Modelling Speeds of Arterial Weaving Sections in Metro Manila...Non-weaving Speed: ( /3600) 3 b4 b5Va Unw b Ua e = − Unw-average speed of non-weaving vehicles, m/s Ua-average speed

Modelling Speeds of Arterial Weaving Sections in Metro Manila

ATRF 2009ATRF 2009Auckland, New ZealandSeptember 29, 2009

Ronald John GalizaSchool of Civil EngineeringUniversity of Queensland

Outline

• Problem Motivation

• Review of Existing Methods

• Survey Methodology

2

• Survey Methodology

• Results and Discussions

• Conclusions

• Recommendations

Signalized Intersections (before)

3

After Closure DLT from Arterial

4

•Left-turn from signalized intersection

•Left-turn diversion to U-turn plus right-turn (UTRT)

Through from Side Street

5

•Through movement at signalized intersection

•Through diversion to right-turn plus U-turn plus right-turn (RTUTRT)

Left-Turn from Side Street

6

•Left-turn movement at signalized intersection

•Left-turn diversion to right-turn plus U-turn (RTUT)

Weaving Areas Formed

7

Definition of a Weaving Area

�crossing of two or more traffic streams

traveling in the same general direction

without the aid of traffic control devices

(HCM 2000)

8

(HCM 2000)

Weaving Section in an Arterial

Exit Road (U-turn)

� Freeway 2-sided

weaving section…A

B

C

D

9

A

B

C

D

Minor Road (Driveway)

Exit Road (U-turn)

�The HCM Type C (2-sided) weaving configuration best describes arterial weaving…

Arterial weaving section… �

B

Capacity at Weaving Section

Flow Rate, q

Density, k

skuq =

10

Density, k

Speed, u

�Densities and speeds are difficult to determine w/o proper equipment.

Messer & Bonneson’s Ramp Weave Model (NCHRP Web Doc 12)

11

Ramp weave on arterial cross streets in interchange areas

Ramp Weave Model’s Weaving Path

C

�Path B – C

12

B

�Path B – C

Ramp Weave Model’s Non-weaving Paths

C

D

�Path A – C

�Path A – D

13

A

B

D �Path A – D

�Path B – D

Ramp Weave Models)3600/)1(( 21 wU VPbb

aow eUbU−−

=Weaving Speed:

Uw - average speed of weaving vehicles, m/s

Ua - average speed of entering vehicles, m/s

14

Ua - average speed of entering vehicles, m/s

Pu - probability of a weaving vehicle being unblocked

Vw - weaving flow rate, vph

21 ,, bbbo - regression coefficients

Ramp Weave Models

Non-weaving Speed:)3600/(

354 aVbb

anw eUbU−

=

Unw - average speed of non-weaving vehicles, m/s

Ua - average speed of entering vehicles, m/s

15

Ua - average speed of entering vehicles, m/s

Va - arterial flow rate, vph

543 ,, bbb - regression coefficients

�The weaving and non-weaving speed models need to be calibrated to get coefficients.

Survey Methodology

• Data collected using video recording stationed high vantage point;

• Recorded videos converted into digital

16

• Recorded videos converted into digital format;

• Data were extracted by repeated viewing of the recording on a computer.

Site Selection

• Must have three or more lanes in each direction

• Traffic volume on the driveway should be relatively high

17

be relatively high

• Weaving length should be less than 305 m

• Presence of signalized intersections within the vicinity should be minimal

Site 1 (Banaue – Quezon Ave)

18

Site 1: Banaue –Quezon Ave

Site 2 (Scout Borromeo-Quezon Ave.)

19

Site 2: Scout Borromeo –Quezon Ave

Model SummaryRegression coefficients

Site 1 Site 2

Weaving Model

bo 3.1140 1.8363

b1 0.4675 0.5418

b2 4.7944 0.6163

Weaving & Nonweaving Speed Models

(Site 1 vs Site 2 Model)

4.000

6.000

8.000

10.000

12.000

Sp

ee

d,

m/s

Site 2 - W

Site 1 - W

Site 2 - NW

Site 1 - NW

Ua = 10.0 m/s

SL = 1700 pcphpl

20

)3600/)1(( 21 wU VPbb

aow eUbU−−

=Weaving Speed:

Non-weaving Speed:)3600/(

354 aVbb

anw eUbU−

=

b2 4.7944 0.6163

non-weaving

Model

b3 3.0603 4.2738

b4 0.5261 0.4253

b5 0.3339 0.5568

0.000

2.000

Va20

050

080

011

0014

0017

0020

0023

0026

0029

00

Arterial Flow Rate, pcph

Sp

ee

d,

m/s

SL = 1700 pcphpl

Nt = 4

Vw = 350 pcph

lL = 0

Site 1 and 2 Calibration Results

Site 1 manoeuvre speed model statistics

Maneuver Speed

Model

Observations Root Mean Square Error R2

Weaving 35 0.490 m/s 0.44997 LARGE

21

non-weaving 35 0.447 m/s 0.54191 VERY LARGE

Site 2 manoeuvre speed model statistics

Maneuver Speed

Model

Observations Root Mean Square Error R2

Weaving 18 0.444 m/s 0.44019

non-weaving 18 0.425 m/s 0.66295

LARGE

VERY LARGE

Site 1 Model Testing

Parity Plot Site 1 Weaving (Testing)

y = 0.4516x + 3.2301

R2 = 0.45017.00

8.00

Pre

dic

ted

, m

/s

Parity Plot Site 1 Nonweaving (Testing)

y = 0.5335x + 3.5985

R2 = 0.5428.000

9.000

Pre

dic

ted

, m

/s

22

4.00

5.00

6.00

4.00 5.00 6.00 7.00 8.00

Observed, m/s

Pre

dic

ted

, m

/s

5.000

6.000

7.000

5.000 6.000 7.000 8.000 9.000

Observed, m/s

Pre

dic

ted

, m

/s

Site 1 Validation

Parity Plots (Validation Data)

y = 0.4006x + 3.4678

R2 = 0.43997.000

8.000

Pre

dic

ted

, m

/s

Parity Plot Site 1 Nonw eaving (Validation)

y = 0.4948x + 3.9681

R2 = 0.4718.000

9.000

Pre

dic

ted

, m

/s

23

4.000

5.000

6.000

4.000 5.000 6.000 7.000 8.000

Observed, m/s

Pre

dic

ted

, m

/s

5.000

6.000

7.000

5.000 6.000 7.000 8.000 9.000

Observed, m/s

Pre

dic

ted

, m

/s

Site 1 Summary

Model Process

Maneuver

Type Comparison Correlation t-test Goodness-of-fit

Site 1

TestingWeaving Obs - Pred OK

OK LARGE

Non-

weaving Obs - Pred

OK OK VERY LARGE

24

Site 1 weaving Obs - Pred

Validation Weaving Obs - Pred OK OK LARGE

Non-

weaving Obs - Pred

OK OK LARGE

Site 2 Model Testing

Parity Plot Site 2 Weaving (Testing)

y = 0.4303x + 3.4524

R2 = 0.4405

6.000

6.500

7.000

7.500

8.000

Pre

dic

ted

, m

/s

Parity Plot Site 2 Nonweaving (Testing)

y = 0.6613x + 2.7438

R2 = 0.6629

8.000

9.000

10.000

Pre

dic

ted

, m

/s

25

4.000

4.500

5.000

5.500

6.000

4.000 5.000 6.000 7.000 8.000

Observed, m/s

Pre

dic

ted

, m

/s

5.000

6.000

7.000

5.000 6.000 7.000 8.000 9.000 10.000

Observed, m/s

Pre

dic

ted

, m

/s

Site 2 Validation

Parity Plot Site 2 Weaving (Validation)

y = 0.3938x + 3.6832

R2 = 0.61997.000

8.000

Pre

dic

ted

, m

/s

Parity Plot Site 2 Nonweaving (Validation)

y = 0.3834x + 4.9606

R2 = 0.3956

7.000

8.000

9.000

10.000

Pre

dic

ted

, m

/s

26

5.000

6.000

5.000 6.000 7.000 8.000

Observed, m/s

Pre

dic

ted

, m

/s

5.000

6.000

7.000

5.000 6.000 7.000 8.000 9.000 10.000

Observed, m/s

Pre

dic

ted

, m

/s

Site 2 Summary

Model Process Maneuver Type Comparison Correlation t-test Goodness-of-fit

Site 2

Testing Weaving Obs - Pred OK OK LARGE

non-weaving Obs - Pred OK OK VERY LARGE

Validation Weaving Obs - Pred OK OK VERY LARGE

non-weaving Obs - Pred OK OK LARGE

27

Conclusions

�Ramp Weave Models

• Arterial and weaving flow rates affect weaving and non-weaving speeds.

• Weaving and non-weaving speeds decrease

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• Weaving and non-weaving speeds decrease as the arterial flow rate increases.

• Weaving and non-weaving speeds decrease with increased weaving flow rates.

• Weaving speeds are lower than non-weaving speeds.

Conclusions

• Approach speeds are higher than non-weaving speeds.

• Weaving length significantly affects the weaving speed.

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weaving speed.

• Shorter weaving length yields lower weaving speeds.

• The models developed can accurately predict weaving and non-weaving speeds.

Recommendations

• More extensive data collection from other sites.

• Incorporate weaving length in the

30

• Incorporate weaving length in the models.

• Use computer simulation to evaluate the speeds.

• Identify and develop a LOS criteria.

�Questions

�Comments

That ends the presentation… Thank you for listening…

31

�Comments

�Discussion

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