Labsheet - Signalized Intersection Capacity and LOS

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE 1.0

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INTRODUCTION The capacity of a street is related primarily to the signal timing and the geometric characteristics of the facility as well as to the composition of traffic on the facility. Geometrics are a fixed characteristic of a facility. Thus, while traffic composition may vary somewhat over time, the capacity of a facility is generally a stable value that can be significantly improved only by initiating geometric improvements. At signalised intersections, the additional element of time allocation is introduced into the concept of capacity. A traffic signal essentially allocates time among conflicting traffic movements that seek to use the same space. The way in which time is allocated significantly affects the operation and the capacity of the intersection and its approaches. In analysing a signalised intersection, the physical unit of analysis is the lane group. A lane group consists of one or more lanes on an intersection approach. The outputs from application of the method in this manual are reported on the basis of each lane group. Capacity at intersections is defined for each lane group. The lane group capacity is the maximum hourly rate at which vehicles can reasonably be expected to pass through the intersection under prevailing traffic, roadway, and signalization conditions. Capacity is stated in vehicles per hour (veh/h). The level of service (LOS) at signalised intersections is expressed in terms of delay, which relate to control, geometrics, traffic and incidents. Stopped delay may be used to determine the LOS. It is defined as the time a vehicle waits at a traffic light. Stopped delay stated in seconds per vehicle (sec/veh).

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OBJECTIVE The objective is to determine the capacity and level of service of the UTHM signalised intersection using JKR Arahan Teknik (Jalan) 13/87 procedure.

Prepared by: Name: Dr Basil David Daniel Date: 1 September 2014

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE 3.0

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APPARATUS / EQUIPMENT 1. 2. 3. 4. 5. 6.

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Odometer / Measuring Wheel Stopwatch Analog Counter Safety Vest Safety Cones (optional) Flags (optional)

PROCEDURE 1. At the UTHM Signalised Intersection, conduct a traffic movement count on all approaches (each lane separately) for one hour in four segments of 15 minutes. Record the data in Tables 1 – 10. 2. Measure the lane widths, W (in meter) for all approaches and record the data in Table 11. 3. For each phase, measure the green time, g (sec) and cycle time, C (sec). Record the data in Table 12. 4. Convert traffic volumes recorded in Tables 1 – 10 to passenger car unit (p.c.u.). This is taken as the design flow, q (pcu/hr) which will then be used in Table 11. 5. Determine the adjusted saturation flow, S’ (pcu/hr) for each approach and transfer the values to Table 11. 6. Using Table 11, compute y, which is the ratio of design flow to adjusted saturation flow and determine the Y value, which is the total value of y for each approach. 7. Then, calculate the intergreen time, I (sec) and total lost time per cycle L (sec), 8. Determine the practical capacity, Yprac and reserve capacity, RC of the intersection. 9. Determine the average stopped delay per vehicle, d (sec) and level of service for each approach.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE 5.0

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DATA ANALYSIS Table 1 Approach (Movement): PARIT RAJA (RIGHT-TURN) Day/Date: __________________ Time: _____________ Time

Lane: 1 Weather: ____________

Traffic Count Vehicle Class 1

2

Vehicle Class

3

Traffic Volume (veh/hour)

Class 1 (Motorcycles) Class 2 (Cars) Class 3 (Vans & Medium Trucks) Class 4 (Heavy Trucks & Buses) Total (PR1) Note: p.c.u. = passenger car unit

4

p.c.u. Factor 0.33 1.00 1.75 2.25

p.c.u.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Table 2 Approach (Movement): PARIT RAJA (THROUGH) Day/Date: __________________ Time: _____________ Time

Lane: 2 Weather: ___________

Traffic Count Vehicle Class 1

2

Vehicle Class

3

Traffic Volume (veh/hour)

Class 1 (Motorcycles) Class 2 (Cars) Class 3 (Vans & Medium Trucks) Class 4 (Heavy Trucks & Buses) Total (PT2) Note: p.c.u. = passenger car unit

