Activity: Counting Cars

How busy is a road? In this activity we'll collect real data by counting how many cars pass by. Important: Make sure you do the counting from a safe place, well away from traffic.

Step 1: Make a Prediction

Before you start counting, have a think.

Why do you think that?

• Is it a busy road or a quiet one?
• What time of day is it?
• Is it a school day, weekend, or holiday?

Step 2: Choose a Time to Count

Choose a short time period to count cars, such as:

• 10 minutes (then multiply by 6 to estimate cars per hour)
• 15 minutes (then multiply by 4 to estimate cars per hour)

Try to count during a time when cars are moving normally (not stopped at traffic lights).

Step 3: Count the Cars

Use Tally Marks to help you keep count

Use the table below to record your data.

Step 4: Calculate Cars Per Hour

Now use your total to estimate how many cars would pass in one hour.

• If you counted for 10 minutes: multiply by 6
• If you counted for 15 minutes: multiply by 4

Enter the values in the table.

Step 5: Compare Prediction and Result

Think about these questions:

• Was your prediction higher or lower than the result?
• Why do you think they were different?
• Would the number change at a different time of day?

Try This Too

• Count again at a different time of day
• Compare a busy road and a quiet road
• Count different vehicles: cars, buses, trucks, bicycles

Class Activity

If everyone counts at a different time, the results can be combined into a Line Graph to show how traffic changes during the day.