incremental time-step approach to model linear motion, turning movements, driver reactions, and warnings/actions from the crash avoidance system. Each module configures the simulation engine to address a specific type of pre-crash scenario, with a wide array of user-configurable parameters. The SIM tool implements pre-crash scenarios that are addressed by the V2V-based forward crash warning, intersection movement assist, left turn assist, blind spot/lane change warning, do not pass warning, and emergency electronic brake light safety applications. The tool also has the capability to simulate other priority pre-crash scenarios and applicable safely applications, such as drifting into opposite direction travel lanes. This report details the mathematical and computational basis for the SIM tool, including assumptions, theory of operation, kinematic equations, and detailed specifications of pre-crash scenarios.