What are the Traffic Light Colors and their Meaning?

Traffic lights balance and command the traffic flow. They also help to reduce the number of road accidents. 

The traffic lights have mainly 3 colors named 

1) Red for "Stop"

2) Yellow for "Caution" 

3) Green for "Go". 

It can be further classified as steady lights, flashing lights, solid arrows, flashing arrows. We will be discussing all these in this article.                           

Flashing lights indicate caution, and arrows guide specific turns. 

However, at crossings that have both a traffic light signal and a traffic officer, you must go after the order of the traffic officer.  

Invention of the Traffic Light:

The first ever electric traffic light was invented in 1912.

The traffic light was invented to control the flow of traffic on the roads. It has transformed the way in which we cross the roads, helping us to be safe.               

History of the Traffic Light:

Earlier traffic lights were used to give signals to railways. 

They use the two lights. Red for "stop" and green for "go". 

The red color was chosen for "stop" as it is visible from a distance due to its long wavelength. 

Then traffic lights used gas to light up. But it had there disadvantages of gas leakages that caused safety concerns and explosions. 

When were the first traffic lights used in the USA?

As with the invention of new automobiles, cars became common. So proper traffic control was needed. 

The first ever electric traffic lights that appeared in the USA was around 1920.

Traffic Light Pattern:

Traffic lights all over the world follow the same pattern (sequence). It is listed below:




Red, Yellow, Green light with their meanings

Traffic lights Meaning of Colors:        :

Traffic light colors play an important role in communicating essential information to drivers and pedestrians. 

Each color carries a distinct meaning which guides actions and decisions on the road.

1) Red Traffic Light Meaning:

The red traffic light can be:

  •  A Steady Red Traffic Light
  •  A Flashing Red Traffic Light

i) Steady Red Traffic Light:

It is also known as the "Stop" light. A solid(steady) Red Traffic Light is the one that it continues to light up for a pre-specified time continuously without blinking. 

A solid red light gives a message to stop completely. It indicates that your vehicle should be at a complete stop to let others cross safely.

ii) What does a Flashing Red Light Mean?

A Flashing Red Light is the one when the red light is on and it is blinking (means going on and off). 

It is used at crossroads to indicate that drivers must come to a complete stop before proceeding.

If some vehicles or pedestrians are already crossing, then you must give way to them to cross safely before continuing.

2) Yellow Lights Meaning:

The yellow light can also be in two forms:

  • Solid Yellow Traffic Light
  • Flashing Yellow Traffic Light 

i) Solid Yellow Traffic Light:

If a solid yellow light is on, then it is a warning signal that the light is going to change from green to red. 

It means that is the time to slow down and be ready to stop as you are near to an intersection. 

But, if you are in the middle of a crossing and cannot stop in safely, move carefully ahead.

ii) Flashing Yellow Light Meaning:

A flashing yellow light is the one which goes on blinking for a particular time period. 

A flashing yellow signal means drivers have to slow down and proceed through the crossing with caution.

It doesn't require a complete stop like a flashing red light, but drivers should be prepared to stop if necessary. You must give way to other vehicles and pedestrians already crossing.

3) Green Traffic Light Meaning:

A green traffic light can be seen in two ways:

  • Solid(steady) Green Traffic Light
  • Flashing Green Light

i) A Steady Green Traffic Light Means:            

When the green light is on, it means you don't need to stop. You can move ahead safely through crossroads. 

In short, the green traffic light means "go". 

It gives the indication to move forward immediately, allowing a particular lane in a particular direction. 

ii) Flashing Green Light Meaning:

Flashing green light as the name sounds is the green light blinking for a pre-specified time.

It is used only in particular locations and for specific purposes. Different countries can have different meanings for it depending on their local traffic laws. 

Generally, it is used for pedestrian crossing. When it is activated, you should give a passage to the pedestrians to cross, even though the traffic light is green.

Sometimes it is also used when the traffic is low, allowing you to cross through the junction but with caution. 

