Module 3

Question 1

It deals with the dimensioning of the elements of highway, such as vertical and horizontal curves, cross sections, truck climbing lanes, bicycle paths, and parking facilities.

Answer 1

Geometric Design

Question 2

The characteristics of these serve as the basis for determining the physical dimensions of these elements.

Answer 2

1. driver
2. pedestrian
3. vehicle
4. road

Question 3

When one considers the diversity of _____________ and ____________ and the interaction of these characteristics with the many elements constituting highway design, it is clear that proper design is a complex procedure that requires numerous compromises.

Answer 3

1. vehicle’s performance
2. physical dimensions

Question 4

It is a complex procedure that requires numerous compromises.

Answer 4

Proper design

Question 5

True or False. It is unnecessary that design guidelines evolve over time in response changes in vehicle performance and dimensions, and in response in evidence collected on the effectiveness of existing highway design practices, such as relationship between crash rates and various roadway design characteristics.

Answer 5

False

Question 6

It is important that design guidelines evolve over time in response to what?

Answer 6

1. changes in vehicle performance
2. changes in vehicle dimensions
3. evidence collected on the effectiveness of existing highway design practices

Question 7

They all rely on a basic understanding of vehicle performance.

Answer 7

determination of the length of :
1. freeway acceleration and deceleration lanes
2. maximum highway grades
3. stopping sight distances
3. passing sight distances
4. numerous accident-prevention devices

Question 8

What is the fundamental objective of geometric design?

Answer 8

to produce a smooth-flowing and safe highway facility, an objective that can be achieved by providing consistent design standard that satisfies the characteristics of the driver and the vehicles that use the road.

Question 9

It serves a critical function in developing guidelines and standards used in highway geometric design.

Answer 9

American Association of State Highway and Transportation Officials (AASHTO)

Question 10

Highway design is based on specified design standards and controls which depend on the following roadway system factors:

Answer 10

1. Functional classification
2. Design hourly traffic volume and vehicle mix
3. Design speed
4. Design vehicle
5. Cross section of the highway, such as lanes, shoulders, and medians
6. Presence of heave vehicles on steep grades
7. Topography of the area that the highway traverses
8. Level of service
9. Available funds
10. Safety
11. Social and environmental factors

Question 11

What are the principal factors used to determine the standards to which a particular highway will be designed?

Answer 11

1. Level of service to be provided
2. Expected traffic volume
3. Design speed
4. Design vehicle

Question 12

What are the principal elements of a highway cross section?

Answer 12

1. travel lanes
2. shoulders
3. medians

Question 13

These include median and roadside barriers, curbs, gutters, guard rails, sidewalks, and side slopes.

Answer 13

Marginal elements

Question 14

The cross section of a typical highway has latitude of variables to consider such as:

Answer 14

1. Volume of Traffic
2. Character of the Traffic
3. Speed of the Traffic
4. Characteristics of motor vehicles and of the driver

Question 15

True or False. Highway design usually adopted cross section that is uniform in thickness from end to ed of the improvement. This is acceptable on high volume traffic road facilities.

Answer 15

True

Question 16

For ____________ traffic facilities, modification of the features like the shoulders width in rough areas are usually employed to reduce costs.

Answer 16

low volume

Question 17

It is defined as that portion of the roadway between the edge of the traffic lane and the edge of the ditch, gutter, curb or side slope.

Answer 17

Road shoulder or verge

Question 18

AASHTO requires that its usable pavement width should be strong enough to support vehicles.

Answer 18

Road shoulder

Question 19

It is provided in all tangent sections of the roadway.

Answer 19

Cross slope

Question 20

It usually falls in both directions from the centerline of the two-lane highway except where super elevation of curves directs all water towards the inside.

Answer 20

Slope

Question 21

For high type pavement the crown or slope is often ____ to _____.

Answer 21

1% to 2%

Question 22

These are strongly recommended because rainwater flows away more rapidly reducing the water thickness on the road pavement.

Answer 22

Steeper slopes

Question 23

The __________ in one direction of multi-lane highways makes driving comfortable, but with heave rainfall, the water depth increases on the roadway.

Answer 23

cross slope

Question 24

These are provided on embankments and fills to provide stability for earthworks.

Answer 24

Side slopes

Question 25

They serve as a safety feature by providing a recovery area for out-of-control vehicles.

