INTRODUCTION TO SIGNAL TIMING & TRAFFIC CONTROL 1
WHO ARE WE? 2
WHAT ARE WE GOING TO DO TODAY? Learn about transportation engineering and careers offered. Introduce essential concepts about signal timing. LIVE! Queuing Demonstration. Have fun!
HOW DO YOU GET TO SCHOOL? 4
WHAT IS TRANSPORTATION ENGINEERING? 5
VIDEO A Abridged History of Transportation 1:44 6
Careers for Transportation Engineers Design freeways, streets, highways, sidewalks, bike lanes. Plan and manage transit systems like rail or subways Manage and control traffic signals Design Intelligent Transportation Systems (ITS) Plan, manage, and operate self-driving cars Plan, manage, and operate inclusive transportation systems- kids, elderly, working adults, handicapped, etc. Predict the FUTURE! 7
INTRODUCTION TO SIGNAL TIMING & TRAFFIC CONTROL 8
Traffic Control Terms Phase red, green, or yellow light indication Cycle the completion of both a red and green phase. 9
TWO PHASES CYCLE 10
Traffic Control Terms Delay the amount of time a vehicle is stopped at a red light. Queue a line of vehicles waiting at a red light. 11
WHAT IS A QUEUE? 12
Traffic Control Terms Timing Plan Efficiency the amount of time, usually seconds, that is dedicated to each phase the ability of the traffic signal timing plan to reduce delay and minimize the queue. 13
Which intersection is better? Gridlock - A situation of very severe traffic congestion. 14 Source: https://en.oxforddictionaries.com/definition/gridlock
TRAFFIC SIMULATION Did you know that Transportation Engineers use simulation to develop more efficient signal timing patterns? 15
ACTIVITY 1: TRANSIT TROUBLE! Let s see how good you are at controlling traffic! 16
INSTRUCTIONS! 17 Transit Trouble configuration: Click on Play! Welcome Screen: Click on Arcade Mode and then Level 1
INSTRUCTIONS! Welcome Dialog Click on Next Simulator Display: 18
Frustration Meter: Timer! Every level lasts for 60 seconds Traffic Light! Click on the traffic light at an intersection to change it. Get Help! Click on it NOW 19
Who is the First Group to get to Level 4?? There is a prize!! 20
anual Traffic Control Fixed Traffic Control What is after Level 4? Manual traffic control (Level 1-4) That s the same as what the police do to control a signal after a Razorback baseball game However, this is not very efficient would you like to sit at a traffic signal all day??? Fixed Time Control (Level 4+) Signal phase times are pre-set based on historic traffic patterns Fixed time control can be more efficient 21 if set correctly.
FIXED TIME CONTROL: LEVEL 5! Intersection Selected Time in seconds for phase 22
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LIVE QUEUE SIMULATION! 25
Preparing for our Experiment 1. Assign roles 2. Observe queues and phases 3. Draw conclusions from our data. 26
Assignment of Roles 1 1 2 Everyone Else Traffic Controller Police Officer Traffic Monitor Vehicles 27 Open the envelopes and reveal your assignment.
Approach C Approach A Approach D TC Approach B 28
Traffic Controller Control traffic using the signal. 1. Press the phase change button on the top of the traffic signal. 2. Try to minimize the queues. 29
Police Officer Make sure no one is speeding 1. Watch the cars and trucks. 2. Stop vehicles that are speeding. 30
Traffic Monitor Observe behaviors and cycle efficiency Write down the observations on the data collection handout. 31
Cars Single drivers, pass through the intersection and obey the signals 1. Go to your assigned approach. 2. Follow the pattern listed in your envelope. A B D C 3. Obey the traffic signals and speed limit. 32
Trucks Pairs of two, stay together through the intersection and obey the signals 1. Find your partner. 2. Go to your assigned approach. 3. Follow the pattern listed in your envelope. A D C B 4. Obey the traffic signals and speed limit. 33
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DISCUSSION FOR ROLE PLAY Observers please report to the group about your observation. Were any long queues formed? Did delay cause frustration? Were there differences between behaviors of trucks and cars? 35
FIXED TIME SIGNAL CONTROL ANALYSIS Now we will analyze fixed time control. Previous simulations have produced the data on the handouts. You are going to calculate cycle lengths and delay and see what you find! Instructions: Count off by four to make small groups. Answer the questions on the flipcharts. We will come together to talk about our findings. 36
Fixed Time Control Calculate Cycle Length and Delay for each Approach Data from Approach A (example) CYCLE NUMBER Length of Queue Length of Red Phase (sec) Length of Green Phase (sec) Cycle Length (sec): TOTAL DELAY Time (sec) 1 3 6 6 6 + 6 = 12 3x6= 18 2 2 3 5 3 5 3 4 4 2 8 9 5 5 5 7 Average Cycle Length: Average Delay: 1) Combine the data from the Phase Monitors and Queue Counters in the table. 2) Calculate the average DELAY and average CYCLE LENGTH. 37
Y- Axis Queue Statistics From this graph we can interpret the relation between the length of a cycle and the delay that occurs to a certain cycle length. X- Axis 38
Discussion Questions 1. Compare fixed and manual signal timing. Which method seemed more efficient. 2. Under what circumstances do you think fixed or manual timing would be more efficient? 3. Why is it important to consider both trucks and cars when designing signal timing schemes? 4. What are the challenges of designing signal timing schemes when there is more than one connected intersection? 39
Everyone! 40
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