KATHMANDU UNIVERSITY
SCHOOL OF ENGINEERING
DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING
PROJECT REPORT
4-WAY TRAFFIC LIGHT SYSTEM
A First year project report submitted in partial fulfilment
of the requirements for the degree of
Bachelor of Engineering
By:
Nirajan Diyali (12060)
Bibek Baraili (12027)
Subrat Kumar Karna (12032)
Senish Khadka (12035)
Sanjay Rizal (12047)
December 2022
CERTIFICATION
FIRST YEAR PROJECT REPORT
ON
4-WAY TRAFFIC LIGHT SYSTEM
By:
Nirajan Diyali (12060)
Bibek Baraili (12027)
Subrat Kumar Karna (12032)
Senish Khadka (12035)
Sanjay Rizal (12047)
Approved by:
1. Project Supervisor
___________________
(Signature)
____________________________
(Name)
_______
(Date)
____________________________
(Name)
_______
(Date)
2. Head of the Department
___________________
(Signature)
ABSTRACT
A Four Way Traffic Light Controller is an electronic device that creates a four way traffic
light system through the concept of digital logic design. In this project we have used basic
electronic principles to build a simple Four Way Traffic Light Controller using 555 timer
IC which is an important part of this project as from this timer we set the time of each traffic
light to glow on different intervals of time.
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ACKNOWLEDGMENT
We would like to express our sincere gratitude to the Department of Electrical and
Electronics Engineering for providing us with the opportunity to be a part of the project
entitled “ 4 Traffic Light Controller”. Our special thanks to our supervisor Pramish
Shrestha Sir for his continuous guidance and support provided to us throughout this project
work. We are grateful to our coordinator and all the teachers. Likewise, we would like to
thank Dr. Ram Kaji Budhathoki, Head of the Department, and the lab assistants. Last but
not the least, we would also like to thank all the faculty members, seniors and friends who
helped us directly or indirectly to complete our project.
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SYMBOLS AND ABBREVIATIONS
A. Symbols

Ω = Ohm

μF= Micro Farad
B. Abbreviations

IC=Integrated circuit

LED=Light Emitting Diode

VCC=Voltage Common Collector

CD= CMOS Decade Counter
List of Figures
Figure 1: CD4017 IC ........................................................................................................... 7
Figure 2: NE555 Timer ........................................................................................................ 8
Figure 3: Capacitors ............................................................................................................. 9
Figure 4: Resistor ............................................................................................................... 10
Figure 5: LEDs ................................................................................................................... 10
Figure 6: Circuit Diagram .................................................................................................. 17
Figure 7: PCB Circuit ........................................................................................................ 18
Figure 8: CD4017 Data sheet[4] ........................................................................................ 20
Figure 9: NE555 Timer IC Data Sheet[5] .......................................................................... 21
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TABLE OF CONTENTS
ABSTRACT ....................................................................................................................... iii
ACKNOWLEDGMENT..................................................................................................... iv
SYMBOLS AND ABBREVIATIONS ................................................................................ v
List of Figures ...................................................................................................................... v
TABLE OF CONTENTS .................................................................................................... vi
CHAPTER I : INTRODUCTION ........................................................................................ 1
1.1 Background ........................................................................................................... 1
1.2 Motivation ............................................................................................................. 1
1.3 Problem Description .............................................................................................. 2
1.4
Objectives .............................................................................................................. 2
1.5
1.6
1.7
Methodology ....................................................... Error! Bookmark not defined.
Limitations ............................................................................................................ 2
Organisation of Report .......................................................................................... 2
1.8 Summary ............................................................................................................... 3
CHAPTER II: TECHNOLOGY AND LITERATURE SURVEY ...................................... 4
2.1 Literature Survey ................................................................................................... 4
2.2 Components required ............................................................................................ 7
CHAPTER III: METHODOLOGY ................................................................................... 11
3.1 System overview ................................................................................................. 11
3.2 System flow ......................................................................................................... 11
CHAPTER IV: SYSTEM ANALYSIS ............................................................................. 13
4.1 Circuit Analysis ................................................................................................... 13
4.2 Problems Encountered......................................................................................... 13
CHAPTER V: CONCLUSION AND FUTURE WORK .................................................. 14
REFERENCES .................................................................................................................. 16
A. APPENDIX ................................................................................................................ 17
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CHAPTER I : INTRODUCTION
1.1 Background
Traffic Light System is a very essential part when it comes to the matter of management of
traffic. Not only being bound to vehicles but it also helps the pedestrians while crossing the
road keeping them safe. It also reduces human effort as it is used as an alternative to the
traffic police. We can consider traffic light systems a great achievement in the field of
science and technology.
This project emphasizes on the progress whilst making a four way traffic controller with
the use of 555 timer IC and CD 4017 IC. This is a simple engineering project developed to
gain knowledge about the electronic components and learning to work together as a team.
This project includes the use of 555 timer IC, 4017 IC, capacitors, LED (red, yellow and
green).
1.2 Motivation
Technology has been a blessing for human beings as it has given us a new outlook of life,
the things which seemed impossible a few years back are quite normal now. Four way
traffic light controller though a simple electronic device has great applications. It has
helped the traffic police to easily manage the traffic without being directly involved on the
roads. It has also prevented many accidents and unnecessary traffic. This project gives us a
clear understanding of the four way traffic light system and immensely benefited both
students and the user. It also provides a distinct understanding of various electrical
components.
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1.3 Problem Description
The improper management of the traffic can cause many problems in the traffic as it causes
unnecessary traffic jams and accidents, the waste of time due to the improper management
of the vehicles running around the junction of the road, difficulties for the pedestrians while
walking on the road. As four way traffic controllers usually seen are a bit expensive, we
have designed this circuit which causes very low cost and that is easily affordable. This
report and project is made in such a way that even a normal person can understand its
drawbacks and can easily understand the use of the four way traffic light system.
1.4 Objectives

