In this work, the controllability problem of the main road with one on-ramp segment is investigated in the free-way traffic flow. In this regard, finite dimensional nonlinear model is designed through coordinations of variable speed limit (VSL) and ramp metering (RM) where the controllability property of the system is derived under continuous VSL and RM controllers. This fact enables us to control the density of the main-line as well as to decrease the queue density of the merging sector at any given time. Hence, the main achievement of this work is to maintain the flow of the mainstream with one on-ramp section by simply controlling the density of the main road segment for a given time while taking into account the queue density of the on-ramp section.