4

p.c.u. Factor 0.33 1.00 1.75 2.25

p.c.u.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Table 3 Approach (Movement): PARIT RAJA (THROUGH) Day/Date: __________________ Time: _____________ Time

Lane: 3 Weather: ___________

Traffic Count Vehicle Class 1

2

Vehicle Class

3

Traffic Volume (veh/hour)

Class 1 (Motorcycles) Class 2 (Cars) Class 3 (Vans & Medium Trucks) Class 4 (Heavy Trucks & Buses) Total (PT3) Note: p.c.u. = passenger car unit

4

p.c.u. Factor 0.33 1.00 1.75 2.25

p.c.u.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Table 4 Approach (Movement): PARIT RAJA (THROUGH) Day/Date: __________________ Time: _____________ Time

Lane: 4 Weather: ___________

Traffic Count Vehicle Class 1

2

Vehicle Class

3

Traffic Volume (veh/hour)

Class 1 (Motorcycles) Class 2 (Cars) Class 3 (Vans & Medium Trucks) Class 4 (Heavy Trucks & Buses) Total (PT4) Note: p.c.u. = passenger car unit

4

p.c.u. Factor 0.33 1.00 1.75 2.25

p.c.u.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Table 5 Approach (Movement): UTHM (RIGHT TURN) Lane: 1 Day/Date: __________________ Time: _____________ Weather: ___________ Time

Traffic Count Vehicle Class 1

2

Vehicle Class

3

Traffic Volume (veh/hour)

Class 1 (Motorcycles) Class 2 (Cars) Class 3 (Vans & Medium Trucks) Class 4 (Heavy Trucks & Buses) Total (UR1) Note: p.c.u. = passenger car unit

4

p.c.u. Factor 0.33 1.00 1.75 2.25

p.c.u.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Table 6 Approach (Movement): UTHM (RIGHT / LEFT TURN) Day/Date: __________________ Time: _____________ Time

Lane: 2 Weather: ___________

Traffic Count Vehicle Class 1

2

Vehicle Class

3

Traffic Volume (veh/hour)

Class 1 (Motorcycles) Class 2 (Cars) Class 3 (Vans & Medium Trucks) Class 4 (Heavy Trucks & Buses) Total (URL2) Note: p.c.u. = passenger car unit

4

p.c.u. Factor 0.33 1.00 1.75 2.25

p.c.u.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Table 7 Approach (Movement): BATU PAHAT (U-TURN) Day/Date: __________________ Time: _____________ Time

Lane: 1 Weather: ___________

Traffic Count Vehicle Class 1

2

Vehicle Class

3

Traffic Volume (veh/hour)

Class 1 (Motorcycles) Class 2 (Cars) Class 3 (Vans & Medium Trucks) Class 4 (Heavy Trucks & Buses) Total (BU1) Note: p.c.u. = passenger car unit

4

p.c.u. Factor 0.33 1.00 1.75 2.25

p.c.u.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Table 8 Approach (Movement): BATU PAHAT (THROUGH) Day/Date: __________________ Time: _____________ Time

Lane: 2 Weather: ___________

Traffic Count Vehicle Class 1

2

Vehicle Class

3

Traffic Volume (veh/hour)

Class 1 (Motorcycles) Class 2 (Cars) Class 3 (Vans & Medium Trucks) Class 4 (Heavy Trucks & Buses) Total (BT2) Note: p.c.u. = passenger car unit

4

p.c.u. Factor 0.33 1.00 1.75 2.25

p.c.u.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Table 9 Approach (Movement): BATU PAHAT (THROUGH) Day/Date: __________________ Time: _____________ Time

Lane: 3 Weather: ___________

Traffic Count Vehicle Class 1

2

Vehicle Class

3

Traffic Volume (veh/hour)

Class 1 (Motorcycles) Class 2 (Cars) Class 3 (Vans & Medium Trucks) Class 4 (Heavy Trucks & Buses) Total (BT3) Note: p.c.u. = passenger car unit

4

p.c.u. Factor 0.33 1.00 1.75 2.25

p.c.u.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Table 10 Approach (Movement): BATU PAHAT (LEFT-TURN) Day/Date: __________________ Time: _____________ Time

Lane: 4 Weather: ___________

Traffic Count Vehicle Class 1

2

Vehicle Class

3

Traffic Volume (veh/hour)

Class 1 (Motorcycles) Class 2 (Cars) Class 3 (Vans & Medium Trucks) Class 4 (Heavy Trucks & Buses) Total (BL4) Note: p.c.u. = passenger car unit

4

p.c.u. Factor 0.33 1.00 1.75 2.25

p.c.u.

