Designing a Crosswalk Light System
Date: Fall 2025
Author's Name: Designer and Dr. David Burghardt
Grade level: 7/8
Content or Subject Area's: Informed engineering design with computer science and computer control
Duration of lesson: 6 days
General Objectives: Students will design, construct and program an automated crosswalk light system that calculates pedestrian crossing times and vehicle stopping distances, integrating mathematical analysis of motion, sensor programming, and engineering design principles to create a traic safety system with appropriate timing sequences.
Learning Outcomes: What knowledge, skills, and strategies do you expect students to gain?
(1-4 stated outcomes) After completion of the lessons, students will be able to: (use action verbs)
1. Use the informed engineering design process
2. Apply mathematical concepts including speed, distance, and time calculations to determine optimal signal timing for vehicle deceleration and pedestrian crossing safety.
3. Program sensor- controlled systems using conditional logic and timing sequences to automate traic light responses based on pedestrian activation inputs.
4. Design, construct, and test an integrated safety system that combines mathematical analysis, sensor programming, and user interface design to solve real-world transportation challenges.
State Standards: (NY Computer Science & Digital Fluency Standards) End of Grade 8:
7-8.CT.4: Write a program using functions or procedures whose names or other documentation convey their purpose within the larger task
7-8.CT.6: Design, compare and refine algorithms for a specific task or within a program
7-8.CT.7: Design or remix a program that uses a variable to maintain the current value of a key piece of information
7-8.CT.8: Develop or remix a program that eectively combines one or more control structures for creative expression or to solve a problem
7-8.NSD.2: Design a project that combines hardware and software components
National standards: (ITEEA STEL Standards) End of the 8th Grade:
Standard 1: Students will develop an understanding of the characteristics and scope of technology while learning that technology is the result of human activity; technology is closely linked to creativity and ingenuity.
Standard 3: Students will develop an understanding of engineering design and will learn that engineering design is guided by brainstorming, visualizing, modeling, constructing, testing, and refining designs.
Standard 8: Students will develop an understanding of the attributes of design and will learn that design is a creative planning process that leads to useful products and systems.
Standard 17: Students will develop an understanding of and be able to select and use information and communication technologies including programming systems to control automated devices.
Materials and Resources: Provide a list of materials and resources needed to teach the lesson
Physical Materials: Cardboard strips, tape, Hummingbird LED lights (single- color and tricolor), Hummingbird light sensors, glue gun, scissors, markers and art supplies for crosswalk design, computers with Snap programming software, Hummingbird controllers
Resources: Traic engineering standards and guidelines, pedestrian safety research, sensor programming tutorials, timing calculation worksheets, real-world crosswalk system examples, BirdBrain Technologies programming guides
Focusing Event: Students observe and analyze real crosswalk systems during a brief outdoor investigation or through video examples, noting the timing sequences, light patterns, and safety features. Discussion: "Why don't crosswalk lights change immediately when you press the button? How do traic engineers calculate the right timing to keep both pedestrians and drivers safe?" This introduces the real-world engineering problem of designing automated safety systems that must account for human reaction times, vehicle physics, and pedestrian mobility needs.
Day by day plan
Day 1: Specifications and Constraints (40 minutes) Informed Design Phase: Specifications and Constraints
• Introduce challenge: Design an automated crosswalk system that ensures pedestrian safety through proper timing calculations
• Review project specifications: system must allow time for vehicle stopping, pedestrian crossing, and warning phases
• Discuss constraints: 30-foot street width, 35 mph traic speed, 4 ft/second pedestrian walking speed, available LED and sensor components
• Introduce assessment rubric and informed engineering design process
• Students complete KSB 1: Preliminary design concepts for crosswalk systems
• Students document initial understanding of traic safety requirements and timing constraints
Day 2: Developing Knowledge - Mathematical Analysis of Traic Safety (40 minutes)
Informed Design Phase: Developing Knowledge
• Learn speed, distance, and time relationships in traic engineering contexts
• Understanding vehicle reaction times, braking distances, and pedestrian crossing calculations
• Students complete KSB 2: Crossing time calculations including driver reaction time and stopping distance mathematics
• Practice converting units (mph to ft/sec) and applying physics concepts to safety engineering
• Calculate optimal timing sequences for dierent traic scenarios and pedestrian populations
Day 3: Developing Knowledge - Sensor Programming and LED Control (40 minutes)
Informed Design Phase: Developing Knowledge (continued)
• Learn light sensor operation and threshold programming for pedestrian activation
• Understanding LED programming for steady and blinking light patterns
• Students complete KSB 3: Sensor operation programming with light sensor triggering LED responses
• Practice programming timing delays and sequential light control systems
• Explore conditional logic and variable management for state-based systems
Day 4: Ideate Solutions - System Design and Algorithm Development (40 minutes)
Informed Design Phase: Ideate Solutions
• Students sketch minimum of 3 alternative crosswalk system designs considering user interface and safety features
• Consider dierent light arrangements, sensor placements, and visual communication approaches
• Students complete KSB 4: Algorithmic thinking and pseudocode development for crosswalk sequence control
• Document various timing approaches and safety enhancement strategies
• Brainstorm accessibility features and diverse user needs considerations
Day 5: Build Prototype - Integration and Programming (40 minutes) Informed Design Phase: Build Prototype
• Construct physical crosswalk system using cardboard, LEDs, and sensors
• Program complete crosswalk control algorithm integrating timing calculations with sensor inputs
• Test individual components and debug integration between mathematical timing and hardware responses
• Validate system performance against calculated timing requirements and safety specifications
• Document construction challenges and programming refinements needed
Day 6: Test, Evaluate, and Refine Design (40 minutes) Informed Design Phase: Test and Evaluate Design + Refine Design
• Complete the assessment rubric self- evaluation from day 1 and justify their selfassessment
• Reflect on the informed engineering design process and lessons they learned