In this paper, an enhanced feathery receiver initiated transmission (eF-RIT) protocol is proposed for wireless smart utility network (Wi-SUN) systems with high traffic bi-directional communications such as emergency gas automatic meter infrastructure (AMI) cases. Firstly, we evaluate the conventional F-RIT protocol by simulation and experiment. The measurement results show that the IEEE 802.15.4e compliant conventional F-RIT protocol can achieve over 90% transmission success rates under the practical AMI specified conditions. However, the transmission success rates decline in high traffic environments. Detailed analyses indicate the degradation of the performance is caused by the timeout problem which occurs when the destination terminal is in the wait duration of the data transmission, and so does not transmit an RIT data request frame. To overcome this problem, we propose the eF-RIT protocol that suppresses the frequency of timeout occurrence. The proposed eF-RIT protocol is also evaluated by simulation and experiment. The evaluation results indicate that the proposed eF-RIT protocol reduces the incident of timeout by up to 31%, and achieves transmission success rates as high as 90% when the data generation rate is 1.0×10^-2s^-1.