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Table 11 Phase Movement W (m) S’ (pcu/hr) q (pcu/hr) y = q/S’ y

I PT2

PT3

PT4

II BT2

BT3

PT2

PT3

III PT4

PR1

PR1

IV BU1

Key: P = Parit Raja Approach; B = Batu Pahat Approach; U = UTHM Approach T = Through; R = Right-turn; L = Left-turn 1 = Lane 1; 2 = Lane 2; 3 = Lane 3; 4 = Lane 4 Example Calculation of Adjusted Saturation Flow, S’

Y = y1 + y2 + y3 + y4 = Amber time, a = All-red period, R = 2 sec Intergreen time, I = a + R = Drivers’ reaction time, l = 2 sec Number of phases, n = 4 Total lost time, L = n(I – a) + nl =

UR1

URL2

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Practical capacity, Yprac = 0.9 – 0.0075L =

Reserve capacity, RC = 100%  ( Yprac – Y ) / Y =

Table 12 Phase Movement C (sec) g (sec)

 = g/C S’ (pcu/hr) q (pcu/hr) qs(pcu/sec) x = q/S’ d (sec) LOS

I PT2

PT3

PT4

II BT2

BT3

PT2

PT3

III PT4

PR1

PR1

IV BU1

UR1

URL2

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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Example calculation for delay and determination of LOS

Sketch of UTHM Intersection

Sketch of Phase Diagram

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE 6.0

DISCUSSION Comment on the LOS of UTHM intersection.

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Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE 7.0

CONCLUSION

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Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE 8.0

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APPENDICES (A) Saturation Flow Estimation If W < 5.5 m, use the following table: W (m) S (pcu/hr)

3.0 1845

3.25 1860

3.5 1885

3.75 1915

4.0 1965

4.25 2075

4.5 2210

4.75 2375

5.0 2560

If W  5.5 m, use the equation S = 525W

(B) Saturation Flow Adjustment S’ = S  Fg  Fr  Fl  Ft Correction factor for the effect of gradient, Fg is taken as 1.00 for 0% gradient. Correction factor for the effect of turning radius, Ft Correction Factor, Ft 0.85 0.90 0.96

Description for turning radius R < 10 m for turning radius where 10 m < R < 15 m for turning radius where 15 m < R < 30 m

Correction factors for turning traffic, Fr and Fl % Turning Traffic 5 10 15 20 25 30 35 40 45 50 55 60

Factor for right-turn, Fr 0.96 0.93 0.90 0.87 0.84 0.82 0.79 0.77 0.75 0.73 0.71 0.69

Factor for left-turn, Fl 1.00 1.00 0.99 0.98 0.97 0.95 0.94 0.93 0.92 0.91 0.90 0.89

5.25 2760

Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE

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(C) Average Stopped Delay per Vehicle Average delay per vehicle, d on a particular intersection arm is given by the formula:

 9  C (1   )2 x2 d    10  2(1  x ) 2qs (1  x )  where C = cycle time (sec)  = proportion of the cycle that is effectively green for the phase = g/C qs = flow in pcu/sec x = degree of saturation = q/S’

(D) Level of Service Criteria for Signalised Intersection LEVEL OF SERVICE A B C D E F

DELAY PER VEHICLE < 5.0 seconds 5.1 to 15.0 seconds 15.1 to 25.0 seconds 25.1 to 40.0 seconds 40.1 to 60.0 seconds > 60.0 seconds

Source: JKR ATJ 13/87