PNS/BAFS PABES 289:2019 Philippine National Standard Agricultural Infrastructures – Farm-to-Market Roads – Concrete Roads PDF

PHILIPPINE NATIONAL PNS/BAFS PABES 289:2019 STANDARD ICS 65.040.01 Agricultural Infrastructures – Farm-to-Market Roads – Concrete Roads BUREAU OF AGRICULTURE AND FISHERIES STAND...

PHILIPPINE NATIONAL PNS/BAFS PABES 289:2019 STANDARD ICS 65.040.01 Agricultural Infrastructures – Farm-to-Market Roads – Concrete Roads BUREAU OF AGRICULTURE AND FISHERIES STANDARDS BPI Compound Visayas Avenue, Diliman, Quezon City 1101 Philippines Trunkline: (632) 928-8741 to 64 loc. 3301-3319 E-mail: [email protected] Website: www.bafs.da.gov.ph Contents Page Foreword................................................................................................................... iv 1 Scope.................................................................................................................. 1 2 Normative references.......................................................................................... 1 3 Terms and definitions.......................................................................................... 4 4 Typical Location of Farm-to-Market Roads........................................................ 11 5 General Components of Farm-to-Market Roads................................................ 11 6 Design Considerations....................................................................................... 12 6.1 General..................................................................................................... 12 6.2 Geometric Design..................................................................................... 13 6.3 Pavement Design..................................................................................... 21 6.4 Drainage Design....................................................................................... 24 6.5 Slope Protection Design........................................................................... 28 6.6 Miscellaneous Structures Design............................................................. 30 7 Materials and Construction Requirement........................................................... 33 7.1 Clearing and Grubbing............................................................................. 33 7.2 Excavation................................................................................................ 35 7.3 Structure Excavation................................................................................ 39 7.4 Embankment............................................................................................ 43 7.5 Subgrade Preparation.............................................................................. 48 7.6 Overhaul................................................................................................... 49 7.7 Aggregate Subbase Course..................................................................... 52 7.8 Aggregate Base Course........................................................................... 54 7.9 Lime Stabilized Road Mix Base Course................................................... 59 7.10 Portland Cement Stabilized Road Mix Base Course................................ 60 7.11 Asphalt Stabilized Road Mix Base Course............................................... 61 7.12 Portland Cement Concrete Pavement...................................................... 63 7.13 Slope Protection....................................................................................... 85 7.14 Drainage................................................................................................... 94 7.15 Miscellaneous Structures......................................................................... 98 8 Operation and Maintenance of Farm-to-Market Roads.................................... 104 ii Annex A (informative) Typical Plan and Profile of FMR.......................................... 105 Annex B (informative) Classification of Roads...................................................... 108 Annex C (normative) Minimum Stopping and Passing Sight Distance.................. 110 Annex D (normative) Recommended Permissible Velocities for Unlined Channels..................................................................................................... 111 Annex E (informative) Typical Road Safety Signs................................................. 112 Bibliography........................................................................................................... 