Over the last few years, vehicular adhoc networks have been playing a vital role in many researches around the world, in which intelligent transport systems is a major area. This paper addresses the issues concerning the vehicular traffic congestion. The paper provides a review on two congestion mechanisms, adaptive position update (APU) and distributed fair transmit power adjustment in VANET (D-FPAV). APU is a strategy in which it dynamically adjusts the frequency of position updates based on the mobility dynamics of the nodes and the forwarding patterns in the network. D-FPAV controls congestion by adjusting the node transmission power, where the nodes transmit power setting depends on predictions of application-layer traffic and the observed number of vehicles in the surrounding. The paper includes a simulation of a normal VANET setup without congestion and a VANET setup with APU and D-FPAV employed with results proving the latter reduces the time delay caused due to traffic congestion. Copyright © 2018 Inderscience Enterprises Ltd.