The total transmission capacity required by a transport network to satisfy demand and protect it from failures contributes significantly to its cost. Unlike SCP (Spare Capacity Placement) scheme, JOCP (Jointly Optimized Capacity Placement) scheme could reach more optimal results since it tries to jointly optimize both working and spare capacity. However, the later is more complex and time-consuming according to previous research based on IP solution. This paper presents a heuristic algorithm MSC-JOCP, which is based on shared-path protection, to address this problem. The key idea of the algorithm is to dynamically modulate the metrics of the network?s spans, so as to choose primary and backup routes given attention to load balancing as well as maximally share the spare capacity. Simulation results show that the developed scheme effectively reduces the required total capacity and enhances the network resource utilization.