Stop and Go

This lesson focuses on how engineers have developed and improved traffic management over time. Students work in teams to design a new traffic light system.

  • Learn about traffic engineering.
  • Learn about engineering design and redesign.
  • Learn how engineering can help solve society’s challenges.
  • Learn about teamwork and problem solving. 

Age Levels: 8-18

Build Materials (For each team)

Required Materials

  • Student Worksheet
  • Paper/Pen

Design Challenge

You are part of a team of engineers given the challenge of designing an improved traffic light system.  The downtown area of BusyCity has a particularly busy intersection that includes two roads with heavy traffic, a bicycle lane, cross walks, and also the ambulance entrance to a hospital emergency room.  Too often, ambulances have to wait for the lights to change which delays transporting a patient for quick care.  Also, bicycles are often unable to cross the intersection because they have to wait for cars to let them go.

  1. Break class into teams of 3-4.
  2. Hand out the Stop and Go worksheet, as well as some sheets of paper for sketching designs.
  3. Discuss the topics in the Background Concepts Section. Consider asking the students what driving would be like without traffic signals. Ask them to observe those in their town and consider how they work, and to see if any of the ones in their town have enhancements such as special signals for bicycle lanes or joggers.
  4. Review the Engineering Design Process and Design Challenge.
  5. Explain that students must review the challenge and design an improved traffic light signal to solve the problem.
  6. Announce the amount of time they have to design (1 hour recommended).
  7. Use a timer or an on-line stopwatch (count down feature) to ensure you keep on time. (www.online-stopwatch.com/full-screen-stopwatch). Give students regular “time checks” so they stay on task. If they are struggling, ask questions that will lead them to a solution quicker.
  8. Students meet and sketch a design for their traffic light system. They should consider the cost of the redesign compared to the standard traffic light system.
  9. Teams share their designs with the class and give an estimate of how the new light might impact the cost of one light.
  10. As a class, discuss the student reflection questions.
  11. For more content on the topic, see the “Digging Deeper” section.


Extension Idea

Have students build a working model of their traffic system using lights, switches, wiring, and other sensors.


Student Reflection (engineering notebook)

  1. What was the most interesting proposed change to the traffic light that was developed in your class presentations? Why?
  2. Do you think that your design would increase or decrease the cost of manufacturing a traffic signal? Why?
  3. Do you think your new traffic light would have a market if manufactured? Who would buy it, and why?
  4. Do you think that you could raise funds to pay for manufacturing? How would you go about raising funds?
  5. Do you think that many engineers reinvent products or systems based on new technology or current needs? Can you provide an example of a product or system that has been re-engineered many times?
  6. Did you think that working as a team made this project easier or harder?  Why?

Time Modification

The lesson can be done in as little as 1 class period for older students. However, to help students from feeling rushed and to ensure student success (especially for younger students), split the lesson into two periods giving students more time to brainstorm, test ideas and finalize their design. Conduct the testing and debrief in the next class period.

Divide into teams
Review the challenge and criteria constraints
Brainstorm possible solutions (sketch while you brainstorm!)
Choose best solution and build a prototype
Test then redesign until solution is optimized
Reflect as a team and debrief as a class

History of Traffic Lights 

jgroup-bigstock.com

What is a Traffic Light?

Traffic lights, which may also be known as stoplights, traffic lamps, traffic signals, or semaphores, are signaling devices positioned at road intersections, pedestrian crossings and other locations to control competing flows of traffic. Traffic lights have been installed in most cities around the world. They assign the right of way to road users by the use of lights in standard colors (red – amber/yellow – green), using a universal color code and a precise sequence. Usually, the red light contains some orange in its hue, and the green light contains some blue, to provide some support for people with red-green color blindness.

Traffic Engineers

Traffic engineering is a branch of civil engineering that uses engineering techniques and develops mechanisms that achieve the safe and efficient movement of people and goods on roadways. It focuses mainly on research and construction of the infrastructure necessary for safe and efficient traffic flow, such as road geometry, sidewalks and crosswalks, segregated cycle facilities, shared lane marking, traffic signs, road surface markings and traffic lights. Typical traffic engineering projects involve designing traffic control device installations and modifications, including traffic signals, signs, and pavement markings. However, traffic engineers also consider traffic safety by investigating locations with high crash rates and developing countermeasures to reduce crashes. Traffic flow management can be short-term (preparing construction traffic control plans, including detour plans for pedestrian and vehicular traffic) or long-term (estimating the impacts of proposed commercial developments on traffic patterns). Increasingly, traffic problems are being addressed by developing systems for intelligent transportation systems, often in conjunction with other engineering disciplines, such as computer engineering and electrical engineering.

Traffic Light History

The earliest known traffic signal dates to London in 1868, well before automobiles clogged the streets. The signal was a revolving lantern that flashed red lights (for stop) and green lights (for caution) which was illuminated by gas and operated by hand. The design was a bit flawed as the light exploded in 1869, injuring the policeman-operator. As early as 1912 in Salt Lake City, Utah, a policeman named Lester Wire invented the first red-green electric traffic light. In 1914, the American Traffic Signal Company installed a traffic signal system on the corner of East 105th Street and Euclid Avenue in Cleveland, Ohio. It had two colors, red and green, and a buzzer, to provide a warning for color changes. The first four-way, three-color traffic light was created in Detroit, Michigan in 1920.

Internet Connections

Recommended Reading

  • Principles of Highway Engineering and Traffic Analysis (ISBN: 978-0470290750)
  • Traffic Engineering (ISBN: 978-0136135739)

Writing Activity

Write an essay or a paragraph about what driving might be like without traffic signals.