113 iii  PHILIPPINE NATIONAL STANDARD PNS/BAFS PABES 289:2019 Foreword The Philippine National Standard (PNS) for Agricultural Infrastructures – Farm-to- Market Roads – Concrete Roads (PNS/BAFS PABES 2892019) has been prepared by the Bureau of Agriculture and Fisheries Standards (BAFS), in collaboration with the Technical Working Group (TWG) for Farm-to-Market Roads per approved Department of Agriculture Special Order (SO) No. 954 Series of 2016. This Standard replaces the provisions for concrete roads specified by PAES 421:2009 Agricultural Structures – Farm-to-Market Roads. This edition includes the following significant changes compared to the previous edition:  Focus on the provisions for concrete roads only  Modification in “Scope”  Modification in the definition of “Farm-to-Market Road” and other terms in “Terms and Definitions”  Revision of figure and provisions under “Typical location of Farm-to-Market Roads”  Addition of clause on “General Components of Farm-to-Market Roads”  Addition of terms and definitions related to bio-engineering slope protection and other terms in “Terms and Definitions”  Modification in Clause on “Design Considerations”, including considerations for geometric, pavement, drainage, slope protection, and miscellaneous structures design  Revision of minimum pavement thickness to 200mm  Revision of minimum pavement width for two-lane roads to 5m  Consolidation of applicable provisions under clause on “Materials and Construction Requirements”  Addition of materials and construction requirements for structure excavation, other types of aggregate base courses, slope protection, drainage, and miscellaneous structures  Deletion of clauses on “Method of Measurement” and “Basis of Payment”  Addition of clause on “Operation and Maintenance of Farm-to-Market Roads”  Addition of Annex A “Sample Plan, Profile, and Cross Section Plan of FMR”  Addition of Annex B “Classification of Roads”  Addition of Annex C “Minimum Stopping and Passing Sight Distances”  Addition of Annex D “Recommended Permissible Velocities of Channels”  Addition of Annex E “Typical Road Safety Signs” Provisions of this standard are based on the DPWH Standard Specifications for Public Works and Highways, Volume II – Highways, Bridges and Airports, 2013 Edition and other sources. This Standard has been technically prepared in accordance with International Organization for Standardization/International Electrotechnical Commission (ISO/IEC) Directives Part 2, 8th edition – Principles and rules for the structure and drafting of ISO and IEC documents. iv PHILIPPINE NATIONAL STANDARD PNS/BAFS PABES 289:2019 The word “shall” is used to indicate mandatory requirements to conform to the standard. The word “should” is used to indicate that among several possibilities one is recommended as particularly suitable without mentioning or excluding others. v  PHILIPPINE NATIONAL STANDARD PNS/BAFS PABES 289:2019 Agricultural Infrastructures – Farm-to-Market Roads – Concrete Roads 1 Scope This standard specifies the minimum requirements for the design, construction, and operation and maintenance of one-lane and two-lane concrete Farm-to-Market Roads for the purpose of, but not limited to, the preparation of program of works, detailed engineering design, procurement, monitoring, inspection, and evaluation. It covers the construction of new roads and upgrading of existing roads with Average Daily Traffic (ADT) equal or less than 400. 2 Normative References The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. Department of Public Works and Highways (DPWH) Design Guidelines, Criteria, and Standards Volume 4 (2015), Highway Design American Association of State Highway and Transportation Officials (AASHTO) (2011), A Policy on Geometric Design of Highways and Streets, 6th Ed. AASHTO (1993), Guide for Design of Pavement Structures DPWH Standard Specifications for Highways, Bridges, and Airports, Volume II (2013) PNS/BAFS/PAES 218:2017, Open Channels – Design of Main Canals, Laterals and Farm Ditches DPWH Highway Safety Design Standards Part 2 (2012), Road Signs and Pavement Marking Manual American Society for Testing and Materials (ATSM) A615/A615M, Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement AASHTO T 11, Standard Method of Test for Materials Finer than 75 μm (No. 200) Sieve in Mineral Aggregates by Washing AASHTO T 90, Standard Method of Test for Determining the Plastic Limit and Plasticity Index of Soils AASHTO T 89, Standard Method of Test for Determining Liquid Limits of Soil AASHTO T 99, Standard Method of Test for Moisture-Density Relations of Soils Using a 2.5-kg (5.5-lb) Rammer and a 305-mm Drop AASHTO T 191, Standard Method of Test for Density of Soil In-Place by the Sand- Cone Method  