This study was conducted to examine the Rural Transport Accessibility Index and improve the connectivity of the rural road network for agricultural development in the Sunamganj district, Bangladesh, and facilitate the distribution of agricultural products as well as its accessibility to people. The demographic, socioeconomic, and agricultural data of eleven Upazila’s were obtained from the Bangladesh Bureau of Statistics (BBS) in order to fulfill the goals of this study. The administrative area boundary and transport network data were collected from the Local Government Engineering Department (LGED) and Roads and Highways Department (RHD), respectively. Rural Transport Accessibility was estimated using ArcGIS-Arc Map. Analyzes were performed using the Microsoft Excel Analysis Tool pack. To determine the priority ranking, Data Envelopment Analysis (DEA) and correlation analysis were used. The outcome of this method helped in ranking the Dharamapasha, Derai, Jagannathpur, Sullah, Tahirpur, Dakshin Sunamganj, Jamalganj, Chhatak, Dowarabazar, Bishwamvarpur, and Sunamganj Sadar Upazilas respectively inspect accessibility level. Improving rural road network considering agricultural productivity per kilometer and prioritizing the road ranking was prepared from the maximum habitations within the desired distance. These 121 links (Upazila Distance Matrix) were calculated. From Bishwamvarpur to Sunamganj Sadar, the maximum utility value was 12281.0. This link will be upgraded as the priority, and Jagannathpur to Sullah links will be upgraded as the least priority because of its minimum value of 149.9.