powerpoint presentation (cabral)

8/2/2019 PowerPoint Presentation (Cabral)

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Christopher CabralGraduate StudentUMass Dartmouth

In partial fulfillment of the requirements for the CEN 519 course inAdvanced Traffic Engineering Spring Semester 2012


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Confusing Intersection (half signalized) Frequent Accidents

The North Attleborough Board of PublicWorks has addressed the need forimprovements

Proposed solutions appear to be costly andcomplex

The town BPW has not yet agreed upon anypermanent solutions


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Visually and quantitatively investigate theproblems of the intersection

Simulations using peak AM and PM trafficvolumes with VISSIM

Design alternatives that have not yet beenproposed

Use VISSIM to simulate the newly proposeddesign for peak AM and PM volumes


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YearNumber of

Accidents

Number of Vehicles

Involved in AccidentsInjuries

2006 15 30 4

2007 16 31 4

2008 17 35 3

Total 48 96 11

Accident Counts (2006-2008)


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To

FromRoute-1A NB Route-1 NB Elmwood St Route-1 SB Route-1A SB

Route-1A NB 20 60 160 260

Route-1 NB 5 70 715 175

Elmwood St 15 25 80 20

Route-1 SB 60 230 20 5

Route-1A SB 170 85 0 5

ToFrom Route-1A NB Route-1 NB Elmwood St Route-1 SB Route-1A SB

Route-1A NB 45 50 70 205

Route-1 NB 10 75 380 120

Elmwood St 80 80 30 25

Route-1 SB 205 735 50 5

Route-1A SB 405 145 50 55

Peak AM Volumes

Peak PM Volumes


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Cycle Length, C = 88 s Number of Phases, N=3


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Parameter Time (s)

l1 3.3

l2 4.5

tL 7.8hs 2.0

Start up Loss Time ( l1 )

Clearance Loss Time ( l2 )

Total Loss Time ( tL ) Saturation Headway ( hs )

Critical Lane Flow, Vc

Vc = 1,321 vph


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Measured Critical Volume= Max of [ (Route 1 NB + Route 1 NB LT) / 2 Lanes +(Route 1 SB + Route 1 SB LT) / 2 Lanes ] + Max of [(Route 1A (EB) + Route 1A (EB) RT) / 2 Lanes +

Elmwood St]

Measured Critical Volume (AM)= (Route 1 NB + Route 1 NB LT) / 2 + (Route 1A (EB) +Route 1A (EB) RT) / 2

= (785 + 180) / 2 + (225 + 105) / 2 = 648 vph

Measured Critical Volume (PM)= (Route 1 SB + Route 1 SB LT) / 2 + Elmwood St= (945 + 50) / 2 + 215 = 713 vph


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Direction Calculated

Maximums

Measured

Critical Lane-Flow AM PM

All Approaches 1,321 648 713

Approach Capacity

Route 1 NB 1,002 483 293

Route 1 SB 675 158 498

Route 1A (EB) 470 165 208

Elmwood St 470 140 215

Since the measured capacities of each individualapproach and total critical lane flow are less thanthe allowable maximums, the signal phasing andtiming sequence is not the main problem causing

traffic queuing and delays


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Insert movie clip of peak AM simulation oncurrent design


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Insert movie clip of peak PM simulation oncurrent design


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ApproachMean (s) Standard Dev 85% Confidence Bounds

for Mean Delay (s)LOS

Route 1 NB 6.0 0.6 5.6 6.4 A

Route 1 SB 3.1 0.7 2.6 3.5 ARoute 1A (EB) 71.0 10.9 64.0 78.0 E

Elmwood St 10.2 0.9 9.6 10.8 A - B

Peak AM Volumes

ApproachMean (s) Standard Dev 85% Confidence Bounds

for Mean Delay (s)LOS

Route 1 NB 3.4 0.6 3.0 3.8 A

Route 1 SB 64.1 16.3 53.6 74.6 D - E

Route 1A (EB) 104.1 18.1 92.4 115.8 E

Elmwood St 14.0 0.6 13.6 14.3 B

Peak PM Volumes


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BETA Group, Inc

Engineering consulting firm hired by NorthAttleborough to design potential solutions

