Driver-based adaptation of Vehicular Ad Hoc Networks for design of active safety systems This paper studies the need for individualizing vehicular communications in order to improve collision warning systems for a highway scenario. By relating the traffic-based and communications studies, we aim at reducing highway traffic accidents. To the best of our knowledge, this is the first paper that shows how to customize vehicular communications to driver’s characteristics and traffic information. We propose to develop VANET protocols that selectively identify crash relevant information and customize the communications of that information based on each driver’s assigned safety index. In this paper, first, we derive the packet success probability by accounting for multiuser interference, path loss, and fading. Then, by Monte carlo simulations, we demonstrate how appropriate channel access probabilities that satisfy the delay requirements of the safety application result in noticeable performance enhancement.