Name ______________________________________________

Name ___________________________ Transportation Engg. Finals Score______

A. SOLVE THE FOLLOWING:1. Given the basic system, if major path is a-c, draw the reduced system. b

c a2. Given the basic system, draw the reduced system as major path is b-d. b c

a d

3. Given the basic system, draw the reduced system as major path is c- d. b

ce

f

d a4. Draw and determine the maximum number of conflict points in a 4-leg intersection if one of its leg has one-way traffic. 5. Draw and determine the number of conflict points in a three-leg T-intersection if the straight road does not permit any left turn. 6. Draw and determine the maximum number of conflict points in a 4-leg intersection if two opposing legs both do not permit left turn direction.

7. Traffic volume of a four-leg intersection is shown in the table. It is supposed to be replaced by a roundabout with the width of the weaving lane is 10.50 m, average width of the entries = 7.50 m, and the length of the weaving section is 45 m. (Use = 0.85). Determine: a) the critical volume,

b) the capacity of the roundabout

c) the reserved capacity in percentage

d) number of years the roundabout will operate until V/C ratio = 1 if traffic growth rate is 0.5% per 3 months. e) the radius of central island EntryRight TurnStraightLeft TurnTotal

N200465215880

S300100315715

E125200125450

W175230350755

Part I- True or False

_____1. Intersections maybe categorized according to shape, type of structure and volume of traffic.

_____2. Good intersection must be limited to 5 leg intersection.

_____3. Staggered intersection should be avoided.

_____4. Main traffic in an intersection should flow near perpendicular as possible.

_____5. Roads should intersect at an angle close to right angle as possible.

_____6. Roundabout has the same number of conflict points as the regular intersection.

_____7. A 4-leg regular intersection has a maximum of 16 crossing conflict points

_____8. A 4-leg regular intersection has a maximum of 6 diverging conflict points.

_____9. A 3-leg T-intersection has 2 diverging conflict points.

_____10. A 3-leg T- intersection has 3 crossing conflict points.

Part II-

Given the traffic flow. Determine the cycle time if starting loss = 2 sec and red time = 2 sec. Calculate the degree of congestion. Draw the signal timing diagram.

ApproachDirectionTotal Volume

Pcu/hr.Sat. Flow Rate

Pcu/hr

EThrough

Left 493

1852400

1700

WThrough

Left 287

2932400

1700

NThrough

Left 340

2472200

1800

SThrough

Left508

2652200

1800

PHASING

A

SHAPE \* MERGEFORMAT

B SHAPE \* MERGEFORMAT

C SHAPE \* MERGEFORMAT

D SHAPE \* MERGEFORMAT

Part III.

Traffic volume of a four-leg intersection is shown in the table. It is supposed to be replaced by a roundabout with the width of the weaving lane is 10.50 m, average width of the entries = 7.50 m, and the length of the weaving section is 45 m. (Use = 0.85). Determine:

a) the critical volume,

b) the capacity of the roundabout

c) the reserved capacity in percentage

d) number of years the roundabout will operate until V/C ratio = 1 if traffic growth rate is 1.5% per annum.

e) the radius of central island

EntryRight TurnStraightLeft TurnTotal

N200465215880

S300100315715

E125200125450

W175230350755

Part IV. For each approach of the intersection, allocate lanes for through and left and design appropriate phasing so that the degree of congestion does not exceed 0.90. Draw the intersection showing the number of lanes allocated for each approach and direction.

PHASING

AB

C

D

PhaseApproachDirection Total Vol.

Pcu/hr.SFR

Pcu/hr/laneNo. of lanes allocated

A

E

WW

E1353

12902200

2200

BW

EN

S621

3921800

1800

CN

SS

N1298

19342100

2100

DN

SE

W466

2501700

1700

Part V-

Discuss the significance of traffic impact assessment of any future infrastructure development like malls or business establishments in order to avoid traffic problems that may be caused by the said developments.