A method of predicting severity of a potential collision of first and second vehicles. The method includes determining that a probability of a potential collision of the vehicles is greater than a threshold value. Vehicle condition-defining signals are exchanged between the vehicles when the probability of the potential collision is greater than the threshold value including a first vehicle condition-defining signal developed on board the first vehicle and a second vehicle condition-defining signal developed onboard the second vehicle. The method further includes predicting onboard the first vehicle a severity of the potential collision for the first vehicle based upon input that includes the first vehicle condition-defining signal and the second vehicle condition-defining signal. A severity of the potential collision for the second vehicle is predicted onboard the second vehicle based upon the second vehicle condition-defining signal and the first vehicle condition-defining signal.