With recent technological advances made in the field of vehicular communications, a plethora of applications has emerged that aim to improve driver safety and traffic fluidity. The platooning application is expected to be a good first step to tame autonomous driving, especially traffic congestion problems in big cities. In this context, it is important to study a platoon of vehicles in its environment, sharing the road and wireless channel with other road users. For such a scenario, efficient simulation tools come in handy for studying vehicular communications in large scale environments. This paper presents a step toward improving iTETRIS simulation platform to simulate platoon communications in large-scale connected vehicles use case. To this end, a restricted communication zone, centered around the leading vehicle of the platoon, and in which vehicles can receive and send packets is introduced to limit the computational cost of communication simulation. The merits of the improved platform in term of time execution efficiency compared to iTETRIS are shown through extensive simulation using real mobility traces.