The town has not yet made any decisions

Costly and complex proposals submitted so far

3 Alternatives

Require movement elimination, land acquisition,and/or new road construction


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Open up existing intersection Have traffic from all 5 directions apart of1

signalized intersection Based on approach volumes, 4 additional

lanes to be constructed

Limited area, but with proper curb and median

adjustments the added lanes can fit Right Turn lanes for Route 1 SB and Route 1A NB

Left Turn lanes for Route 1 NB and Route 1A SB

5 Phases


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ProtectedMovements

UnprotectedMovements


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Originally, each approach was given its ownphase

VISSIM showed long queuing and delay times

Then, Routes 1 and 1A straight movements weregiven a phase together

Majority of traffic through intersection

Phases for protected turning movements weregrouped together

Route 1 SB to Route 1A SB movement eliminated

Only 5 vph for both peak AM and PM traffic


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Route 1A SB,All Protected

Movements


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Routes 1 and1A, NB and SB,

StraightMovements Route 1 SB

UnprotectedLeft Turn


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Route 1 NB,All Protected

Movements


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Route 1 SB andRoute 1A NB,

ProtectedRight Turns


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Elmwood St,All Protected

Movements


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Cycle Length (s)

Total Available Green Time (s)

Phase

Max Vol.

(vph)

Design Use

(vph)

Cycle

Length (s)

Total Available

Green Time (s)

% of Total

Design Use (%)

Green Time

(s)

Design Green

(s)

1 170 90

80.0 50.0

9.9 4.945055 5.0

2 393 260 28.6 14.28571 14.0

3 393 180 19.8 9.89011 10.0

4 240 240 26.4 13.18681 13.0

5 140 140 15.4 7.692308 8.0

Total 1,123 910 100.0 50.0 50.0

Phase

Max Vol.

(vph)

Design Use

(vph)

Cycle

Length (s)

Total Available

Green Time (s)

% of Total

Design Use

Green Time

(s)

Design Green

(s)

1 405 250

120.0 90.0

20.9 18.82845 19.0

2 395 395 33.1 29.74895 30.0

3 228 130 10.9 9.790795 10.0

4 205 205 17.2 15.43933 15.0

5 215 215 18.0 16.19247 16.0

Total 1,448 1,195 100.0 90.0 90.0

PeakAM

PeakPM


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ApproachPhase

1 2 3 4 5

Route 1 NB

Straight

R

11

G

20

G

10

y

4

ar

2

R

19

R

14

Route 1 NB

Left

R

11

R

20

G

10

y

4

ar

2

R

19

R

14

Route 1 SB

Straight

R

11

G

14

y

4

R

2

R

16

R

19

R

14

Route 1 SB

Right

R

11

R

20

R

16

G

13

y

4

ar

2

R

14

Route 1A NB

Straight

R

11

G

14

y

4

R

2

R

16

R

19

R

14

Route 1A NB

Right

R

11

R

20

R

16

G

13

y

4

ar

2

R

14

Route 1A SB

Straight

G

11

G

14

y

4

R

2

R

16

R

19

R

14

Route 1A SB

Left

G

5

y

4

ar

2

R

20

R

16

R

19

R

14

Elmwood StR

11

R

20

R

16

R

19

G

8

y

4

ar

2

AM PMApproach

Phase

1 2 3 4 5

Route 1 NB

Straight

R

25

G

36

G

10

y

4

ar

2

R

21

R

22

Route 1 NB

Left

R

25

R

36

G

10

y

4

ar

2

R

21

R

22

Route 1 SB

Straight

R

25

G

30

y

4

R

2

R

16

R

21

R

22

Route 1 SB

Right

R

25

R

36

R

16

G

15

y

4

ar

2

R

22

Route 1A NB

Straight

R

25

G

30

y

4

R

2

R

16

R

21

R

22

Route 1A NB

Right

R

25

R

36

R

16

G

15

y

4

ar

2

R

22

Route 1A SB

Straight

G

25

G

30

y

4

R

2

R

16

R

21

R

22

Route 1A SB

Left

G

19

y

4

ar

2

R

36

R

16

R

21

R

22

Elmwood StR

25

R

36

R

16

R

21

G

16

y

4

ar

2

Cycle Length =80 s Cycle Length =120 s


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Insert movie clip of peak AM simulation onnew design


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Insert movie clip of peak PM simulation onnew design


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Approach Proposed DesignDelay (s)

LOS Existing DesignDelay (s)

