Performance Metrics
The study of performance metrics considers all these factors and determines performance measures and recommendations of collision avoidance systems as they are affected by several considerations.  Some of them are vehicle related and the others driver dependent as illustrated in Figure 1.2.  Most of the vehicle variables have a wide operating range with significant differences especially in certain operating regions.  This leads to either defining performance metrics as dependent on specific technologies or design methodology, or combination of all technologies/vehicle implementations.  Figure 1.2 does not show the system delay that is defined as the time required to acquire the information external and internal to the vehicle, process the data, and execute algorithms to determine the action as defined in Figure 1.1.  Normally, this delay is much shorter compared to overall delays in the system.