Vehicular ad hoc network as an intelligent transportation system supports traffic management to facilitate navigation, safety, and services to end-users. Delivery of safety messages is prioritized to avoid hazards in the system. In this regard, this paper discusses the existing TDMA MAC protocols in vehicular ad hoc networks that efficiently coordinate and communicate with the vehicles and minimize the message collision. Vehicular movement and traffic density lead to link failures, collisions, and load imbalance in the network. MAC protocols with dynamic time slot synchronization, message priority, bandwidth, and frequency management techniques ensure safe message delivery, hazard prevention, and low message collision rates in VANETs. This article provides the classification of TDMA MAC protocols for distributed, centralized and hybrid protocols. Various types of collisions, two-way traffic load, multi-channel utilization, and access challenges are discussed in detail. Further, the working mechanism and performance attributes of TDMA MAC protocols are explained.