Many of the devices we interact with on a daily basis are currently equipped with wireless connectivity. Soon this will be extended to the vehicles we drive/ride every day. Wirelessly connected vehicles will form a new kind of network that will enable a wide set of innovative applications ranging from enhanced safety to entertainment. To efficiently design and develop these applications it is fundamental to thoroughly understand the basic characteristics of this new type of network. In fact, vehicular networks present unique design challenges such as extremely large number of nodes, high mobility, and very uneven node density. In this thesis we initially present the basic properties of this new kind of network by analyzing signal propagation in urban environment and vehicular mobility. We then present how the knowledge of these basic properties can be applied to the design of routing protocols specific to vehicular networks. Next, we present an innovative set of tools for the experimental evaluation of vehicular networks. Finally, we provide a proof of concept for a set of applications enabled by these new networks. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]