For Traffic engineering (TE) in QoS control, load balancing routing scheme of large IP backbone networks becomes a critical issue. Provisioning network resource in load balance is very difficult to ISPs because the traffic volume usually fluctuates widely over time and short duration flow has its bursty arrival process. In the paper, we propose the optimized alternate path routing schemes for short duration flow when congestion occurs. Our simulation result shows the proposed algorithm has less packet loss probability and less resource waste under heavy traffic load when we restrict the additional hop count by one or two.