traffic survey and forecast of east intercahnge in ulanbaatar

CHAPTER 3 TRAFFIC SURVEY AND FORECAST

3-1


There are approximate traffic forecast, direct demand model and 4 step approach

method in traffic forecast. The Consultant forecasted the future traffic with past

trend extension method of approximate traffic forecast because the project area

is small (only one intersection), project period is short and the survey data of OD

(Origin-Destination) for each traffic zones was insufficient. The traffic forecast

for each direction on the most concentrated traffic time of 2031 was forecasted

with present condition.

3.1 Traffic Forecasting Method

There are approximate traffic forecast, direct demand model and 4 step approach

method in traffic forecast. Approximate traffic forecast is used for the small area

or when the collect of data is difficult and it has past trend extension method and

demand flexibility method. Direct demand model and 4 step approach method

are used for accurate forecast in large scaled area.

The project area is small (only one intersection) and the survey data of traffic

pattern and OD (Origin-Destination) for each traffic zone was insufficient, so the

Consultant applied future traffic with past trend extension method of

approximate traffic forecast.

Based on the colleting result of the traffic demand forecast case for UB city, 4

step approach method was used in Detailed engineering design of road from

Yarmag bridge to Bayanzurh in Ulaanbaatar city", so reviewed it first.

3.1.1 Review the demand in Detailed engineering design of road from Yarmag

bridge to Bayanzurh in Ulaanbaatar city"


3-2

4 step approach method dividing the forecasted OD (Origin-Destination) volume

after organizing the road network under the reflection of the social-economic

index forecast and related plans was applied.

- Present O/D settlement: Settlement by the calibration process which repeatedly

distributes the O/D which was forecasted based on the detailed regional

population data on the present road network.

- Network settlement: The feasible planned road network on present road

network was reflected.

- Future O/D settlement: Settlement by calibration after the multiply of the

growth rate on the already settled present O/D traffic volume.

4 step approach method


3-3

Ulaanbaatar city is organized with six Districts such as Sukhbaatar, Khan-Uul,

Bayangol, Bayanzurkh, Songino Khairkhan and Chingeltei. Each Dirstict is

organized 14~25 Khoroo, and there are totally 120 Khorooes. East 4 road

intersection which is the project area is included in the Bayanzurkh District.

UB Districts in Study Area

S. No. Name of District No. of Blocks (Khoroos)

1 Bayangol 20

2 Chingeltei 19

3 Sukhbaatar 18

4 Bayanzurkh 24

5 Khan Uul 14

6 Songino Khairkhan 25

Total 120

Source: Data from Ulaanbaatar city government

Section map of traffic zone


3-4

Based on the review in the allocated traffic volume of Detailed engineering design

of road from Yarmag bridge to Bayanzurh in Ulaanbaatar city", there is big

difference in the project route with the OD and allocated traffic volume to

downtown because the project route is passing through the southern outer area

of UB city. The traffic volume of south-north direction of East 4 Road

Intersection in 2031 (Target year) was forecasted as below 1,000 vehicles per

hour. So, the use of the 4 step approach method and traffic data of Detailed

engineering design of road from Yarmag bridge to Bayanzurh in Ulaanbaatar

city" is insufficient.

3.1.2 Traffic forecast using past trend extension method

Traffic volume increasing rate was established as 1.35% after review of the past

traffic survey data of UB city and the bus terminal traffic data of The Study on

UB city Master Plan and Urban Development Program (JICA, 2006) and the

traffic data which the Consultant surveyed for the same area at 2008 was also

reviewed.

3.2 Present condition of traffic

The present traffic conditions such as geometric structure, traffic volume,

walkers volume, traffic sign time, etc were investigated and analyzed and were

used as the basic data for alternative design establishment and selection.

3.2.1 Traffic Survey

Traffic surveys of traffic index such the number of lanes, lane operation, traffic

sign operation, etc to check the accurate traffic conditions of East 4 road

intersection have been implemented Oct. 2008.

Traffic Survey Item


3-5

Item Contents

Geometry Number of Lanes, lane operation, Road width

Traffic Volume The vehicle types were classified as five (motor car, micro bus, general bus, small truck and large truck) and the traffic volume

by time and direction was investigated.

Pedestrian Volume Traffic volume of one hour on each fifteen minute from each direction

Signal Operation Traffic signal phase, and cycle length and location of traffic signal

Survey Site

3.2.2 Geometry

The Consultant investigated the road alignment, number of lanes and width of

each intersection approach, width of sidewalk and location of the bus stop to

check the traffic features of East 4 roads intersection.

Unsignalized Intersection of Westbound Approach


3-6

Bus Stop and Pedestrian Cross at Eastbound Approach


3-7

Geometry


3-8

3.2.3 Traffic Volume

1) Total volume on the intersection

Based on the traffic survey on the East 4 roads intersection for 14 hours, it

was found that the total volume on the intersection was increased quickly

after 08:00 and continued until after 20:00. The most concentrated traffic jam

time was from 09:00 to 10:00 and the traffic volume was 6,239 pcu/hr. The

traffic rates by vehicle type were investigated to be motor car 77%, bus 16%

and truck 7%.

Intersection Hourly Volume

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

6-7

7-8

8-9

9-10

10-11

11-12

12-13

13-14

14-15

15-16

16-17

17-18

18-19

19-20

Time

Vehicles(pcu/hr)

Volume Ratio by Vehicle Classification

Auto77%

MicroBUS13%

GeneralBUS3%

Truck7%

Auto73%

MicroBUS18%

GeneralBUS4%

Truck5%


3-9

2) Traffic volume by direction

The traffic volume by direction from 09:00 to 10:00 which was the most

concentrated traffic jam time among 14 hours of survey is as below.