PNS/BAFS PABES 289:2019 ASTM D2167, Standard Test Method for Density and Unit Weight of Soil in Place by the Rubber Balloon Method ASTM D4718/D4718M, Standard Practice for Correction of Unit Weight and Water Content for Soils Containing Oversize Particles AASHTO T 96, Standard Method of Test for Resistance to Degradation of Small-size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine AASHTO T 193, Standard Method of Test for the California Bearing Ratio (CBR) AASHTO T 180, Standard Method of Test for Moisture- Density Relations of Soils Using a 4.54 kg (10 lb) Rammer and a 457 mm (18 in) Drop ASTM D 1632, Standard Practice for Making and Curing Soil-Cement Compression and Flexure Test Specimens in the Laboratory AASHTO T 134, Standard Method of Test for Moisture – Density Relations of Soil – Cement Mixtures ASTM D 1633, Standard Test Methods for Compressive Strength of Molded Soil- Cement Cylinders AASHTO M 85, Standard Specification for Portland Cement AASHTO M240M/M240 or ASTM C595/C595M, Standard Specification for Blended Hydraulic Cement AASHTO R 71, Standard Practice for Sampling and Amount of Testing of Hydraulic Cement AASHTO T 71, Standard Method of Test for Effect of Organic Impurities in Fine Aggregate on Strength of Mortar ASTM C 1602/C1602M, Standard Specification for Mixing Water Used in the Production of Hydraulic Cement Concrete AASHTO M31M/M31, Standard Specification for Deformed and Plain Carbon and Low-Alloy Steel Bars for Concrete Reinforcement AASHTO M42M/M42, Standard Specification for Rail-Steel Deformed and Plain Bars for Concrete Reinforcement ASTM D 6690, Standard Specification for Joint and Crack Sealants, Hot Applied, for Concrete and Asphalt Pavements AASHTO M 33 or ASTM D994/D994M, Standard Specification for Preformed Expansion Joint Filler for Concrete (Bituminous Type) 2  PNS/BAFS PABES 289:2019 AASHTO M 213, Standard Specification for Preformed Expansion Joint Fillers for Concrete Paving and Structural Construction (Nonextruding and Resilient Bituminous Types) ASTM D 2628, Standard Specification for Preformed Polychloroprene Elastomeric Joint Seals for Concrete Pavements AASHTO M194M/M194, Standard Specification for Chemical Admixtures for Concrete AASHTO M 144, Standard Specification for Calcium Chloride ACI Standard 211.1, Recommended Practice for Selecting Proportions for Normal and Heavyweight Concrete AASHTO T119M/T119, Standard Method of Test for Slump of Hydraulic Cement Concrete AASHTO T 97, Standard Method of Test for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading) AASHTO T 177, Standard Method of Test for Flexural Strength of Concrete (Using Simple Beam with Center-Point Loading) AASHTO T24M/T24, Standard Method of Test for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete AASHTO M 157, Standards Specification for Ready-Mixed Concrete ASTM C685/C685M, Standard Specification for Concrete Made by Volumetric Batching and Continuous Mixing AASHTO T 23, Standard Method of Test for Making and Curing Concrete Test Specimens in the Field AASHTO T 148, Standard Method of Test for Measuring Length of Drilled Concrete Cores ASTM C 171, Standard Specification for Sheet Materials for Curing Concrete AASHTO M 248, Standard Specification for Ready-Mixed White and Yellow Traffic Paints AASHTO M 249, Standard Specification for White and Yellow Reflective Thermoplastic Striping Material (Solid Form) AASHTO T 250, Standard Method of Test for Thermoplastic Traffic Line Material ASTM D 5167, Standard Practice for Melting of Hot-Applied Joint and Crack Sealant and Filler for Evaluation 3  PNS/BAFS PABES 289:2019 ASTM D 5329, Standard Test Method for Sealants and Filler, Hot-Applied, for Joints and Cracks in Asphalt Pavements and Portland Cement Concrete Pavements Philippine Rural Development Project (PRDP), Operation and Maintenance Manual for Rural Infrastructure Sub-projects DPWH Department Order No. 41 series of 2016, Amended Policy Guidelines on the Maintenance of National Roads and Bridges 3 Terms and Definitions For the purpose of this standard, the following terms shall apply. 3.1 access ramp slope located at the side of the road carriageway that provides entrance from lower ground levels 3.2 aggregates granular material of mineral composition such as sand, gravel, shell, crushed and uncrushed stone or lightweight materials 3.3 agriculture and fisheries production of crops, livestock, and aquatic flora and fauna 3.4 backfill suitable materials such as gravel, sand, and earth used to refill excavated materials during construction 3.5 backfilling the act of refilling suitable materials or replacing unsuitable materials removed during construction 3.6 base course layer of aggregate, soil-treated aggregate, treated soil, or soil aggregate of designed thickness that rests upon the Subbase or if no Subbase, upon the sub-grade, to support a surface course. 