Wireless Sensor-Based Traffic
Light Control
Malik Tubaishat, Qi Qi, Yi Shang, Hongchi Shi
Problem Statement
• Comparison of performance of wireless sensor
based networks(Single sensor and dual
sensor) with fixed traffic cycle TLC.
• Non-Occupancy Detection(NOD) and
Occupancy Detection(OD) based comparision
• Effect of sensor distance on Average waiting
time.
Results
• Used GLD(Green Light District) for their
simulation
• Implemented Fixed Light controller, Single
Sensor based and Fixed Sensor based
• Some values:
– Random Spawn Frequency : 0.1-0.35
– Cycle length 5000 averaged over 5 cycles.
(a) urban-like map
and
(b) downtown-like map
One Sensor- Urban Network
One Sensor- Downtown Network
Key take-aways
• Two Sensor Model outperforms one Sensor
Model
• Two sensor model performance is close to
best first which knows the exact number of
waiting vehicles.
• OD model, the closer the sensor to the
junction the better the performance is.
Sensor Placement in Real-Time Sensor
Based Traffic Light Control
• Infrastructure Based Controllers
• Performance based Measurements
• Control Decision through Sensor data
Outline
• Agent based Controllers
– Learn the expected waiting times of vehicles and
set the traffic lights accordingly
• Infrastructure Based Controllers
– Change the traffic flow based on the current flow
of Traffic
– They basically know the queue length and act on
this information
List of Controllers:
• Random: Switched Traffic at Random
• Most Cars: Move lanes regardless of the queue
length
• Best First: Give priority to lanes with maximum
length
• Longest Queue: Selects only the lane with
maximum length
• Relative Longest Queue: No. off road users is
divided on the basis length of the lane to get
relative rewards for traffic light settings
Control Decision Through Sensor Data
One Sensor Based Controller:
• NOD-Non-Occupancy Based Detection
• OD-Occupancy Based Detection
• Two Sensor-based Controller
• The Gain Value is the queue length for
infrastructure-based TLC.
• In every cycle the TLC adds the gain value for
the possible sign configurations and selects
the sign configuration with the maximum gain
value
Future Work
• Focus work more towards increasing the life
time of sensors
• Study performance in realtime with smaller
intervals.
Reference
• Wireless Sensor-Based Traffic Light Control, Malik Tubaishat, Qi Qi, Yi
Shang, Hongchi Shi, Consumer Communications and Networking
Conference, 2008. CCNC 2008. 5th IEEE
Thank You
-Questions...