To design and develop a simple model of a four way traffic light controller.
1.5 Limitations

Works only for a fixed time interval.

Needs regular maintenance.

Are subject to vandalism.

Traffic density is not recognized by this system and it may cause heavy traffic on
one side of the road while the other roads are free.
1.6 Organisation of Report
The report has been divided into five different chapters where Chapter 1 provides the brief
description of the project. This chapter includes basic introduction, the factors considered
as motivation, problems to be addressed after completion of the project, main objective of
the project with some limitations of the project & surface methodology. Similarly, Chapter
2 includes the technology & literature survey which includes the description of every
component required in this project. Chapter 3 includes the experimental setup &
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methodology of this project in brief which provides detailed information of our project
including the circuit diagram. Likewise, Chapter 4 includes the case study carried out i.e., it
includes the quantitative analysis of our working model along with its output in various
conditions. Lastly, Chapter 5 includes the conclusion & future scope of our project. It also
involves some problems encountered till date.
1.7 Summary
This device is used to control a four way traffic system. It is useful in controlling the traffic
without the direct need of the traffic police and also prevents many accidents on the road.
We have used two main components for this project. They are: 555 timer IC and CD 4017
IC. Through the use of this 555 timer IC we set up the time for the circuit i.e the traffic light
device according to our use.
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CHAPTER II: TECHNOLOGY AND LITERATURE SURVEY
2.1 Literature Survey
Traffic signals are vital for traffic management. It is essential to increase the efficiency of
the traffic controller to alleviate traffic congestion.The basic idea is that the project we have
chosen is a traffic light controller is to create a 4 way traffic controller through the concept
of digital logic design. Idea behind the design is to avoid accidents of vehicles by providing
appropriate signals to different directions for a limited time slot, thus providing safety
against collisions of vehicles. After which the next waiting drivers will be given the same
treatment.
2.1.1 History
The evolution of traffic light can be traced back to 200 years, but before becoming a
reliable system we know today it has recovered from a number of design flaws and
revolutionary dead-ends and as well as all out explosions.
In 1920, a Detroit policeman, William Potts invented the first three colour lights. His four
way signal head used signal lamps and was designed to be suspended over the centre of a
junction to control the traffic light from four approaches. It was the first signal to resemble
the operation we know today.
During the 1930’s, experiments were carried out in the use of vehicle actuation to make the
traffic signals responsive to vehicles using a junction. An early attempt used a microphone
placed at the side of the road which would make the traffic light responsive to the horns of
the vehicles but it was not used as it disturbed the people living nearby due to the noise of
the horns.
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2.1.1 Literature Survey Continued
Sandeep Mehan in his paper “Introduction of Traffic Light Controller with Fuzzy Control
System '' proposes a system where he prepares a Design For Fuzzy Logic Traffic Light
Controller. The real time parameters such as traffic density and queue length are obtained
by using image processing techniques. So the on and off timings for the green, red and
yellow lights are adjusted as per the actual road conditions. Fuzzy logic has been widely
used to develop a traffic signal controller because it allows qualitative modelling of
complex systems. Therefore, his paper discusses the traffic control strategy, which dictates
the design criteria for the fuzzy logic controller. The components of the fuzzy logic
controller-the fuzzies, the fuzzy rule base formulated by human experts, the fuzzy inference
engine and the defuzzifier. [1]
Furthermore, Faizan Mansuri and Viraj Panchal in their paper “Four-Way Traffic Light
Controller Designing with VHDL(very high-speed integrated circuit) '' includes the intense
use of programming and machine learning algorithms for their design. It requires them to
develop a state machine based controller for traffic signals at a four way intersection. This
intersection has two travel lanes in each direction; east, west, north and south. In addition,
each direction has a dedicated left turn lane. Each street i.e. NS (North-South) and EW
(East-West) have a sensor to indicate the presence of cars at the intersection or if cars are
approaching the intersection. This project stresses the difference of writing VHDL for
modelling and synthesis and that VHDL should not be thought of as a programming