3.7 borrow suitable material used for embankments 4  PNS/BAFS PABES 289:2019 3.8 California Bearing Ratio (CBR) ratio between a test load and an arbitrarily defined standard load, expressed as a percentage 3.9 clearing removal and disposal of trees, vegetation or other unwanted materials from the ground surface 3.10 coco coir twine string made of coconut coir strands twisted together 3.11 coco coir peat natural and residual materials from coconut coir which serves as soil conditioner 3.12 coco-log tubular structure of coconut coir fiber blankets of different diameter filled with coco coir, and/or coco peat 3.13 coconet handspun coconut coir fiber twine woven into blankets of different density 3.14 coconut geonet any coconut coir fiber-based material such as coconets, coco-logs, coco peat, placed in sloping lands and embankments to hold the vulnerable soil and permit vegetative growth to control surface erosion and conserve the productivity of the soil 3.15 compaction application of pressure to soil materials to result in a dense mass free of excessive voids; minimizes settlement, decreases permeability and increases strength 3.16 concrete hardened mixture of fine and coarse aggregate, water, cement, and admixtures 3.17 Contractor entity having a Contract with a procurement agency and accredited by the Philippine Constructors Accreditation Board (PCAB) 3.18 course structural component of specified thickness; it may consist of one layer or more 5  PNS/BAFS PABES 289:2019 3.19 crossfall cross slope transverse slope that helps the carriageway to drain properly 3.20 culvert drainage structure that may or may not, directly support and that extends across and beneath a highway street, driveway, alley, arterial, or other public way 3.21 drainage removal of water from the road area by the use of culverts, ditches, channels and other several structures 3.22 earthwork operations connected with excavating and placing embankments with soil, earth or rock 3.23 embankment construction, usually of earth or stone, to raise the ground or formation level above the natural surface 3.24 Engineer a person authorized by law and registered and licensed by the Professional Regulation Commission (PRC) to design and supervise the construction of Farm-to-Market Roads; refers to the engineer of the implementing agency 3.25 Equivalent Single Axle Load (ESAL) load from the conversion of an expected axle load into an equivalent number of 18-kip single axle load 3.26 erosion control protection of soil from disclosing by water, wind, or other agent 3.27 excavation act of cutting, digging, or scooping to remove material 3.28 farm place devoted for agricultural and fisheries production 6  PNS/BAFS PABES 289:2019 3.29 Farm-to-Market Roads (FMR) road within the agriculture and fisheries production areas, coastal landing points, and postharvest or processing facilities that links to local roads, national highways, and markets. 3.30 Field Density Test (FDT) determination of the degree of compaction of the soil 3.31 fill suitable embankment materials placed above natural ground line 3.32 geotextile fabrics used in subsurface drainage, hydraulic filter, erosion control, sediment control, pavement structures and used as waterproofing and stress relieving membrane, and as a permeable separator to prevent mixing of dissimilar materials such as foundations and select fill materials 3.33 grade slope of a roadway, channel, or natural ground 3.34 gradation property of a soil which describes the distribution of size groups 3.35 gradient rate of increase or decrease in the level of the land, the slope expressed in percentage 3.36 grading preparation of the sub-grade, in line and elevation, for application of pavement materials including base and surfacing materials 3.37 grubbing removal and disposal of trees, and other unwanted materials below the ground surface 3.38 intersection general area where two or more roads, within which are included the roadway and roadside facilities for traffic movements in that area 3.39 lane roadway roadway with single, two, or more clearly marked lanes for vehicular traffic 7  PNS/BAFS PABES 289:2019 3.40 local roads road that predominantly carries through traffic from one area to another, forming principal avenues of travel for traffic movements which include provincial, municipal, city, and barangay roads 3.41 market a place, building, or structure where buyers and sellers meet for the sale