Traditional merge control strategies cannot yield the expected effectiveness under heavy traffic conditions at freeway work zones because inevitable traffic conflicts resulting from complex merging and lane-changing maneuvers could increase the potential of traffic collisions, induce stop-and-go movements, and degrade the operational efficiency. This paper presents a dynamic control model to optimize the signal operations of a new merge system, the lane-based signal merge (LBSM), which uses lane-based signals or variable signs to give drivers in different lanes the right of way to proceed through the open lane(s) in a work zone area. The control objective is to maximize the work zone throughput. A genetic algorithm is employed to solve the model. Results reveal that the proposed method yields promising work zone operational performance under heavy traffic conditions.