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Multi-hop vehicle-to-vehicle communication is useful for supporting many vehicular appli-cations that provide drivers with safety and convenience. Developing multi-hop communication in vehicular ad hoc networks (VANETs) is a challenging problem due to the rapidly changing topology and frequent network disconnections, which cause failure or inefficiency in traditional ad hoc routing protocols. We propose an adaptive connectivity aware routing (ACAR) proto-col that addresses these problems by adaptively selecting an optimal route with the best network connectivity-quality (CQ) based on statistical and real-time density data that are gathered through an on-the-fly density collection process. The CQ metric models the joint probability that a network is connected and a packet is successfully delivered in this network. The protocol consists of two parts: 1) select an optimal route, consisting of road segments, with the best CQ, and 2) in each road segment of the chosen route, select the most efficient multi-hop path that will improve the deliv-ery ratio and throughput. The optimal route is selected using our connectivity-quality metric that takes into account vehicles densities and traffic light periods to estimate the probability of network connectivity and data delivery ratio for transmitting packets. Our simulation results show that th