4.0 Highway Design Data - Drainage Recommendations & Design Controls

Question 1

It refers to the system of providing ways to remove water from a pavement.

Answer 1

Drainage

Question 2

refers to collection, conveyance, removal and disposal of water running the surface, the water coming as precipitation in the form of rainwater.

Answer 2

Good Drainage System

Question 3

therefore, should be given the same careful consideration as required for pavement and other road facilities.

Answer 3

Drainage facilities

Question 4

It means the drainage of surface water produced by rainfall on a roadway and from areas other than the right-of-way.

Answer 4

Surface Drainage

Question 5

Cross slope requirements vary based on road surface conditions:

Answer 5

1.5% or 2.5% for cement concrete or asphalt

3% to 4% Gravel Roads

Question 6

The recommended minimum longitudinal slope is

Answer 6

0.50%

Question 7

It affects stormwater flow time and drainage inlet efficiency.

Answer 7

Longitudinal Slope

Question 8

What to do if slopes greater than 4%

Answer 8

both sides of the side ditch/canal and shoulder should be paved to prevent increased water velocity scouring.

Question 9

It is placed only if the selected road uses a road style with a curb. These are placed at low points along the road curb, spaced from high points based on the maximum inlet spacing defined on the Pavement Drainage Design Standard.

Answer 9

Inlet

Question 10

The maximum spacing for curb inlet and manhole is

Answer 10

20m

Question 11

Road drainage should be assigned for a ____ Flood Design Capacity, with a check capacity of a ____ flood.

Answer 11

15 year Flood Design Capacity, check capacity of a 20 year Flood.

Question 12

In order to encourage self-cleaning, and minimize sediment build up, pipes should be designed to ensure a minimum flow velocity of ____ at pipe full.

The maximum velocity to be adopted for piped drainage system is ____.

Answer 12

minimum velocity is 0.8m/s
maximum velocity is 5m/s

Question 13

What is the minimum size of pipe to be adopted in order to allow the passage of debris and minimize the risk of blockage.

Answer 13

910mm

Question 14

What is placed at inlet locations at an offset based on the horizontal and longitudinal placement offset defined on the Pavement Drainage Design Standard.

Answer 14

Manhole

Question 15

Level of Service

A
B
C
D
E
F

Answer 15

A - Free Flow
B- Reasonably Flow
C- Stable Flow
D- Appproaching Unstable Flow
E- Unstable Flow
F- Forced or Breakdown Flow

Question 16

It is intended to reduce the groundwater level and to intercept and drain water infiltrating from the adjoining areas and road surface or rising from the subgrade.

Answer 16

Subsurface Drainage

Question 17

Whenever practicable the water table should be prevented from rising to within ____ below the bottom of the sub-base.

Answer 17

0.60m

Question 18

It is constructed to protect slopes from erosion or stability decline, which is caused by surface water on the cuts, fills, and natural slopes, or by groundwater oozing to the slope surface.

Answer 18

Slope drainage

Question 19

It is for the purpose of removing stored water from the backfill of structures and surface runoff on bridges caused by rainfall.

Answer 19

Drainage of Structure

Question 20

It is the speed determined for design and correlation of the physical features of a highway that influence vehicle operation. It is the maximum safe speed that can be maintained over a specified section of the highway when conditions are so favorable that the design features of the highway govern.

Answer 20

Design Speed

Question 21

It is the operating characteristics of motor vehicles should be considered in analyzing a facility. The major considerations are vehicle types and dimensions, turning radii and off- tracking, resistance to motion, power requirements, acceleration performance, and deceleration performance.

Answer 21

Design Traffic