traffic light setting
DESCRIPTION
TRANSCRIPT
KKKA 6424 INTELLIGENT URBAN TRAFFIC CONTROL
SYSTEM
Prof. Dr. Riza Atiq Abdullah O.K. Rahmat
ASSIGNMENT (1)PREPARED BY :
1 -HAIDER FARHAN P65405 2 -MUSTAFA TALIB P60915 3 --SAHAR ABD ALI P65295
Introduction Traffic lights
Traffic lights, also known as traffic signals, traffic lamps, signal lights, robots and semaphores. Are signaling devices positioned at or near road intersections, pedestrian crossings and other locations to control competing flows of traffic. Traffic lights were first installed in 1868 in London, United, now used in almost every city of the world. Traffic lights alternate the right of way accorded to road users by displaying lights of a standard color (red, yellow/amber, and green) following a universal color code (and a precise sequence to enable comprehension by those who are color blind).
In the typical sequence of color phases:
Illumination of the green light allows traffic to proceed in the direction denoted, if it is safe to do so
Illumination of the yellow/amber light denoting prepare to stop short of the intersection, if it is safe to do so
Illumination of the red signal prohibits any traffic from proceeding
Usually, the red light contains some orange in its hue, and the green light contains some blue, said to be for the benefit of people with red-green color blindness
Single aspects The simplest traffic light comprises either a single or a pair of colored aspects that warns any user of the shared right of way of a possible conflict or danger. Flashing Red: Treat as a stop sign. Also can signal the road is closed. Flashing Yellow: Caution, crossing or road hazard ahead Flashing Green: Varies among jurisdiction; can give permission to go straight as well as make a left turn in front of opposing traffic (which is held by a steady red light), or
can indicate the end of a green cycle before the light changes to a solid yellow
Case study
Our team which consists of three engineers selected a series of intersection of three, these three intersections are located on the road which link between Bangi (UKM), Kajang, Sepakat, and the highway lead to KL as shown in the figure below.
Each one of these intersections are consist of three legs (three phases) and all phases have two lanes in each intersection.
As a work team after selecting these intersections we conducted the traffic count survey for one hour for each intersection, and we found that the cycle time of traffic light for each intersection is (120 seconds),(160 sec ),and (180 sec ) ,respectively, and the all red for each approach ( 2 seconds ), and amber for each approach ( 3 seconds ).
Intersection-1-
This is the first intersection linking Kajang, Babgi, and (UKM) as shown in the figure below.
DATA OF INTERSECTION: 1
Traffic Flows in 15 Min
KAJANG
Phase -1-
UKM
Phase -2-
BANGI
Phase -3-
Cars/Van 755 846 361
Lori < 5 ton 42 118 37Lori > 5 ton 13 4 5Motorcycle 322 215 137Bus 10 14 5Mini Bus 12 17 10
Passenger Car Unit Data traffic for one hour
so we need the table below
Bil Vehicle Passenger Car Unit
1 Car / van / jeep / mpv 12 Lorry < 5 ton 1.753 Lorry > 5 ton 2.25
4 Trailer 35 Mini Bus 2.56 Bus 2.757 Motorcycle 0.35
Phase
Traffic Flows in 1 hour Total
Car Lorry<5ton
Lorry>5ton
Trailer
Mini Bus
Bus M/cycle (pcu/hr)
1 755 42 13 0 12 10 322 1027
2 846 118 4 0 17 14 215 1216
3 361 37 5 0 10 5 137 524
PCU UNIT
1 1.75 2.25 3 2.5 2.75 0.35
Phase
Number of Lanes
Saturation Flow
per Lane (pcu/hr)
Saturation Flow
(pcu/hr)
Actual Flows
(pcu/hr)
Flow / Saturatio
n Flow Ration
Green Time Split
1 2 1800 3600 1027 0.33 0.44
2 2 1800 3600 1216 0.28 0.37
3 2 1800 3600 524 0.14 0.18
Total = 0.75 =Y
L= 3 *(2+3) = 15 sec
Cycle time (C0 ) = 1.5 L + 5 / 1- Y = 1.5*(15)+5 / 1-0.75=110 sec
Effective green time = 110 – 15 = 95 sec
Phase -1- green time =95* 0.44 =41.8 = 42 sec
Phase-2- green time =95*0.37 = 35.15 = 36 sec
Phase-3- green time =95*0.18 = 17.1 = 18 sec
Total of green time = 42+36+18 = 96 sec
Total of amber & all red time =3 * (2+3) = 15 sec
Cycle time = 96 + 15 = 111 sec
Intersection-2-
The second intersection links Kajang, UKM, and Sepakat as shown in the figure below.