LOS

Route 1 NB Straight 6.7 12.6 A - B5.6 6.4 A

Route 1 NB Left 13.4 14.8 B

Route 1 SB Straight 10.6 12.1 B2.6 3.5 A

Route 1 SB Right 4.3 6.5 A

Route 1A NB Straight 19.4 21.2 B - C

64.0 78.0 ERoute 1A NB Right 17.8 20.1 B - C

Route 1A SB Straight 8.3 10.4 A - B

Route 1A SB Left 20.5 24.9 C

Elmwood St 16.2 18.8 B 9.6 10.8 A - B

ApproachProposed Design

Delay (s)LOS

Existing Design

Delay (s)LOS

Route 1 NB Straight 18.2 19.5 B

3.0 3.8 ARoute 1 NB Left 26.6 32.5 C

Route 1 SB Straight 43.8 47.2 D53.6 74.6 D - E

Route 1 SB Right 48.2 55.5 D

Route 1A NB Straight 21.6 23.2 C - C

92.4 115.8 ERoute 1A NB Right 27.6 36.0 C - D

Route 1A SB Straight 33.9 38.0 C - D

Route 1A SB Left 72.9 76.9 EElmwood St 35.1 39.2 D 13.6 14.3 B

PeakAM

Peak

PM


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New proposal evenly distributes delay timesand improves traffic operations

Not as complex and expensive compared to

other alternatives Proper curb and median adjustments can

allow for the additional lanes in this design to

fit within the already limited area Potential solution to minimizing accidents,

driver confusion, delays and queuing


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Maximum fixed green times analyzed Traffic Engineer will have to determine proper

Minimum green times as well as vehicle extension

times for Detectors Pedestrian phase neglected

Pedestrian button to be installed if designimplemented

Route 1 SB to Route 1A SB movementeliminated/sacrificed

Only 5 vph during both peak AM and PM volumes

Pavement markers - safely direct traffic


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Intersection Design. Massachusetts Highway Department, 2006. Cabral, Steven P.E. Crossman Engineering, Inc. Town of North Attleborough Board of Public

Works. 2012 Chaudhary, N., C. Chu, S. Sunkari, and K. Balke. Guidelines for Operating Congest Traffic

Signals. Texas Transportation Institute, 2010. DeGray, Jason. BETA Group, Inc. 2012 DeMelia, A. At a Dead End - Proposals to Fix Busy North Intersection Proving Complicated and

Costly. Sun Chronicle, Vol. News, No.http://www.thesunchronicle.com/articles/2012/02/14/news/10969045.txt , 2012.

Google Inc. Google Earth. , Vol. 5.1.3533.1731, 2009. Last, M., G. Avrahami, and A. Kandel. Using Data Mining Techniques for Optimizing Traffic

Signal Plans at an Urban Intersection. International Journal of Intelligent Systems, Vol. 26, No. 7,2011, pp. 603-620.

Massachusetts Highway Department. Project Development and Design Guide.http://www.vhb.com/mhdGuide/mhd_Guidebook.asp , Accessed February, 2012.

MassDOT. Average Crash Rates.

http://www.mhd.state.ma.us/default.asp?pgid=content/traffic/crashrate&sid=about , AccessedFebruary, 2012.

McShane, W., E. Prassas, and R. Proses. Traffic Engineering. Pearson, New Jersey, 2011.NCHRP. Evaluating Intersection Improvements: An Engineering Study Guide. Transportation Research

Board, National Research Council, 2001. PTV Vision. VISSIM. , Vol. 5.3, 2010.
http://www.thesunchronicle.com/articles/2012/02/14/news/10969045.txthttp://www.thesunchronicle.com/articles/2012/02/14/news/10969045.txthttp://www.vhb.com/mhdGuide/mhd_Guidebook.asphttp://www.vhb.com/mhdGuide/mhd_Guidebook.asphttp://www.mhd.state.ma.us/default.asp?pgid=content/traffic/crashrate&sid=abouthttp://www.mhd.state.ma.us/default.asp?pgid=content/traffic/crashrate&sid=abouthttp://www.mhd.state.ma.us/default.asp?pgid=content/traffic/crashrate&sid=abouthttp://www.vhb.com/mhdGuide/mhd_Guidebook.asphttp://www.thesunchronicle.com/articles/2012/02/14/news/10969045.txt


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