Traffic volume by each direction

14-hrs Volume Peak Hour Volume

Peak Hour Traffic volume and vehicle type rate for each

approach

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Volume(veh/hr)

SB WB NB EB

Approach

Truck

GeneralBUS

MicroBUS

Auto


3-10

3) Delay and LOS analysis

The result of the calculation for the delay on the intersection by Synchro is

116.8sec/veh, LOS F. The service level for all approach to the intersection is F and

the delay from all approach was reported, and the delay especially occurred mainly

on left turn traffic system.

The delay will be relieved due to the signal time increase according to the

installment of overpass on the left turn of east-west direction. The left turn lane

increase is needed for the left turn of south-north direction.

Analysis result of intersection traffic movement

Approach Movement Volume

(pcu/hr)

Movement

Delay

(sec/veh)

Approach

Delay

(sec/veh),

LOS

Intersection

Delay

(sec/veh),

LOS

East Bound

Left Turn 265 246.4

102.8

(F)

116.8

(F)

Through 865 89.9

Right Turn 288 9.2

West Bound

Left Turn 495 212.0

136.7

(F) Through 997 149.6

Right Turn 415 15.8

North Bound

Left Turn 393 152.4

85.8

(F) Through 765 71.9

Right Turn 237 20.2

South Bound

Left Turn 428 192.4

133.5

(F) Through 907 129.2

Right Turn 184 17.5


3-11

3.2.4 Pedestrian Volume

The Consultant surveyed the volume of pedestrians crossing the intersection and

the volume of pedestrians on the sidewalk of Peace Avenue. LOS of Pedestrian

Crossing is C (moderate condition) and LOS of Sidewalk is A (good

condition).

Survey points for pedestrian volume

Pedestrian volume and LOS

Location Pedestrian Volume

(person/15min)

Effective Green Time for Pedestrian (sec)

Pedestrian Delay

(sec/person) LOS

Pedestrian Crossing

1 148 34 26.3 C

2 19 31 28.3 C

3 25 34 26.3 C

4 25 31 28.3 C

Location Pedestrian Volume

(person/15min) Effective Length of Sidewalk(m)

Flow Rate (person/min/m)

LOS

Sidewalk

5 179 2.0 6.0 A

6 23 2.0 0.8 A

7 157 2.0 5.2 A

8 27 2.0 0.9 A


3-12

3.2.5 Traffic Signal Operation

The signal for east 4 road intersection is operating as pre-timed signal on 110

second cycle length. The design review of signal time connected with ITS will

be needed because there is the ITS plan to change the signal controller unit for

the intersection which is under examination of the design proposal.

Traffic signal location

4

22

2

4

2

34

2

2

2

42

44

2

4

2

32

2

2

2

4

2

3

2

Signal Operation

Phase and Signal Time Signal Operation

15

1

(3)

2 3

31(3) 24(3)

Cycle

110

(sec)

4

28(3)

Phase Scheme : Dual Ring

Phase Sequence : Leading Left Turn

Cycle Length : 110 sec

Number of Phases : 4

Overlap Phase : No


3-13

3.3 Traffic forecast of the intersection in 2031

Daily volume of the East 4 road intersection of UB city is forecasted as 101,168

pcu/14hrs in 2031 which is the target year. The forecasted Peak

Hour(09:00~10:00) volume is converted as directional volume based on the

traffic rate of survey of Oct. 2008.

Forecasted hourly traffic volume in 2031

Time 2008 Hourly Volume

(pcu/hr) Volume Ratio

2031 Hourly Volume (pcu/hr)

06:00~07:00 714 0.0096 972

07:00~08:00 2,939 0.0396 4,001

08:00~09:00 5,767 0.0776 7,851

09:00~10:00 6,239 0.0840 8,494

10:00~11:00 6,136 0.0826 8,354

11:00~12:00 6,118 0.0823 8,329

12:00~13:00 6,172 0.0831 8,403

13:00~14:00 5,995 0.0807 8,162

14:00~15:00 5,860 0.0789 7,978

15:00~16:00 5,865 0.0789 7,985

16:00~17:00 5,811 0.0782 7,911

17:00~18:00 5,685 0.0765 7,740

18:00~19:00 5,439 0.0732 7,405

19:00~20:00 5,570 0.0750 7,583

Total 74,310 1.0000 101,168


3-14

The allocated traffic volume is calculated for each movement of approach to the

intersection by traffic forecast. The present traffic rate is applied for the traffic

rate of the movement. The peak hour is settled as 09:00~10:00 for A.M. based

on present traffic volume.

Intersection Volume in 2031

Movement AM Peak Hour(09:00~10:00)

Volume

(pcu/hr) Ratio

SB

RT 251 0.0296

TH 1,235 0.1454

LT 583 0.0686

WB

RT 565 0.0665

TH 1,356 0.1596

LT 674 0.0794

NB

RT 323 0.0380

TH 1,041 0.1226

LT 535 0.0630

EB

RT 392 0.0462

TH 1,178 0.1387

LT 361 0.0425

Total 8,494 1.0000

NB : North Bound, SB : South Bound, EB : East Bound, WB : West Bound LT : Left Turn, TH : Through, RT : Right Turn

traffic survey and forecast of east intercahnge in ulanbaatar

Documents