Traffic Signals with Arrows:

The traffic signals with arrows provide the instructions to make turns. 

They help in improving the efficiency of traffic management and help in a smoother traffic flow.

i) Solid Red Arrow Traffic Light:

A steady red arrow means you must put your vehicle to a complete stop. You should not turn in the direction in which the arrow points. 

You must wait for a Green Arrow before you move ahead. Hence, it prevents collisions during turns.

For example, if a steady red arrow is displayed for a right turn, then the drivers should not make a right turn and they must wait for the signal to change.

ii) What does a Flashing Red Arrow Mean? 

A flashing red arrow warns you to stop once. Then determine if the intersection is clear of all pedestrians and vehicles, and then move ahead.

iii) Yellow Arrow Sign Meaning:

A steady yellow arrow indicates that the signal is going to change from green to red.

So you should prepare to stop and should not start a turn or movement.

iv) What does a Flashing Yellow Arrow Mean?

When a flashing yellow arrow is on, you can continue with caution in the direction the arrow points. 

But you should make a turn only if there are no vehicles or pedestrians at the junction.

It helps the drivers to make a safe turn without the need to come to a complete stop.

v) Green Arrow Sign Meaning:

A green arrow ensures a safe turn. When it is on, you can make a turn in a particular direction without stopping.

It ensures that the crossing is clear and safe to take a turn.

vi) Flashing Green Arrow Traffic Light: 

A flashing green arrow allows a permissive turn.

It allows you to take the turn in the pointed arrow. But for that, you must give way to the oncoming traffic and pedestrians.

The flashing green arrow indicates that the turn is allowed when there is a gap in the oncoming traffic.

A Green Arrow showing with a Red Traffic Light Means:

A Green Arrow showing with a Red Traffic Light means that a particular turn is permitted. It is applicable to a indicated lane only. 

It is used in situations where a specific lane is dedicated to a particular turn, allowing those drivers to make the turn while other lanes remain halted by the red light.

Types of Traffic Signals / Traffic Control Signals: 

The Traffic Control Signals are the ones which are used to manage the traffic flow at the crossings. It includes both the vehicular and pedestrian movements at the crossroads.

1) Manually Operated Signal: 

Manually Operated Signals are the ones that are operated by humans. These are often seen at construction sites or during special events.

2) Fixed Time Signal: 

As the name suggests, these are the signals that follow predetermined time intervals for each phase of the signal cycle.

3) Traffic Actuated Signal: 

The Traffic Actuated Signal is also known as the Demand-Responsive signal. 

It is activated as per the flow of the traffic in a particular direction. 

It facilitates adjusting the signal timings, which is based on the live traffic conditions that are spotted by the sensors.

4) What is a Pedestrian Signal?

The Pedestrian Signal is the signal for pedestrians (people walking on the roads or crossing roads).  

It informs the pedestrians when it is safe to move ahead at crossroads.

5) Special Signal/Flashing Signal: 

These are the signals that convey unique instructions, such as allowing emergency vehicles to pass or indicating railroad crossings.

6) Lane Use Control Signals:

They are used to managing the traffic flow in particular lanes or the lanes that are dedicated to a specific purpose. 

Red X:

When a red "X" is displayed over a lane, it indicates that the lane is closed and drivers must not enter it. 

The reason for may be traffic jams, maintenance activities etc.

Yellow X:

A yellow "X" indicates that the lane is about to close. 

So, drivers must prepare themselves to merge safely into adjacent lanes.

Green arrow:

A green arrow above a lane indicates that the lane is open and can be used for travelling. 

This signal may appear during high traffic volumes or for specific events.

Traffic Lights Malfunction:

Traffic lights can sometimes encounter issues that can interrupt their normal operation. 

However, these malfunctions are rare, they require careful navigation and alternative rules to maintain order on the roads.

1) Complete Outage: 

A complete power outage can render traffic lights non-functional. When such situation occurs drivers must treat affected intersections as four-way stops, taking turns based on the order of arrival.

