2.3 Subsurface drainage systems (culverts) - - - - - - - - - - - - - - - .. 8
2.4 Alignment of Drainage System - - - - - - - - - - - ..
2.5 Description and Function of Road Drainage System - - - - - - - - - - - - . 9
2.5.1 Description of Road Drainage Systems - - - - - - - - - - - - 9
2.5.2 Functions of Road Drainage Systems - - - - - - - - - - - - .. 10
2.6 Failures of Road Drainage System - - - - - - - - - - - - - - - - ..Effects
2.7 Effects of Poor Drainage on Roads - - - - - - - - - - - - - - - - . poor
2.8 By poor drainage effects of water on road - - - - - - - - - - - - - - 11
2.9 Culverts - - - - - - - - - - - - - - - - - - - - - - - - . 11
2.10 Components of a road and pavement drainage system - - - - - - - - - - 13
2.10.1 Ditches - - - - - - - - - - - - - - - - - - - - .Erosion
2.10.2 Erosion Control in Ditches - - - - - - - - - - - - - - - . 14
2.11 Necessities to Construct Drainage System - - - - - - - - - - - - - 14
2.12 The Criteria for Roadside Channels - - - - - - - - - - - - - - - 15
2.13 Design Flood for Road Drainage System - - - - - - - - - - - - - .. 15
2.14 Flow Velocity in Road Drainage System - - - - - - - - - - - - - - 15
CHAPTER THREE: - - - - - - - - - - - - - - - - - - .16 METHODOLOGY - - - - - - - - - - - - - - - - - - - ..16 3.1 Research Methodologies - - - - - - - - - - - - - - - - - - - .16
3.2 Selection of the Study Area - - - - - - - - - - - - - - - - - - ..period
3.3 Study period - - - - - - - - - - - - - - - - - - - - - ..18
3.4 Research design - - - - - - - - - - - - - - - - - - - - - .. 18
3.5 Study population - - - - - - - - - - - - - - - - - - - - - ..