This work presents a fuzzy logic-based highway on-ramp control (HORC) approach that works by controlling the traffic lights at the on-ramp to facilitate the flow of traffic onto the highway. The proposed HORC comprises a fuzzy logic system and a decision-making model. The former determines the switching probability of the traffic light, while the latter makes the decision concerning the switching of the traffic light. The HORC requires only the velocities and the difference of velocities of the vehicles that are entering the highway. Simulation results indicate that the proposed HORC outperforms pre-timed ramp control.