Smart Traffic Signs
I can communicate!
By:
Salil S. Gokhale
Preston DeFrancis
Smart Traffic Signs
I.
Designing a Smart Traffic Sign
II.
Demonstrating a Working
Prototype
III.
Enhancing the Concept
Think
!
Designing a Smart Traffic Sign
General problem – Road signs do not
always convey information effectively
1. Inclement weather
2. Poor or infrequent placement
3. Stolen for dorm room decoration
Designing a Smart Traffic Sign
Interstate Traffic Sign Problem
Designing a Smart Traffic Sign
Solution: a “Smart” Traffic Sign
1. Transmits information over a wireless link
2. Replaces or augments traditional road signs
3. Delivers information directly inside a motor
vehicle
Designing a Smart Traffic Sign
Goal: Deliver a prototype of a Smart
Traffic Sign that
 Uses a 433.9.2 MHz radio frequency link
 Operates on power supplies available in
cars(receiver) and near interstate signs (transmitter)
 Outputs information to driver on an illuminated
LCD screen
Designing a Smart Traffic Sign
System-level architecture
Transmitter:
Flash
EEPROM
Stamp PIC
PIC on the
modules
Receiver:
LCD
display
Flash
EEPROM
Stamp PIC
PIC on the
modules
Transmitter sends data serially to the receiver
Designing a Smart Traffic Sign
Software components for Modules:
Transmitter: - Encodes information
- Contains Protocol
Receiver: - Decodes Information
- Contains protocol conversion
program
- Includes LCD driver
Designing a Smart Traffic Sign
Power Supplies:
1. Receiver: Plugs into +12V DC supply of car’s
cigarette lighter
2. Transmitter: Uses 120 V AC supply of urban
bridge structure signs
Designing a Smart Traffic Sign
Summary of Specifications:
Frequency of operation
433.92 MHz
Receiver Power Supply
12V DC
Transmitter Power Supply
120 V AC
Display
Backlit LCD
Antenna Type
Loop
Demonstrating a Working Prototype
Packaging the Modules:
Receiver: Small, user-friendly package that
attaches with Velcro to car’s
dashboard
Transmitter: Weatherproof package enclosing
power supply and module
The First Car!
The 1995 Dodge Neon was the first car to
have the Smart Traffic Sign installed in it
Demonstrating a Working Prototype
Testing the modules in heavy snow
Approximate distance of operation: 300 ft.
Demonstrating a Working Prototype
Testing the modules in clear weather
Approximate distance of operation: 310 ft
Demonstrating a Working Prototype
Conclusions for test:
1. Weather conditions do not significantly impair
performance
2. Current minimum range is enough to transmit
3072 characters at 9600 baud, more than enough
for the demonstration
Demonstrating a Prototype
Demonstrating a Prototype
Summary of Prototype:
1. Transmitter and receiver housed in appropriate
packages
2. Field tests verified the meeting of project goals
3. Demonstration validated the real-world
operation of the prototype
Enhancing the Concept
A second generation prototype will:
1.
Provide more range: increased receiver
sensitivity allows better range from same
transmitter power
2.
Decrease size of units: new, smaller
modules could make units more attractive
Enhancing the Concept
A second generation prototype will:
1. Use more sophisticated modulation:
improve resistance to noise
2. Provide antenna flexibility: Many types
of antenna could provide directional
transmission
Enhancing a Concept
Further Improvements:
1. Lane Specificity - provide lane-specific
information, perhaps using a buried
antenna
2. User interface - Determine best method
of getting information to driver
Enhancing the Concept
Work has begun on the second generation
model
Enhancing the Concept
Summary of Recommendations:
1. Build a second-generation prototype for
increased performance
2. Develop a method of providing lane
specific information
3. Research most effective user interfaces
Acknowledgements
Professor Frank Merat, Project Technical
Advisor
Professor Bob Gura, Project management
Advisor
Professor Sreenath, Course Instructor
Dr. R.L. Mullen, Civil Engineering Advisor
Brian Leech
Ted Square
Smart Traffic Signs
I can
communicate!
Demonstration!