Enhanced threat assessment

A computer includes a processor and a memory, the memory storing instructions executable by the processor to, in a host vehicle, determine a threat number for a first target vehicle based on data received from the first target vehicle indicating at least one of a position, speed, or route history of the first target vehicle, identify a second target vehicle based on data collected with one or more host vehicle sensors when the threat number of the first target vehicle exceeds a threshold, determine that the first target vehicle and the second target vehicle are not a same vehicle, and, then, upon determining that the first target vehicle and the second target vehicle are not the same vehicle and that at least one of (a) a barrier is detected between the host vehicle and the first target vehicle or (b) that a threat number of the second target vehicle exceeds a second threshold, suppress a collision avoidance action.