Answer 25

Side slopes

Question 26

_________ of normal height is safe on a slope of 1:2 ratios. Meaning, the first number represents the horizontal distance while the second number is the vertical distance.

Answer 26

Earth fill

Question 27

It is determined from the estimated traffic volume for the design year (AADT) and highway lane capacity at expected level of service.

Answer 27

number of lanes in a segment of the highway

Question 28

It is the section of a divided highway that separates the lanes in opposing directions.

Answer 28

Median

Question 29

It is the distance between the edges of the inside lanes, including the median shoulders.

Answer 29

width of median

Question 30

It is a defined area between traffic lanes for control of vehicle movement and for pedestrian refuge.

Answer 30

Island

Question 31

True or False. Within an highway, median is considered an island.

Answer 31

False (intersection not highway)

Question 32

It is defined as the longitudinal profile of the highway as a measure how the centerline of the highway rises and fall.

Answer 32

Grade line

Question 33

It appears on a profile taken along the road centerline.

Answer 33

Grade line

Question 34

It is a series of straight lines connected by parabolic vertical curves to which straight grades are tangent.

Answer 34

Grade line

Question 35

These are raised structures made of either Portland cement concrete or bituminous concrete (rolled asphalt curbs) that are used mainly on urban highways to delineate pavement edges and pedestrian walkways.

Answer 35

Curbs

Question 36

These are also used to control drainage, improve aesthetics, and reduce right of way.

Answer 36

Curbs

Question 37

These are usually located on the pavement side of a curb to provide the principal drainage facility for the highway.

Answer 37

Gutters or drainage ditches

Question 38

They are sloped to prevent any hazard to traffic.

Answer 38

Gutters or drainage ditches

Question 39

These are longitudinal barriers placed on the outside of sharp curves and at sections with high fills.

Answer 39

Guard rails

Question 40

Their main functions is to prevent vehicles from leaving the roadway.

Answer 40

Guard rails

Question 41

These are usually provided on roads in urban areas but are uncommon in rural areas.

Answer 41

Sidewalks

Question 42

The provision of ___________ in rural areas should be evaluated during the planning process to determine sections of the road where they are required.

Answer 42

sidewalks

Question 43

It is the total land area acquired for the construction of a highway.

Answer 43

Right of way

Question 44

True or False. In Right of Way, the width should be sufficient to accommodate all the elements of the highway cross section, any planned widening of the highway, and public-utility facilities that will be installed along the highway.

Answer 44

True

Question 45

True or False. Acquisition of land for the right of way is very cheap.

Answer 45

False

Question 46

It is a good practice to acquire ________________ wide enough to sufficiently provide for the ultimate expected development.

Answer 46

right of way

Question 47

It is a three-dimensional problem measured in x, y, and z coordinates.

Answer 47

alignment of a highway

Question 48

It is referred to as the plan view, which is roughly equivalent to the perspective of an aerial photo of the highway.

Answer 48

horizontal alignment of a highway

Question 49

It is represented in a profile view, which gives the elevation of all points measured along the length of the highway (again, with length measured along a constant elevation reference).

Answer 49

vertical alignment of a highway

Question 50

It specifies the elevation of points along a roadway.

Answer 50

Vertical alignment

Question 51

The primary concern of this is establishing the transition of roadway elevations between two grades.

Answer 51

Vertical alignment

Question 52

The transition of roadway elevations between two grades is achieved by means of __________.

Answer 52

vertical curve

Question 53

Vertical curves can be broadly classified into:

Answer 53

1. crest vertical curves 2. sag vertical curves

Question 54

In practice, the vast majority of vertical curves are arranged such that half of the curve length is positioned before the PVI and half after. Curves that satisfy the criterion are called __________________.

Answer 54

equal-tangent vertical curves

Question 55

True or False. One of the most critical concerns in the design of a highway is the provision of adequate driver sight distance to permit a safe stop.

Answer 55

True

Question 56

It is defined as that level of safety that gives drivers sufficient sight distance to allow them to safely stop their vehicles to avoid collisions with objects obstructing their forward motion.

Answer 56

Appropriate level of safety

Question 57

It differs from crest vertical curve design in the sense that sight distance is governed by nighttime conditions because in daylight, sight distance on a this is unrestricted.

Answer 57

Sag vertical curve

Question 58

What is the critical concern for sag vertical curve design?

Answer 58

the length of roadway illuminated by the vehicle headlights