Vehicular Ad Hoc Networks (VANET) is a subclass of Mobile ad hoc networks which provides a distinguished approach for Intelligent Transport System (ITS). VANET’s provide communication between vehicles moving on the roads. Congestion detection and control in VANET is essential and necessary for smart ITS in order to avert an accident. Special considerations are required to develop more sophisticated techniques to avoid and detect congestion. The constrained resources of the Wireless Sensor Networks (WSN) must be considered while devising such technique to achieve the maximum throughput. In this paper we have implemented congestion detection in a collision avoidance scenario in two routing protocols, AODV and DYMO, on the basis of sent and received beacons and packets dropped while nodes communicate with each other or the Base Stations. This paper also discusses and compares the advantages/disadvantages of AODV and DYMO based on battery usage, energy used in transmit mode, throughput, message received and sent. The various ways of congestion control are further discussed.