It is de facto that merging two different streams of vehicles into one single stream poses some degree of inconvenience. As human lives are at stake, a lot of care has to be taken in this area of traffic management. In this paper a proactive merging strategy is proposed, keeping the intersection of ramp and a highway as the main focus. In our algorithm, it is assumed that the vehicles are sensor-enabled, with which they can communicate their position, velocity, acceleration and other dynamic attributes as needed by micro-electro-mechanical systems(MEMS), to each other. By doing so they can decide amongst themselves the order of merging at a safe distance well before the intersection. A sliding- window is used to monitor the vehicles on the main road as well as the ramp. For the vehicles in the window we consider the time they take to merge with minimum deceleration. We logically order them for merging into one single stream. Our experiments demonstrate that Sliding-Window Proactive strategy increases the traffic throughput on highways and decreases the delay.