Spatio-temporal variations of vehicle traffic in VANETs

Via statistical analysis of several sets of empirical data collected from realistic scenarios, we realize that exponential model is a good fit for highway vehicle traffic. This model provides a single parameter (the exponent of vehicle density λs) to describe traffic variation. We reveal that highway traffic drastically varies over time (of different scales), across geographic locations and over technology adoption phases. Considering multi-hop geocast and single-hop broadcast, we show via both mathematical analysis and simulations the performance of path availability in the former, and packet delivery ratio in the latter, with respect to short- and long-term traffic variation.