language. Hence focusing on VHDL, they give proper design of combinational and
sequential circuits. It requires proper definition of pin constraints for interfacing
peripherals external. [2]
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Similarly, a different approach was taken by T.E Somefun, C.O.A. Awosope, A.
Abdulkareem, E. Okpon, A.S. Alayande, and C.T. Somefun in their paper “Design and
Implementation of Density-Based Traffic Management System”. In their paper, they use
infrared sensors as counters to measure the traffic density in each lane. The infrared sensors
are also for speed detection with a Bluetooth module and Bluetooth serial monitor. These
sensors are interfaced with the traffic light through a microcontroller. The microcontroller
which was used to implement this is the Arduino Mega with the Atmega 2560 chip. The
system was developed to alleviate traffic congestion and over-speeding offenders using a
case study of an intersection in Uyo, Akwa Ibom State, Nigeria which usually has severe
traffic congestion. Their system was tested and all objectives were accomplished. Results
obtained from the implementation of the prototype design showed that traffic control and
speed detection using infrared sensors and Arduino Atmega 2560 give a better performance
and the time taken to clear traffic at an intersection reduced significantly with 60% time
saved. [3]
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2.2 Components required
We have two main components. The first one is a 555 timer IC and another one is a
CD4017 IC. There are also other basic components which we have used in our circuit as
described as follows
2.2.1 CD4017 IC
This IC is commonly known as the 4017 decade counter or 5 –stage Johnson counter. It’s
called 5 stage Johnson counter because it has five D flip flops which control the outputs on
this IC. It has 16 pins in which pin eight and 16 are Vin and Ground, respectively. There are
10 outputs form Q0- Q9 which are distributed from pin 1-11. These pins go from low to
high one by one on each clock cycle which is provided on pin 14.
Pin 15 represents the master reset while pin 13 represents Enable. The 12th pin gives a
complemented Q5-9 output. Now the reset and enable pin will be grounded to show the
inputs are low. When the reset is turned high the Q0 out but will become high irrespective
of which output was high. If high input is given on the enable pin that will pause output on
whichever pin it is high on. This clock is a low to high edge trigger, which means that
whenever high is given on pin 14 the output will change and shift to the next output pin.
Figure 1: CD4017 IC
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2.2.2 NE555 Timer IC
This IC is well known for timing the devices according to the desired need of the circuit.
The timer IC has a SR flip flop, resisters, transistor and comparators. The IC is known as
555 timer because it contains three 5 kilo ohms resistors in series. The main function of this
IC in our circuit is to provide us with a high and low clock, which is why the 555 timer IC is
working in astable mode (means that output at pin 3 is not stable).
Basically, it is creating a plus which is required for the decade IC ahead in the circuit. On
pin 2 there is a trigger which activates a transistor due to which the capacitor at pin 6 starts
to be discharged through a resistor between pin 6 and 7. The discharging time depends on
R*C due to which the interval of high and low is also decided. Pin 4 and pin 8 will be
shorted with the voltage supply. Control voltage will be untouched as it has no use in these
circuits.
Figure 2: NE555 Timer
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2.2.3 Capacitors
It is a storage element which stores charge and the voltage it holds is the same as the
supplied voltage. Here, in the circuit the 100μF capacitors are connected with Pin 2 and Pin
8 of the NE55 Timer IC having common ground.
Figure 3: Capacitors
2.2.4 Resistors
It is a device which supplies resistance to the current so that the circuit is safe from
degeneration due to high voltage. In our circuit we have used resistors ranging from 220Ω
to 10kΩ. The 10 kΩ resistor and 1kΩ resistor is connected in series with Pin 6 of the IC.
The 220Ω resistor is connected with Pin 3 of NE55 Timer and with Pin 14 of CD4017 IC.
The 500Ω resistor is connected with the LEDs in the circuit.
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Figure 4: Resistor
2.2.5 LED
A light emitting diode (LED) is a semiconductor light source that emits light when
current flows through it. Electrons in the semiconductor recombine with electron holes,
releasing electrons in the form of photons. The color of light is determined by the
energy required for electrons to cross the band gap of the semiconductor. LEDs have
many advantages over incandescent light sources, including lower power consumption,
longer lifetime, improved physical robustness, smaller size, and faster switching. In this
project we have used 5-volt LEDs of different colors.
Figure 5: LEDs
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CHAPTER III: METHODOLOGY
