Help Prevent Speeding, Help Save Lives: A Math Lesson About Driving Safety

• Speeding + Stopping Distance = Danger Activity Sheet printable
• Pencils
• Whiteboard and markers
• Computer with Internet access
• Projector

1. Make a class set of the Speeding + Stopping Distance = Danger Activity Sheet printable.
2. Preview the public service announcement (PSA) videos on the National Road Safety Foundation website to determine whether they are appropriate for your class.
   • Life Is Not a Race, Go Your Own Pace (60 seconds)
   • Mom in a Hurry (30 seconds)
   • Waterbugging (30 seconds)

Step 1: To help students make a connection with the causes and effects of speeding when driving, have them first examine their own behaviors and cite examples of when they rush or are in a hurry and what happens. Ask students:

• What are some examples of times when you have rushed or been in a hurry?

Answers might include rushing to get to class or practice on time, to get home before curfew, to finish an assignment or test, etc.

• In these examples, why did you rush?

Running late, to get somewhere on time, to finish on time, to avoid getting into trouble, to just be done with a task.

• Have you faced any negative consequences as a result of rushing?

Students might identify consequences associated with being distracted when rushing, such as bumping into things and not being aware of what’s going on around them, as well as other consequences, such as not doing well on a test or an assignment, etc.

• What are some other examples of when people rush?

Answers may include driving.

Step 2: Write “speeding” on the board and ask students to describe what speeding means and what they think of when they read the word. While your students may not be drivers, they have likely witnessed drivers who speed or exceed the speed limit.

Step 3: Organize students into teams of three to five students. Ask each group to create two lists. On one list, students should identify reasons drivers might speed. On the other list, students should brainstorm the possible consequences of speeding.

Step 4: Invite the groups to share the causes of speeding they brainstormed and write them on the board. Compare the teams’ lists. Responses may include:

• Driver is late or in a rush.
• There’s an emergency.
• Driver is distracted and not paying attention to his or her speed.
• Driver is angry or upset.
• Driver is keeping up with traffic flow.
• Driver just enjoys going fast.
• Driver overestimates his or her abilities to control the car.

Step 5: Ask students to identify the potential consequences of speeding they came up with and write them on the board. Answers may include:

• Not having enough time to stop
• Losing control of the car
• Car crashes, rear-end collisions
• Driver weaves through traffic
• Tailgating
• Braking hard or swerving to avoid crashes
• Being distracted
• Speeding tickets
• Underestimating road conditions
• Not seeing potential obstacles on the road until it’s too late

Step 6: Share these facts from the National Highway Traffic Safety Administration with students:

• In the United States in 2015, 27% of people killed in fatal car crashes were in a crash involving at least one driver who was speeding. That’s 9,557 lives. (From: NHTSA’s National Center for Statistics and Analysis, “Traffic Safety Facts—2015 Data: Speeding,” July 2017.)
• The highest percentage of these fatalities are young drivers ages 15 to 24, especially males. (From: National Highway Traffic Safety Administration, “Safety in Numbers,” August 2015.)

Step 7: Ask students:

• What factors impact how far a car travels before stopping?

List the responses on the board.

Step 8: Explain to students that stopping distance includes the following:

• The driver’s reaction time: this is the time it takes for the driver to perceive a need to stop and decide what to do before placing his or her foot on the brake. The car continues to cover ground while the driver reacts. This is reaction distance.
• Braking time: a few elements impact the car’s ability to slow down and come to a halt, including the car’s weight and tire conditions, road conditions—whether the pavement is dry, wet, icy, or slushy—and speed. The distance the car travels between the time the driver puts on the brakes and the time the car stops is braking distance.
• The faster the speed, the longer it takes for the car to come to a stop, and the farther the distance the car travels before stopping.

Step 9: Distribute copies of the Speeding + Stopping Distance = Danger Activity Sheet printable. Review the instructions and examples with students, and then have them complete the page independently or in small groups. Review the answers together. Each number is rounded to the nearest whole number.

Speeding + Stopping Distance = Danger Activity Sheet Answer Key

1. A car is traveling 55 mph. Another car stops in front of it.

a. It takes the driver 1.5 seconds to react. What’s the reaction distance? 

