This page within Virginia Tort Case Law is a compilation of matters reported and summarized by Brien Roche dealing with the topic of Taxicabs.
Taxicabs are considered common carriers. Taxicabs are some times known as hacks and the operators are called hackers. Most cabs are regulated by the locality and subject to special licensing laws and regulations as far as fees and operation.
See Va. Code § 46.2-2061 stating this article does not make taxicab operators common carriers.
For more information on taxicabs see the pages on Wikipedia.