In this paper, we investigate the effect of path establishment method priorities over routing performance in mixed line rate (MLR) wavelength division multiplexed (WDM) optical networks. The survivable routing with rate and wavelength assignment (SRRWA) problem is presented and an efficient shared backup path protection solution is proposed. We prepared detailed simulation scenarios with all possible prioritizations and observed their performances. The simulation results show that assigning higher priority to single hop methods as compared with multi-hop methods yields better performance. In both methods, it has been observed that assigning higher priority to grooming reduces the communication cost and the traffic blocking ratio while enhancing the resource utilization.