typical conditions in which driver aggression can be allowed to reach detrimental levels. The environmental influences mentioned above, heat and noise, may well exert the most influence in congestion, and a sense of overcrowding is certainly most likely to arise there. Individual differences and the car as an annex of the home Individual differences in our predisposition to be aggressive may be important in the driving experience in deciding the outcome of conflict. The extent to which the vehicle symbolizes real and imagined aspects of the driver's individuality has already been outlined; the car is an indication, to both the driver himself and those around him, of social standing, of wealth, of attitude, and of ersonality. But when a situation of conflict arises, individual differences may again be of singular importance. Any form of attack is a reliable and potent stimulus for aggression, particularly when the "victim perceives the event to be wholly deliberate and indicative of malicious intent. If this is not the case, i.e., if the individual decides on balance that the conflict arose from error and misjudgment, as is frequently the case on the road, the extent to which aggression is used in retaliation is probably determine to a greater extent by individual predispositions. The problem of feedback in the driving environment is again important; if it is relatively difficult to communicate to another driver that an unfortunate maneuver was the result of a mistake on your part, his decision as to whether or not your action