The issue of connectivity in Vehicular Ad-hoc Network (VANET) is influenced by the diverse characteristics of traffic flow on the road. We have applied fluid dynamic model and captured the connectivity dynamics considering microscopic aspects in heterogeneous traffic flow in a signalized urban road environment. The applied model incorporates jamming density that take into account the effect of safety distance and vehicle front density on velocity. The variation in arriving ratio and safety distance between different types of vehicles creates impact on the connectivity dynamics. This density estimation provides more realistic data about road conditions and helps to gain improved connectivity conditions under different type of vehicles for vehicular ad- hoc network.