3.1 System overview
This circuit consists of NE555 Timer IC which works on astable mode with frequecy
dependent on values of resistance and capacitance and the output is observed to be the
square wave which is then fed to the Clock pin (PIN 14) of CD4017 which works as decade
timer. The output of decade counter IC is connected to the diodes in parallel which then is
connected to the LEDs which make Red and Green LEDs work with time period of
equivalent to 6 seconds and yellow LED with time period of 2 seconds.
3.2 System flow
1) When constant DC supply of 9V-25V is supplied between the shorted point of PIN
4(Reset) and PIN 8(VCC), the NE555 timer becomes functioning.
2) The charging an discharging cycle of Capacitor shorted between PIN 2 with PIN 6
and connected to Ground produces astable output.
3) PIN 3 of NE555 Timer IC gives the astable output to CD4017 IC. The output is
connected to PIN 14 and PIN 13 and PIN 15 is grounded which enables the clock of
CD4017.
4)
The output from PIN 1,2,3,4,5,6,7,9,10,11 of CD4017 is fed to diodes connected in
parallel which then lights up for different time intervals.
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.
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CHAPTER IV: SYSTEM ANALYSIS
4.1 Circuit Analysis
The 4 way traffic circuit consists mainly of these components: CD4017 IC, NE555 Timer
IC and different coloured LEDs. The four-way traffic light circuit consists of two stages.
The first one is the timing and counting stages. The other one is an indication of the light
stage. The indication of the light stage should be properly placed on four lanes. The values
of the capacitor and the resistor set the timing of the 555 IC. It then delivers them at the
output pin. These pulses decide the timing interval of traffic light signals. The decade
counter IC has ten outputs. Q0 to Q3 will drive a green signal for the north and south lanes,
and a red signal for the east and west lanes. The output Q4 drives a yellow signal for the
north and south lanes. Then the output from Q5 to Q8 will drive a green signal for the east
and west lanes, Red signal for the north and south lanes. An output Q9 drives a yellow
signal for an east and west lane.
4.2 Problems Encountered
When 9V DC supply was given to the circuit, the power on the total load of 12 LEDs were
not enough to light up all the LEDs with higher intensity. As the capacitance and resistance
are not variable in our circuit, it works with a constant frequency which determines the time
period of each LED. Since, the ICs work on low voltage, any high voltage passing through
the IC might damage the circuit.
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CHAPTER V: CONCLUSION AND FUTURE WORK
As we are trying to make a four way traffic controller which can help control the irregular
flow of traffic in urban areas and it helps us to have a unique and systematic way of road
traffic. However, we can’t achieve our complete objectives due to complexities in ICs
which can only drive low voltages. Likewise, we have prepared our circuit in PCB which
can help to control traffic in four lanes. The core use of CD4017 and NE555 timer in
“astable” mode with the use of capacitor helps the circuit to be stable and different colours
of lights(red, yellow, green) are shown. This project uses a simple procedure for the four
way traffic light system so we can even use it in different cities of our country too.
The future work that can be carried out to modify this project are:
1) Extension of the system that works on 4 lanes to 8 lanes.
2) Detection of the traffic density on each road and making the system work accordingly.
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GANTT CHART
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References
[1] Mehan & Sharma - Proceedings of the International Conference on Advances in
Computing and Artificial Intelligence - ACAI '11, 2011.
[2] Mansuri, Faizan, and Viraj Panchal. "Four-Way Traffic Light Controller Designing with
VHDL." Department of Electronics and Communication, Institute of Technology, Nirma
University Ahmedabad, Gujarat, India, 2016.
[3] T. E. Somefun, C. O. A. Awosope, A. Abdulkareem, E. Okpon, A. S. Alayande, and C.
T. Somefun, “Design and implementation of density-based Traffic Management System,”
International Journal of Engineering Research and Technology, vol. 13, no. 9, p. 2157,
2020.
[4]https://www.ti.com/lit/ds/symlink/cd4017b.pdf?ts=1670808028506&ref_url=https%253
A%252F%252Fwww.google.com.hk%252F
[5] https://www.ti.com/lit/ds/symlink/ne555.pdf
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A. APPENDIX
Figure 6: Circuit Diagram
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Figure 7: PCB Circuit
Figure 8: Bread board testing
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Figur 9: PCB Assembly
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Figure 10: CD4017 Data sheet[4]
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Figure 11: NE555 Timer IC Data Sheet[5]
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