Neighborhood Area Networks (NANs) are an important part of the smart grid, which is the last one mile communication in a Smart Grid Communication Network (SGCN), and a routing algorithm is one of the key technologies to improve the performance of NANs. Designing routing metrics is critical for routing algorithm of NANs. The goal of the metric is to choose a high-throughput path between a source and a destination. In this paper, we focus on addressing this question. A new routing metric called Hybrid Metric (HM) is proposed to provide more reliable communication of NANs. Considering the resources consumed by a packet to a link, interference factors, and channel switching delay, HM effectively improved and made up for the present shortcomings of exiting routing metrics, such as ALM, ETX, ETT and HC. For simulations, we used an ns-3 simulator and Hybrid Wireless Mesh Protocol (HWMP). We evaluated the performance of the HWMP with HM in four parameters of (i) Packet Delivery Fragment, (ii) Packet Loss Ratio, (iii) throughput, and (iv) end-to-end delay. The results proved that HM improved Packet Delivery Fragment, Packet Loss Ratio, and throughput, but not the end-to-end delay.