Collision-warning system

A collision-warning system for a motor vehicle is provided. The collision-warning system includes a controller (34 in Figure 1) includes a processor and a memory storing processor-executable instructions in a host vehicle 30. The processor 34 is programmed to designate a target vehicle 32 as a collision risk upon determining that an intersection angle β between the host vehicle 30 and the target vehicle 32 is between preset lower and upper bounds and an absolute value of an azimuth angle rate of change dθ/dt of the host vehicle 30 s below a preset threshold. The controller 34 allows the host vehicle 30 to determine whether the target vehicle 32 is a collision risk and, if warranted, perform evasive maneuvers or warn a driver of the collision risk. By relying on the intersection angle β and the azimuth angle rate of change dθ/dt, the controller 34 determines collision risk in a computationally efficient manner with a low amount of error and measurement noise. The computational efficiency may allow more frequent updating and thus more accurate tracking of the target vehicle 32.