This article surveys protocols and applications for the driving safety and efficiency in vehicular sensor networks. Nowadays, most vehicles are equipped with Global Positioning System navigation systems in the form of a dedicated navigator or smartphone app. Also, the government regulation requires vehicles to be equipped with dedicated shortrange communication device for the communications among vehicles or between vehicles and infrastructure for a safety purpose. Because of this trend, many applications in vehicular networks can be envisioned for the safety of drivers and pedestrians as well as driving efficiency and fuel saving. To support these applications, protocols in physical, link, and network layers are designed and tailored for the optimal performance. This article summarizes and analyzes the state-of-art articles in the protocols and applications for vehicular sensor networks in order to shed the light of research direction on the audience in vehicular sensor networks.