Answer: 122 feet

Calculating the response:

55 mph x 5,280 feet per mile = 290,400 feet per hour

290,400 ÷ 3,600 seconds per hour = 80.667; round to 81 feet per second

81 x 1.5 seconds = 121.5; round to 122 feet

b. The pavement is dry. The car begins to slow. It travels another 144 feet in braking distance before stopping. What’s the total stopping distance on dry pavement? 

Answer: 266 feet

Calculating the response:

122 feet + 144 feet = 266 feet

c. Add 39 feet for wet roads. What’s the stopping distance now?

Answer: 305 feet

Calculating the response:

122 feet + 144 feet + 39 feet = 305 feet

2. A car is speeding at 70 mph. The driver sees something blocking the road.

a. The reaction time is 1.5 seconds. What’s the reaction distance?

Answer: 155 feet

Calculating the response:

70 mph x 5,280 = 369,600 feet per hour

369,600 ÷ 3,600 seconds per hour = 102.667 feet; round to 103 feet per second

103 x 1.5 seconds = 154.5 feet; round to 155 feet

b. The braking distance as the car decelerates on dry pavement is 233 feet. What’s the stopping distance?

Answer: 388 feet

Calculating the response:

155 feet reaction distance + 233 feet braking distance = 388 feet

c. Now imagine that the driver is distracted. It takes the driver 3 seconds to react. What’s the reaction distance?

Answer: 309 feet

Calculating the response:

103 feet per second x 3 seconds = 309 feet

d. Assuming the same 233 feet braking distance, what’s the stopping distance?

Answer: 542 feet

Calculating the response:

309 feet reaction distance + 233 feet braking distance = 542 feet

e. How does each stopping distance compare to a football field?

Answer: The stopping distance is greater than the length of a football field.

3. What are the potential risks for a driver who is speeding and attempting to stop the car?

Answer: Not stopping on time; crashing into the car in front of them; running off the road; hitting an obstacle in the road; causing other drivers who are trying to get out of the way to crash, etc.

Step 10: Reinforce students’ understanding of the distance presented in the examples and math problems by having them measure the reaction, braking, and stopping distances in a hallway or on the school’s track or ball field. Ask students:

• The stopping distance for a driver who is speeding or going above the speed limit is greater than someone going the speed limit. What unexpected issues might someone who is speeding experience while trying to stop?

Step 11: Shift discussion from drivers to passengers. Your students may be passengers in vehicles driven by siblings or friends who exceed the speed limit. Ask students:

• If you’re in a car with a friend or sibling who is driving too fast, what do you do? Do you say anything?
• What could you say or do if the driver is speeding?

Step 12: Discuss the barriers or why people or passengers may not speak up when in a car with a driver who is speeding. Then ask students what they could do or say if they are in a car with a friend who is speeding, don’t feel safe, and want to get out of the situation. Share these ideas with students:

• Don’t get in the car with a friend who drives fast.
• Speak up — if your friend is driving too fast, tell him or her to slow down.
• Tell your friend you don’t feel comfortable.
• Tell your friend his or her driving is not safe.
• Ask your friend to pull over so you can get out if he or she doesn’t slow down.
• Call your parents for a ride.

Step 13: Ask students what messages they think would resonate with drivers to help prevent speeding based on the information they’ve learned about the potential causes and consequences of speeding.

Step 14: Consider viewing one or more of the public service announcement (PSA) videos on the National Road Safety Foundation website and ask students to evaluate the message, visual approach, and effectiveness of the PSA. Please preview the videos before sharing them with students to determine whether they are appropriate for your group.

• Life Is Not a Race, Go Your Own Pace (60 seconds)
• Mom in a Hurry (30 seconds)
• Waterbugging  (30 seconds)

Step 15: Encourage students to research additional facts on speeding and use the information to develop a storyboard or script for a PSA to help prevent speeding for the 2018 Drive2Life Contest.

Skills supporting learning standards:

• Making inferences
• Analyzing informational text
• Solving real-world math problems
• Participating in group discussions