Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE 1.0 Page 1/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 INTRODUCTION The capacity of a street is related primarily to the signal timing and the geome tric 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 composi tion 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 introd uced 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 allo cated 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 lan e group. A lane group consists of one or more lanes on an intersection approach. The outp uts 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 capacit y is the maximum hourly rate at which vehicles can reasonably be expected to pass thr ough 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 vehi
cle waits at a traffic light. Stopped delay stated in seconds per vehicle (sec/veh). 2.0 OBJECTIVE The objective is to determine the capacity and level of service of the UTHM sign alised 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 2/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 APPARATUS / EQUIPMENT 1. 2. 3. 4. 5. 6. 4.0 Page 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). Reco rd 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 trans fer 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 eac
h 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 Page 3/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Class Class Class Total Note:
1 (Motorcycles) 2 (Cars) 3 (Vans & Medium Trucks) 4 (Heavy Trucks & Buses) (PR1) 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 Page 4/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Class Class Class Total Note:
1 (Motorcycles) 2 (Cars) 3 (Vans & Medium Trucks) 4 (Heavy Trucks & Buses) (PT2) 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 Page 5/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Class Class Class Total Note:
1 (Motorcycles) 2 (Cars) 3 (Vans & Medium Trucks) 4 (Heavy Trucks & Buses) (PT3) 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 Page 6/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Class Class Class Total Note:
1 (Motorcycles) 2 (Cars) 3 (Vans & Medium Trucks) 4 (Heavy Trucks & Buses) (PT4) 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 Page 7/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Class Class Class Total Note:
1 (Motorcycles) 2 (Cars) 3 (Vans & Medium Trucks) 4 (Heavy Trucks & Buses) (UR1) 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 Page 8/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Class Class Class Total Note:
1 (Motorcycles) 2 (Cars) 3 (Vans & Medium Trucks) 4 (Heavy Trucks & Buses) (URL2) 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 Page 9/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Class Class Class Total Note:
1 (Motorcycles) 2 (Cars) 3 (Vans & Medium Trucks) 4 (Heavy Trucks & Buses) (BU1) 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 Page 10/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Class Class Class Total Note:
1 (Motorcycles) 2 (Cars) 3 (Vans & Medium Trucks) 4 (Heavy Trucks & Buses) (BT2) 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 Page 11/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Class Class Class Total Note:
1 (Motorcycles) 2 (Cars) 3 (Vans & Medium Trucks) 4 (Heavy Trucks & Buses) (BT3) 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 Page 12/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Class Class Class Total Note:
1 (Motorcycles) 2 (Cars) 3 (Vans & Medium Trucks) 4 (Heavy Trucks & Buses) (BL4) 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 Page 13/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Page 14/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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 Page 15/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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. Page 16/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14
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 Page 17/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14
Faculty: Faculty of Civil and Environmental Engineering Department : Department of Infrastructure and Geomatic Engineering Title: SIGNALISED INTERSECTION CAPACITY AND LEVEL OF SERVICE 8.0 Page 18/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 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% gradien t. 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 Page 19/19 Edition : Checking no. : Effective date : Ammendment date : 2 2 7/9/14 1/9/14 (C) Average Stopped Delay per Vehicle Average delay per vehicle, d on a particular intersection arm is given by the fo rmula:
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