or purchase of agriculture and fisheries products 3.42 masonry form of stone, brick, concrete block, concrete, or other similar building materials that have been bonded together with mortar to form a structure 3.43 one-lane concrete road concrete roadway, with clearly marked single or one lane for vehicular traffic 3.44 Plans the contract drawings which show the locations, character, and dimension of the prescribed work, including layouts, profiles, cross sections, and other details 3.45 Right of Way (ROW) a part or the entirety of the property, site, or location with defined physical boundaries used or required by a government project 3.46 riprap quarried stone especially selected, graded and placed to prevent erosion and thereby preserve the shape of a surface, slope, or underlying structure 3.47 road carriageway portion of a road intended for the movement of vehicles, exclusive of shoulders (see Figure 1) 3.48 road carriageway width lateral design width for one lane or two lanes strip of roadway 3.49 road shoulder portion of the roadway contiguous with the travelled way for accommodation of stopped vehicles, for emergency use, and for lateral support of base and surface courses (see Figure 1) 8  PNS/BAFS PABES 289:2019 3.50 road upgrading civil works covering removal, replacement, widening of pavement, and/or increase of thickness of pavement to ensure road safety and easier road safety 3.51 roadbed graded portion of a road between top and side slopes, prepared as a foundation for the pavement structure and shoulders 3.52 roadway space, location, or site intended to employ traffic consideration, preferably for the transport of agricultural and fisheries products (see Figure 1) Road carriageway Road shoulder Roadway Figure 1 – Two-lane concrete roadway 3.53 salvage materials saving of different existing materials from the projects which are removed and intended to be used in other construction 3.54 sidewalk portion of the roadway primarily constructed for the use of pedestrians 3.55 sight distance distance at which a driver of a vehicle can see an object of specified height on the road ahead, assuming adequate sight and visual acuity and clear atmospheric conditions 3.56 shoulder rollover difference in crossfall between the pavement and its adjacent shoulder 3.57 specifications written technical description of materials, equipment, construction systems, standards, and workmanship that, in conjunction with the drawings, detail the requirements for acceptable completion of the work 9  PNS/BAFS PABES 289:2019 3.58 structures bridges, culverts, wall, buildings, foundations, water tanks, transmission towers, cribbing, caissons or coffer dams, other similar features which may be encountered in the work and are classified as structures 3.59 subbase layer layer of the specified or selected materials, treated or untreated, of designated thickness in a pavement structure immediately above the sub-grade and below the pavement 3.60 subgrade top surface of the roadbed upon which the pavement structure is placed 3.61 suitable materials material which is acceptable in accordance with the contract and which can be compacted 3.62 superelevation cross slope of the pavement at a horizontal curve, provided to partially counterbalance the centrifugal force on a vehicle going around that curve. 3.63 traffic vehicular and non-vehicular movement along a route such as pedestrians, vehicles, animals, etc. 3.64 two-lane concrete pavement road concrete pavement roadway, on which two lanes are marked for vehicular traffic 3.65 turnout a widened, unobstructed shoulder area that may be used for emergency purposes or allow slow-moving vehicles to pull out of the carriageway to give passing opportunity to following or incoming vehicles 3.66 unsuitable materials materials not appropriate and safe for backfill and borrow which include garbage etc. 3.67 weep hole an opening provided during construction in retaining walls, aprons, canal linings, foundation, etc., to permit drainage of water collecting behind and beneath such structures to reduce hydrostatic head. 10  PNS/BAFS PABES 289:2019 4 Typical Location of Farm-to-Market Roads 4.1 FMRs shall be located within key production areas, marginal lands or new lands within the Strategic Agricultural and Fisheries Development Zones (SAFDZs), comprehensive land use (CLUP), and other convergence initiative areas of concerned agencies to provide easy and optimum access for the mobility of agriculture and fishery products. (See Figure 2) Figure 2 – Typical location of FMR 4.2 Roads shall prioritize the conveyance of goods and services within or to and from the production areas, primary assembly areas, major markets/trading posts, fishing ports, fishpond/fish cage areas, agricultural and maricultural zones, postharvest facilities and processing zones/industries. 