Chapter 3: Local Road Planning 61 defined and structured in terms of the following hierarchy: a. External Linkages. These are local roads that facilitates external linkages to the LGU, with the following attributes: i. Access routes to the LGU and key transport infrastructure and facilities; ii. Most important linkages and main functions compared to other similar facilities in other LGUs; iii. Linkages and/or facilities that should be given the highest priority for improvement and likely effects of such improvement; and iv. Describe proposed new external linkages and rationale for these proposed linkages. v. Internal Circulation. These are local roads that provides internal circulation within the LGU having the following attributes: vi. Main internal circulation routes, infrastructure, and facilities of the different modes of road transport; vii. Importance of routes and their significance, main functions, key destinations; viii. Access to urban centers and non-urban production areas; ix. Characteristics of the routes and transport facilities and some indicators of quality, capacity, extent of usage, and road density such as: x. Length of local government roads by surface type; and xi. Percentage of paved roads. xii. Considering settlement trends, physical resources and protection areas, production requirements and identified priority industries: xiii. Priority and rationale for improvement among internal routes; and xiv. Proposed new routes and transport facilities and rationale. 3.3 Core Road Network Approach The core road network of an LGU is the optimum number of roads that contribute most to the transport network in support of the development