DATA OF INTERSECTION: 2
Traffic Flows in 15 Min
KAJANG
Phase-1-
Ukm
Phase-2-
SEPAKAT
Phase-3-
Cars/Van 808 918 338
Lori < 5 ton 46 135 46
Lori > 5 ton 17 5 11
Motorcycle 351 238 117
Bus 11 14 1
Mini Bus 14 20 4
Bil Vehicle Passenger Car Unit
1 Car / van / jeep / mpv 1
2 Lorry < 5 ton 1.75
3 Lorry > 5 ton 2.25
4 Trailer 3
5 Mini Bus 2.5
6 Bus 2.75
7 Motorcycle 0.35
Phase
Traffic Flows in 1 hour Total
Car Lorry<5ton
Lorry>5ton
Trailer Mini Bus
Bus M/cycle (pcu/hr)
1 808 46 17 0 14 11 351 1115
2 918 135 5 0 20 14 238 1336
3 338 46 11 0 4 1 117 498
PCU UNIT
1 1.75 2.25 3 2.5 2.75 0.35
Phase
Number of Lanes
Saturation Flow per
Lane (pcu/hr)
Saturation Flow
(pcu/hr)
Actual Flows
(pcu/hr)
Flow / Saturation
Flow Ration
Green Time Split
1 2 1800 3600 1115 0.31 0.37
2 2 1800 3600 1336 0.37 0.45
3 2 1800 3600 498 0.14 0.17
Total= 0.82=Y
L = 3 * (2+3) = 15 sec
Cycle time (C0)=1.5L+5 /1-Y=1.5*15+5/1-0.82=155 sec
Effective green time = 155- 15 = 140 sec
Phase-1- green time =140* 0.37 =51.8 =52 sec
Phase-2- green time=140 *0.45 = 63 sec
Phase-3-green time=140 *0.17=23.8 = 24 sec
Total of green time = 52+63+24 = 139 sec
Total of amber & all red = 3*(2+3) =15 sec
Cycle time = 139 +15 = 154 sec
Intersection-3-
This is the third intersection which links Kajang, UKM, and the highway as shown in the figure below.
DATA OF INTERSECTION: 3
Traffic Flows in 15 Min
KAJANG
Phase-1-
Ukm
Phase-2-
HIGHWAY
Phase-3 -
Cars/Van 768 956 585
Lori < 5 ton 42 137 24
Lori > 5 ton 11 5 9
Motorcycle 333 258 34
Bus 11 14 3
Mini Bus 14 22 0
Bil Vehicle Passenger Car Unit
1 Car / van / jeep / mpv 1
2 Lorry < 5 ton 1.75
3 Lorry > 5 ton 2.25
4 Trailer 3
5 Mini Bus 2.5
6 Bus 2.75
7 Motorcycle 0.35
Phase
Traffic Flows in 1 hour Total
Car Lorry<5ton
Lorry>5ton
Trailer Mini Bus
Bus M/cycle (pcu/hr)
1 768 42 11 0 16 12 333 1056
2 940 134 4 0 22 14 205 1348
3 585 24 9 0 0 3 34 667
PCU UNIT
1 1.75 2.25 3 2.5 2.75 0.35
Phase Number of Lanes
Saturation Flow per
Lane (pcu/hr)
Saturation Flow (pcu/hr)
Actual Flows
(pcu/hr)
Flow / Saturation Flow Ration
Green Time Split
1 2 1800 3600 1056 0.29 0.34
2 2 1800 3600 1348 0.37 0.44
3 2 1800 3600 667 0.18 0.21
Total= 0.84 = Y
L = 3 * (2+3) = 15 sec
Cycle time (C0) = 1.5L+5/1-Y=1.5*15+5/1-0.84= 175
Effective green time =175 – 15 = 160 sec
Phase-1- green time = 160 * 0.34=54.4 = 55 sec
Phase-2- green time = 160 * 0.44 =70.4 = 71 sec
Phase-3- green time = 160 * 0.21 =33.6 = 34 sec
Total time green = 55 + 71 + 34 = 160 sec
Total of amber& all red =3 *(2+3) =15 sec
Cycle time = 160 + 15 = 175 sec
Summary of results for cycle time ( C₀ ) and effective green time ( Ge)
Intersection
Cycle time C₀ (sec )
Effective Green time Ge(sec )
1 111 65
2 154 140
3 175 160
Calculation of cycle time :After calculation of cycle time with Webster method, the highest cycle time was for intersection 3 and it was equal to175 seconds. So adjust all intersection using Cycle Time 175 seconds.
Intersection 1 :Cycle time = 175 sec Total of amber and all red time = (3+2) x3=15 sec Total green time = 175-15=160sec Phase 1 green time = 160* 0.44=70.4sec =71 sec Phase 2 green time =160 *0.37=59.2sec=60sec Phase 3 green time = 160*0.18=28.8sec=29sec
Green time (sec )
Phase
71 1
60 2
29 3
160 Total
Intersection 2: Cycle time = 175 sec Total of amber and all red time = (3+2) x3= 15sec Total green time = 175-15 =160sec Phase 1 green time =160*0.37=59.2sec=60sec Phase 2 green time =160*0.45= 72sec Phase 3 green time = 160*0.17=27.2sec =28sec
Green time (sec ) Phase
60 1
72 2
28 3
160 Total
Intersection 3:
Cycle time =175 sec Total of amber and all red time = (3+2) x3=15 sec Total green time = 175-15= 160 sec Phase 1 green time = 55sec Phase 2 green time = 71sec Phase 3 green time = 34 sec
Green time (sec ) Phase
55 1
71 2
34 3
160 Total
Calculation of offset time :
Offset time : L/S - ( Qh+ loss) Where Q = Number of vehicles queued per lane, vehicle. h = Discharge Headway of queued vehicle in seconds/vehicle. Typical value of h is 2 seconds / vehicle. S = Average Speed in meter in second L = Distance between intersections in meter Loss1 = Loss Time associated with vehicles starting from rest at the first downstream signal (2 seconds can be used as a default).
-1-offset1S= 10 m/sL1= 1600 mQ1= 12 vehh=2 sec per vehloss =2 secOffset1 =1600/10-(12x2+2) =134secphase Green time 1 55 2 71 3 34 total 160RELATIVE OFFSET= 134 , ABSOLUTE OFFSET=134
2-offset2 S= 10 m/s L2= 250m Q2= 14veh h=2 sec per veh loss =2 sec Offset 2 =250/10-(14x2+2) =-5sec RELATIVE OFFSET =-5, ABSOLUTE OFFSET =129
3-Offset3= 0
Thank you for your kind
attention