Big Numbers, Real Data
“Three hundred twenty-nine.” “No! Twenty-eight!” A traffic count going on outside a school can yield some large numbers and opportunities for many
questions. If the count goes on over a period of time, do students see variations in the number of cars per hour, or even per fifteen minutes? If I count forty cars in fifteen minutes, can I multiply that by four to get an hourly rate? How could I compute a rate for twenty-four hours? The frequency of traffic must be very different by
9:00 PM and different still at 3:00 AM. Traffic counts are used by professional planners and transportation officials to study the need for new
or wider roads, or the need for repaving, or the impacts of development. Students can use them, too, for the math possibilities and for social studies discussions of all sorts. Change over time is a concept that can be illustrated nicely by traffic counts. Sitting outside the school, or watching from a window of the school remains a great way to get basic
information and to practice careful observation and counting. That also allows for debate: Do we want to count cars going one way as distinct from the opposite direction? Do we want to distinguish between cars and trucks and, perhaps, bicycles? New opportunities now include: How could we use a webcam? What would be the best way to
incorporate a motion detector or a photogate linked to a computer to do more counting for us? All these are possibilities for data collection that can either replace counting one-by-one or augment that counting. Your state Agency of Transportation offers another avenue through their online records of traffic
counts at different sites (those rubber tubes that are set up across roads, or sensors embedded in pavement) and webcams that show current traffic density. Check your Agency or Department of Transportation online. City and county data can also be used for comparisons. Here’s one example that offers you traffic cameras throughout the city of Spokane, Washington.
SYNERGY LEARNING INTERNATIONAL, INC.
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Volume 24 • Issue 5 May • June 2011
Innovations in K–8 Science, Math, and Technology