Meet Our Team TRAFFIC SIGNAL DESIGN Teacher Teacher Ts. NOR AZIAH FATMA BINTI ABDUL AYAH @ ABDUL AZIZ Civil Egineering Department Politeknik Sultan Mizan Zainal Abidin SUHAILA AZURA BINTI ABD SALAM Civil Egineering Department Politeknik Sultan Mizan Zainal Abidin
Are you familiar with the function of the colour traffic signal? RED means STOP AMBER means READY TO STOP GREEN means GO
So the priority intersection will be replaced with signalized intersections. The objectives of traffic signal at an intersection: 1. To reduce the average delay of all vehicles and probability of crash. 2. To minimizing the possible conflicts points when assigning the right of way to different traffic streams at different times. When the volume of traffic increases, minor road vehicles had to wait longer before sufficient gap to cross or merge. Why we need traffic signals
DISADVANTAGES ADVANTAGES 1. Provide orderly movement of traffic 2. Minimize the number of conflicting movements 3. Increase capacity 4. Interrupt heavy traffic to allow other traffic to enter or cross. 5. Coordinated continuous movement of traffic at a desired speed 6. Promote driver confidence 1. Increase total intersection delay especially during of peak periods 2. Probable increase in certain types of accidents 3. Interrupt the progressive flow of traffic on a route cause delay & stop 4. When improperly located causes unnecessary delay 5. When improperly timed, causes excessive delay, increasing driver irritation
TRAFFIC SIGNAL PHASE 1) Follow the guidelines - Arahan teknik (Jalan) (2) 13/87 A Guide to the design of traffic signals. 2) It involves the physical design and the range of time of each signal phase.
RED GREEN AMBER RED CYCLE: A signal cycle is one complete rotation through all of the indications provided.
RED GREEN AMBER RED CYCLE: A signal cycle is one complete rotation through all of the indications provided. CYCLE LENGTH: The time in seconds that it takes a signal to complete one full cycle of indications t
RED GREEN INTERVAL: Indicates the change from one stage to another
3s t second 3s t second t second PHASE (N-S) PHASE (W-E) CHANGE INTERVAL : Or yellow time is provided after green time for movement. The purpose is to warn approaching driver during the end of a green time about the coming of a red signal.
3s t second 3s t second t second PHASE (N-S) PHASE (W-E) CLEARANCE INTERVAL; A period during which all signal faces show red (for clearing off the vehicles in the intersection.
3s t second 3s t second t second t second PHASE (N-S) PHASE (W-E) GREEN INTERVAL: Green indication for a particular movement. Also the actual duration the green light of a traffic signal is turned on.
LOST TIME: Time during which the intersection is not effectively utilized for any movement. i.e. : When the signal turns from red to green, the vehicle in the front of the queue, will take some time to perceive the signal (reaction time) and some time will be lost here before he moves.
3s t second 3s t second t second t second PHASE (N-S) PHASE (W-E) PHASE: The green interval plus the change and clearance intervals that follow it. Thus, during green interval, non conflicting movements are assigned into each phase. It allows a set of movements to flow and safely halt the flow before the phase of another set of movements start.
2 PHASE CYCLE N N S S W E W E 7/4/2023 PKK/JKA/CC503/CHAPTER 3 14 Phase 1 Phase 2
3 PHASE CYCLE Option 1 (Major Lane W-E) N S W E N S W E N S W E 7/4/2023 PKK/JKA/CC503/CHAPTER 3 15 Phase 1 Phase 2 Phase 3
3 PHASE CYCLE Option 2 (Major Lane W-E) N S W E N S W E N S W E 7/4/2023 PKK/JKA/CC503/CHAPTER 3 16 Phase 1 Phase 2 Phase 3
3 PHASE CYCLE Option 3 (Major Lane N-S) N S W E N S W E N S W E 7/4/2023 PKK/JKA/CC503/CHAPTER 3 17 Phase 1 Phase 2 Phase 3
3 PHASE CYCLE Option 4 (Major Lane N-S) N S W E N S W E N S W E 7/4/2023 PKK/JKA/CC503/CHAPTER 3 18 Phase 1 Phase 2 Phase 3
4 PHASE CYCLE IT’S YOUR TURN TO THINK 4 Hint : There are at least three possible phasing options for 4 phase cycle.
4 PHASE CYCLE Option 1 N S W E N S W E N S W E N S W E Phase 1 Phase 2 Phase 3 Phase 4
4 PHASE CYCLE Option 2 N S W E N S W E N S W E N S W E Phase 1 Phase 2 Phase 3 Phase 4
4 PHASE CYCLE Option 3 (Major Lane W-E) N S W E N S W E N S W E N S W E Phase 1 Phase 2 Phase 3 Phase 4
4 PHASE CYCLE Option 4 (Major Lane N-S) N S W E N S W E N S W E N S W E Phase 1 Phase 2 Phase 3 Phase 4