5 General Components of Farm-to-Market Roads The typical plan and profile of FMR, along with the required contents of a plan and profile, are shown in Annex A. The general components of a one-lane and two-lane roadway are shown in Figure 3 and 4, respectively. 11  PNS/BAFS PABES 289:2019 Figure 3 – General components of a one-lane FMR Figure 4 – General components of a two-lane FMR 6 Design Considerations 6.1 General 6.1.1 Farm-to-Market Roads shall be designed to ensure efficient movement of goods and services with utmost consideration for the convenience and safety of the motorists and pedestrians. Aesthetics and environmental impacts shall be taken to account in the most economical manner and consistent with the prescribed design standards. 6.1.2 The road shall be constructed on elevated portions and, if possible, should not pass through swampy, logged-over and flooded areas. The embankment height shall be at least 0.6 m higher than the flood level of the area. 12  PNS/BAFS PABES 289:2019 6.1.3 Roads shall provide adequate and efficient route within the road influence area. 6.1.4 Roads shall be designed and arranged with appropriate regard for topography, creeks, wooded areas and other natural features which would enhance attractive development. 6.1.5 Roads shall be equipped with traffic signs, side rails, road markings, and other safety structures, as appropriate. 6.1.6 The design must be suitable for the anticipated traffic volume, design speed, and character of the vehicles that will use the facility. 6.1.7 Traffic analysis, field survey, and geotechnical investigation in accordance with the DPWH Design Guidelines, Criteria, and Standards (DGCS) (2015) shall be conducted prior to the preparation of Plans. 6.1.8 Road connections should follow the road hierarchy to avoid road usage beyond its design ADT. 6.2 Geometric Design 6.2.1 Design Speed Design speed is a factor used as reference to various design features of the alignment such as radius, grade, superelevation, and sight distances. Geometric Design features should be consistent with the projected usage and environmental conditions of the terrain. The prescribed minimum design speed based on the terrain type and projected ADT for the road is shown in Table 1. Table 1 – Minimum design speed Type of Design Speed (kph) for Specific Design Volume Terrain Under 50 50-250 250-400 Level 50 50 60 Rolling 30 50 50 Mountainous 30 30 30 [SOURCE: Table 5-1, A Policy on Geometric Design of Highways and Streets, 2011, by the American Association of State Highway and Transportation Officials, Washington, D.C., U.S.A. Used with permission.] 6.2.2 Horizontal Curves Alignment should be as directional as possible and consistent with the topography. Generally, flatter curves should be used whenever applicable and curves of maximum degree should be avoided except for critical conditions. 13  PNS/BAFS PABES 289:2019 The recommended minimum radius shall be 30 m. Where curves are superelevated, lower values may apply, but should not be less than 25 m for 30 kph design speed. 6.2.3 Gradient The suggested maximum grades as a function of type of terrain and design speed are shown in Table 2. Table 2 – Maximum grades Maximum Grade (%) for a Specific Design Speed (kph) Type of Terrain 30 40 50 60 Level 8 7 7 7 Rolling 11 11 10 10 Mountainous 16 15 14 13 [SOURCE: Table 5-2, A Policy on Geometric Design of Highways and Streets, 2011, by the American Association of State Highway and Transportation Officials, Washington, D.C., U.S.A. Used with permission.] Minimum grade for paved surfaces shall be 0.30% to facilitate surface drainage on curbed and cut sections. The maximum design grade should be used only infrequently; in most cases, grades should be less than the maximum design grade. 6.2.4 Critical Lengths of Grade for Design Based from 20-tonne truck which will affect a reduction in speed of 25 kph below the average running speed, the prescribed critical lengths of upgrades are shown in Table 3. For other design gross vehicle capacity, the critical lengths of upgrades shall be computed according to AASHTO A Policy on Geometric Design of Highways and Streets (2011). Table 3 – Critical lengths of upgrades Critical Length of Upgrade, % Upgrade, m 500 3 340 4 240 5 200 6 170 7 150 8 [SOURCE: Table 3-33, DPWH Design Guidelines, Criteria, and Standards Volume 4 (2015)] The above critical lengths of upgrade should not be used as a control but should be referred to as a guide. Climbing lane or turnouts on the uphill side should be provided for long upgrades. 