Abstract—This work provides a practical method for the development of rural road networks in rural areas of developing countries. The proposed methodology enables to determine obligatory points in the rural road network maximizing the number of settlements that have access to basic services within a given maximum distance. The proposed methodology is simple and practical, hence, highly applicable to real-world scenarios, as demonstrated in the definition of the road network for the rural areas of Nepal. Keywords—Minimum spanning tree, nodal points, rural road network. I. INTRODUCTION EPAL has a total population of 26.5 million with 83% living in rural areas [1]. 87% of the total area of Nepal lies in hills (52%) and mountains (25%). Construction of rural roads is one of the major infrastructure development projects in Nepal in order to improve accessibility in rural areas. Accessibility in the rural areas is the easiness of getting facilities and services that the rural residents need for everyday life at minimum time, effort and cost [2]. Planning the road network in rural areas is therefore crucial, not only in terms of network efficiency (concerning accessibility), but also regarding construction and operation costs, as limited funding is available. There are different planning methodologies for the definition of rural road networks. The most relevant methodologies are United Nations Centre for Human Settlements [3], International Labor Organization (ILO) [4], Department of Local Infrastructure and Agricultural Roads (DoLIDAR) [5], and Computer aided method [6] in the rural context of Nepal. Also, it can be found different rural road planning methods proposed by different authors. The relevant models in the context or rural areas are GIS based model [7], facility based model [8], settlement based interaction model [9], and road planning in rural areas [10], [11]. However, most of these methods are associated with prioritization procedures requiring huge volume of data collection from rural areas which is time consuming and costly. This has made the J. K. Shrestha is with the Civil Engineering Department, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro, Tel: +351 234370049 (e-mail: jagatshrestha@ioe.edu.np). A. Benta and N. Lopes are with the Civil Engineering Department, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (e- mail: benta@ua.pt, nuno.lopes@ua.pt). R. B. Lopes is with the Economics, Management and Industrial Engineering Department, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (e-mail: rui.borges@ua.pt). planning of a road network in rural areas a complex job hampering the design of an effective network in the planning phase paying more attention to the prioritization indicators and process. In many models, the prioritization process is very complex taking too many indicators for ranking road links, some of them possibly irrelevant. Many indicators consider social and economic aspects, from which only few of them may be significant in the context of rural areas. Typically, rural roads are constructed in order to connect the rural settlements, thus improving accessibility. Therefore, road access to the settlements may be the most significant indicator. In case of Nepal, most of the rural road projects are being implemented at a district level (Nepal has 75 districts), based on the District Transport Master Plan (DTMP). DoLIDAR has published a manual providing a set of guidelines for the preparation of the DTMP [5]. Mainly, four major steps are proposed: inventory of rural road networks; collection of demands from the lowest level of political units (Village Development Committee – VDC); preparation of perspective plan (long list of road links); and preparation of 5 year rural road master plan (after prioritization of rural road links). The 5 year rural road master plan is referred as the DTMP. The DTMP preparation process focuses on discussions, debates and approval by local stakeholders, being the most important basis for development of the district level road network. Usually, various implementing partners are involved in road construction in the district as the rural development program. The DoLIDAR manual constitutes the guiding document for the planning of rural roads in Nepal. The most recent version of the DTMP manual [5] incorporates the Centrality Index concept as used by [6] to define a hierarchy for market centers (the manual focuses mostly in connecting market centers). However, the analysis for rural road network considering accessibility to the settlements is still lacking. It is not clear that the developed networks are effective concerning the connection/covering of settlements in the rural areas. Also, all the settlements in rural areas cannot be connected by roads due to technical and financial constraints. However, the settlements can be covered within a reasonable distance introducing nodal points in the planning regions. If the nodal points are established properly, all the settlements can be covered and access to roads may be better. Otherwise, the settlements may be beyond the coverage, which is not desirable. Hence, the main problem in the planning process is identification of nodal (obligatory) points to connect/cover the rural settlements. If the nodal points can be determined properly the network can be J. K. Shrestha, A. Benta, R. B. Lopes, and N. Lopes A Methodology for Definition of Road Networks in Rural Areas of Nepal N World Academy of Science, Engineering and Technology International Journal of Civil and Environmental Engineering Vol:7, No:6, 2013 422 International Scholarly and Scientific Research & Innovation 7(6) 2013 scholar.waset.org/1307-6892/13942 International Science Index, Civil and Environmental Engineering Vol:7, No:6, 2013 waset.org/Publication/13942