Alignment to Curriculum Frameworks

Note: Lesson plans in this series are aligned to one or more of the following sets of standards:  

National Science Education Standards Grades K-4 (ages 4-9)

CONTENT STANDARD A: Science as Inquiry

As a result of activities, all students should develop

  • Abilities necessary to do scientific inquiry 
  • Understanding about scientific inquiry 

CONTENT STANDARD E: Science and Technology 

As a result of activities, all students should develop

  • Abilities of technological design 
  • Understanding about science and technology 

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

  • Science and technology in local challenges 

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

  • Science as a human endeavor 

National Science Education Standards Grades 5-8 (ages 10-14)

CONTENT STANDARD A: Science as Inquiry

As a result of activities, all students should develop

  • Abilities necessary to do scientific inquiry 
  • Understandings about scientific inquiry 

CONTENT STANDARD E: Science and Technology

As a result of activities in grades 5-8, all students should develop

  • Abilities of technological design 
  • Understandings about science and technology 

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

  • Populations, resources, and environments 
  • Risks and benefits 
  • Science and technology in society 

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

  • Science as a human endeavor 
  • Nature of science 
  • History of science

National Science Education Standards Grades 9-12 (ages 14-18)

CONTENT STANDARD A: Science as Inquiry

As a result of activities, all students should develop

  • Abilities necessary to do scientific inquiry 
  • Understandings about scientific inquiry 

CONTENT STANDARD E: Science and Technology

As a result of activities, all students should develop

  • Abilities of technological design 
  • Understandings about science and technology 

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

  • Personal and community health 
  • Science and technology in local, national, and global challenges 

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

  • Science as a human endeavor 
  • Nature of scientific knowledge 
  • Historical perspectives 

Next Generation Science Standards Grades 2-5 (Ages 8-11)

Engineering Design 

Students who demonstrate understanding can:

  • 3-5-ETS1-1.Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.
  • 3-5-ETS1-2.Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.

Next Generation Science Standards Grades 6-8 (Ages 11-14)

Engineering Design 

Students who demonstrate understanding can:

  • MS-ETS1-2 Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.

Next Generation Science Standards Grades 9-12 (Ages 14-18)

Engineering Design 

Students who demonstrate understanding can:

  • HS-ETS1-2.Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering.

Standards for Technological Literacy – All Ages

The Nature of Technology

  • Standard 1: Students will develop an understanding of the characteristics and scope of technology.
  • Standard 2: Students will develop an understanding of the core concepts of technology.

Technology and Society

  • Standard 4: Students will develop an understanding of the cultural, social, economic, and political effects of technology.
  • Standard 5: Students will develop an understanding of the effects of technology on the environment.
  • Standard 6: Students will develop an understanding of the role of society in the development and use of technology.
  • Standard 7: Students will develop an understanding of the influence of technology on history.

Design

  • Standard 8: Students will develop an understanding of the attributes of design.
  • Standard 9: Students will develop an understanding of engineering design.
  • Standard 10: Students will develop an understanding of the role of troubleshooting, research and development, invention and innovation, and experimentation in problem solving.

Abilities for a Technological World

  • Standard 11: Students will develop abilities to apply the design process.
  • Standard 13: Students will develop abilities to assess the impact of products and systems.

Engineering Teamwork and Planning

You are part of a team of engineers given the challenge of developing an proposal to meet the needs of a potential client.  The downtown area of BusyCity has a particularly busy intersection that includes two roads with heavy traffic, a bicycle lane, cross walks, and also the ambulance entrance to a hospital emergency room.  Too often, ambulances have to wait for the lights to change which delays transporting a patient for quick care.  Also, bicycles are often unable to cross the intersection because they have to wait for cars to let them go.  The town would like you to develop a plan to technically enhance the simple “green, yellow, red” traffic light to help alleviate the problems the ambulances and bicycles encounter.

As a team, consider the challenge and agree on a system to adapt the traffic signal to meet the challenge.

Research Phase

Read the materials provided to you by your teacher. If you have access to the internet, you can also research ideas online, then work as a team to develop a plan.  Your plan will be both written and presented to the client (your class), and you may choose to use presentation software such as PowerPoint, or create posters, or paper handouts.

Design Phase

On a separate piece of paper draw a detailed diagram showing how what changes you would engineer into the traffic light.  Be specific and include a list of parts or materials you might need to purchase if you were to build a prototype of the traffic light.  Make an educated guess as to how the revisions might increase or decrease the cost of manufacturing a traffic light.

Presentation Phase

Present your ideas, drawings, and proposed new traffic light to the class, the complete the reflection sheet.

Reflection

Complete the reflection questions below:

  1. What was the most interesting proposed change to the traffic light that was developed in your class presentations? Why?

 

 

 

 

 

 

  1. Do you think that your design would increase or decrease the cost of manufacturing a traffic signal? Why?

 

 

 

 

 

 

  1. Do you think your new traffic light would have a market if manufactured? Who would buy it, and why?

 

 

 

 

 

 

  1. Do you think that you could raise funds to pay for manufacturing? How would you go about raising funds?

 

 

 

 

 

 

  1. Do you think that many engineers reinvent products or systems based on new technology or current needs? Can you provide an example of a product or system that has been re-engineered many times?

 

 

 

 

 

 

  1. Did you think that working as a team made this project easier or harder? Why?

 

 

 

 

Lesson Plan Translation

Downloadable Student Certificate of Completion