This document summarizes and compares several existing broadcasting protocols for vehicular ad hoc networks (VANETs). It discusses the need for reliable broadcasting in VANETs to support safety applications. Simple flooding is not effective due to collisions in dense areas. The document reviews probabilistic, counter-based, distance-based, and location-based broadcasting schemes. It also discusses neighbor knowledge methods. None of the existing schemes are optimal for all situations. The document aims to propose a new intelligent broadcasting technique for emergency messages in VANETs to improve message reception reliability and availability.