Operational Effects of Geometric Design

Question 1

What is the minimum loop ramp design speed for highways with a design speed greater than 50 mph (80 km/h)?

Answer 1

20 mph (30 km/h)

Question 2

Superelevation transition is?

Answer 2

The sum of tangent runout and superelevation runoff

Question 3

A ball-bank indicator reading of 10 degrees suggest an advisory speed of

Answer 3

30 to 50 mph (55 to 80 km/h)

Question 4

What is the recommended ramp spacing in urban areas?

Answer 4

1 mile

Question 5

What is the perception-reaction time used in calculating the decision sight distance needed to stop on an urban road?

Answer 5

9.1 sec

Question 6

How many warrants should be considered to decide if a grade separation or interchange is justified at an existing site?

Answer 6

6

Question 7

What is the desirable minimum grade on a curved road to facilitate surface drainage?

Answer 7

0.5%

Question 8

For overhead sign supports, what is the minimum lateral offset from the edge of the shoulder?

Answer 8

6 ft

Question 9

How many vehicle classes are defined by FHWA?

Answer 9

13

Question 10

How many design vehicles are defined by AASHTO?

Answer 10

19

Question 11

Design vehicle for freeway interchange ramp

Answer 11

WB-67

Question 12

According to AASHTO, most common design speed for rural freeway

Answer 12

70 mph

Question 13

Stopping sight distance calculated based on truck driver’s eye height when an underpass is present.

Answer 13

8ft

Question 14

What safety measure is recommended when considering maximum superelevation rate greater than 12%?

Answer 14

Use spiral curve transition between approach tangent and horizontal curve.

Question 15

Maximum superelevation rate on roads with upgrades of 4% or greater and design speeds of 55 mph or higher?

Answer 15

9%

Question 16

On horizontal curves, a maximum superelevation rate of 12% can be used when

Answer 16

The available sight distance exceeds the stopping sight distance

Question 17

What is the maximum grade on mountainous terrain for rural freeways with design speed of 70 mph (110 km/hr)?

Answer 17

5%

Question 18

Desirable minimum grade on curved road to facilitate surface drainage

Answer 18

0.5%

Question 19

Minimum grade on a curved road to facilitate surface drainage

Answer 19

0.3%

Question 20

Recommended minimum vertical clearance at-grade separated location.

Answer 20

14.5 ft (4.4m)

Question 21

Median width is defined as the dimension between.

Answer 21

The edges of the traveled way for the roadways in opposing directions of travel, including the width of the left shoulders.

Question 22

Maximum superelevation rate on roadways where ice and snow are factors?

Answer 22

8%

Question 23

Sharp horizontal curves on downgrades of 4% or more should not be designed for design speeds of?

Answer 23

30 MPH

Question 24

Factors important in roadside crash cushion selection

Answer 24

Site characteristics
Maintenance
Road functional class

Question 25

Desirable clear zone width for low speed rural collectors

Answer 25

7 to 10 ft

Question 26

Essential freeway elements

Answer 26

Ramp Median Clear zone

Question 27

Factor controlling profile of a rural freeway

Answer 27

Fill material and soil condition

Question 28

How many warrants for grade separation or interchange at an existing site?

Answer 28

6

Question 29

Grade separation or interchange warrant

Answer 29

Design designation Site topography Reduced congestion

Question 30

Interchange that eliminates weaving associated with full clover leaf design

Answer 30

Partial cloverleaf

Question 31

Ramp spacing in rural areas

Answer 31

2 miles

Question 32

Benefit of depressed freeway

Answer 32

Permitting surface streets to cross at their normal grade and reduce freeway noise

Question 33

Interchange classified as compressed diamond when distance between two intersections is

Answer 33

400-800 ft

Question 34

Interchange classified as tight diamond when distance between two intersections is

Answer 34

250-400 ft

Question 35

Configuration removes yielding condition from connecting roadway between two roundabouts

Answer 35

Raindrop

Question 36

Part of sidewalk located between pedestrian and edge zone

Answer 36

Furniture zone

Question 37

Vision component interferes with road user's decision in overtaking another vehicle against opposing traffic

Answer 37

Depth perception

Question 38

Example of driver's short term expectancy

Answer 38

Vehicle location of adjacent vehicle in next moment

Question 39

Perception reaction time used in calculating decision sight distance to stop on rural road?

Answer 39

3 seconds

Question 40

Perception reaction time used in calculating decision sight distance to stop on urban road?

Answer 40

9.1 seconds

Question 41

Purposes for developing single exits

Answer 41

Provide high speed exit from main roadway for all exiting traffic Simplify signing and decision process Satisfy driver expectancy placing exit in advance

Question 42

Maximum algebraic difference in traveled way and shoulder grade

Answer 42

7%

Question 43

Minimum lateral offset between curb face and utility poles on all streets?

Answer 43

1.5 ft

Question 44

Intersection design elements

Answer 44

Perception-reaction distance Queue storage distance Deceleration distance

Question 45

Minimum peak hour right turning volume required for adding right turn lane at intersection?

Answer 45

300 vph

Question 46

Minimum loop ramp design speed for highways with design speed greater than 50 mph?

Answer 46

20 mph