2) Stuck Signal: 

A signal that remains stuck in one color, such as red or green, can confuse drivers and disrupt the flow of traffic. 

In this case, drivers should treat the signal as if it were operational and follow the corresponding color instructions.

3) Rapid Signal Changes: 

Rapid signal changes can lead to confusion and potential accidents. Drivers should exercise caution and proceed with care, assuming that the signal is malfunctioning.

4) Unresponsive Sensors: 

Traffic actuated signals rely on sensors to detect vehicle presence. 

If these sensors fail, drivers might experience unusually long signal cycles. In such cases, drivers should wait patiently or follow the appropriate signal for the main direction.

5) Emergency Situations: 

During emergencies, traffic lights may need to be manually controlled by law enforcement personnel. Drivers should follow their instructions and proceed with caution.

6) Alternative routes: 

In the event of severe and prolonged traffic light malfunctions, authorities may suggest alternative routes to manage traffic and avoid congested areas.

Traffic Light Rules in short:

Traffic Lights Meanings
Red Light Stop
Yellow Light Caution
Green Light Go
Flashing Red Light Stop and Yield
Flashing Yellow Light Proceed with Caution
Flashing Green Light Caution for pedestrians
Red Arrow Stop and Do Not Turn
Flashing Red Arrow Stop and Proceed with Caution
Yellow Arrow Prepare to Stop or Complete Turn
Flashing Yellow Arrow Turn with Caution
Green Arrow Allow Safe Turn
Flashing Green Arrow Specific Turn Permission

A "Phase" is the term used whenever a traffic sign changes colour or displays a protective arrow. Each phase is timed, allowing traffic to move safely and effectively.

A "cycle length" is the total time it takes to serve all of the signal phases, including the green time and clearance intervals.    

Precautions To Follow At Traffic Signals:

Some precautions must be followed to ensure the well-being of all the road users and promote a secure and orderly flow of traffic at crossings.

1) Obey Signal Instructions: 

Everyone at the crossing must follow the instructions of the traffic signals strictly.  Stop at red lights, go at green lights, and have caution at yellow lights.

2) Maintain Safe Stopping Distance: 

Leave adequate space between your vehicle and the one in front, ensuring you can come to a complete stop safely.

3) Yield to Pedestrians: 

At crossing, even if the green light is on, one must give a way for the pedestrians to cross. Stop behind the crosswalk to allow safe passage.

4) Avoid Distracted Driving:

Focus on the road and avoid distractions like texting, talking on the phone, or adjusting devices while waiting at traffic lights.

5) Check Intersection Clearances:

Ensure that the intersection is clear of any obstructions or stalled vehicles before proceeding.

6) Use Turn Signals: 

Indicate your intentions with proper turn signals to alert other drivers and pedestrians of your planned actions.

7) Adapt to Road Conditions: 

Adjust your driving speed based on road conditions, weather, and visibility to maintain control and prevent skidding.

8) Be Cautious of Oncoming Traffic: 

When making turns or proceeding through an intersection, be aware of oncoming traffic and ensure it's safe to proceed.

9) Avoid Blocking Intersections: 

Ensure you can clear the intersection completely before entering it, preventing gridlock and traffic congestion.

10) Stay Patient: 

Exercise patience and remain calm, especially during heavy traffic. Avoid aggressive behaviors that can escalate situations.

11) Watch for Cyclists: 

Be vigilant for cyclists and share the road with them, especially when making turns.

12) Emergency Vehicles: 

Yield to emergency vehicles with lights and sirens, allowing them to pass safely.

13) Observe Pedestrian Signals: 

Follow pedestrian signals if you're walking or biking, ensuring your safety while crossing.

14) Stay Prepared: 

Be ready to react to unexpected situations or the actions of other drivers, even when the light changes.

        Understanding the traffic lights and the meaning of their colors is important for on the smooth crossings on roads.