14  PNS/BAFS PABES 289:2019 6.2.5 Vertical Curves Vertical curves shall be provided on grade breaks with algebraic difference in grade greater than 0.5%. Minimum length of curve shall be 40 m. Design controls based on sight distances for sag and crest are indicated in Table 4. Table 4 – Design controls for vertical curves Stopping Sight Distance Passing Sight Distance Initial Rate of Vertical Rate of Vertical Speed Sight Sight Curvature, K* (m/%) Curvature, K* (kph) Distance Distance Crest Sag (m/%) 30 35 2 6 120 17 40 50 4 9 140 23 50 65 7 13 160 30 60 85 11 18 180 38 70 105 17 23 210 51 80 130 26 30 245 69 *Rate of Vertical Curvature, K, is the length of curve per percent algebraic difference in intersecting grades (i.e., K=L/A). [SOURCE: Table 5-3 and 5-4, A Policy on Geometric Design of Highways and Streets, 2011, by the American Association of State Highway and Transportation Officials, Washington, D.C., U.S.A. Used with permission.] 6.2.6 Superelevation Superelevation (e) on horizontal curves shall be provided for FMR whenever practical. Minimum tangent of 30 m shall be provided for the runoff section. Maximum superelevation and maximum shoulder rollover of 8% shall be used. The minimum radii within a range of superelevation rates are tabulated in Table 5. Table 5 – Minimum radii and superelevation Vd=30 kph Vd=40 kph Vd=50 kph Vd=60 kph e(%) R(m) R(m) R(m) R(m) -1.5 27 59 113 183 0 25 55 104 167 1.5 24 51 96 153 2.0 24 50 94 149 2.2 23 50 93 148 2.4 23 50 92 146 2.6 23 49 91 145 2.8 23 49 90 143 3.0 23 48 89 142 3.2 23 48 89 140 15  PNS/BAFS PABES 289:2019 Vd=30 kph Vd=40 kph Vd=50 kph Vd=60 kph e(%) R(m) R(m) R(m) R(m) 3.4 23 48 88 139 3.6 22 47 87 138 3.8 22 47 86 136 4.0 22 47 86 135 4.2 22 46 85 134 4.4 22 46 84 132 4.6 22 46 83 131 4.8 22 45 83 130 5.0 21 45 82 129 5.2 21 45 81 128 5.4 21 44 81 127 5.6 21 44 80 125 5.8 21 44 79 124 6.0 21 43 79 123 6.2 21 43 78 122 6.4 21 43 78 121 6.6 20 43 77 120 6.8 20 42 76 119 7.0 20 42 76 118 7.2 20 42 75 117 7.4 20 41 75 116 7.6 20 41 74 115 7.8 20 41 73 114 8.0 20 41 73 113 [SOURCE: Table 3-13a, A Policy on Geometric Design of Highways and Streets, 2011, by the American Association of State Highway and Transportation Officials, Washington, D.C., U.S.A. Used with permission.] Minimum value for radius as discussed in Clause 6.2.2 shall govern. An illustration of superelevation is shown in Figure 5. 16  PNS/BAFS PABES 289:2019 Figure 5 – Superelevation for left and right turning curves [SOURCE: Massachusetts Department of Transportation (2006)] 6.2.7 Widening on Curves Due to the fact that on curves the rear wheels of motor vehicles do not ordinarily travel in the same radius as the front wheels, the roadbed should be widened especially along sharp curves. A curve is considered a sharp curve when it is below the recommended minimum radius for a given design speed. The minimum widening recommended on curves should be 0.60 m and should depend on the degree of curvature, design speed, and design vehicle. The material of the widened section shall be made of the same material as the carriageway. 6.2.8 One-lane roadway A one-lane roadway shall be constructed in places where only light vehicles pass through and with ADT less than 50. There shall be provisions of turnout in strategic locations for maneuver of two vehicles traveling in opposite directions and in critical sections especially on steep grades along mountainous areas. Turnout shall be about 1 m wide and 60 m long as shown in Figure 6. The minimum distance of consecutive turnouts shall be 1000 m. 17  PNS/BAFS PABES 289:2019 Figure 6 – One-lane roadway with turnout section 6.2.9 Site of road expansion for one-lane roadway The road shall be constructed either left or right from the center of the existing ROW in order to accommodate expansion in the future. The design of the roadside ditch within the ROW should be earth ditch, since it will be damaged during expansion. However, steep slope ditch should be constructed of other materials to prevent erosion. An illustration of a typical one-lane concrete road for expansion is shown in Figure 7. Figure 7 – Typical site for one-lane conrete road for expansion 18  PNS/BAFS PABES 289:2019 6.2.10 Road carriageway The road carriageway shall provide space for the safety and convenient movement of the vehicles. The minimum road carriageway width requirement for one-lane and two-lane roadway is summarized in Table 6. Table 6 – Minimum road carriageway and road shoulder width requirement Road lane ADT Minimum pavement Minimum road width (m) shoulder width (m) One lane