According to county guidelines, yellow lights should be on one second for every 10 miles per hour of the speed limit. With a 45-mph limit on Collier Boulevard, the yellow light should have been on for 4.5 seconds. Instead, it was only about 3.8 seconds, Mogil said.
So I'm thinking about an ongoing classroom project, something that includes a wall map of the county, push-pins marking off claimed intersections, students collecting data with stopwatches or cameras, developing (what seems to them) a fair algorithm for the duration of yellow lights, then researching the county code to determine the actual algorithm, finally marching down to city hall to call the mayor on the carpet (if need be) for his reckless disregard for public safety in pursuit of a little extra revenue.
The math isn't terribly difficult here — algorithm development, some discussion of domain, data visualization — but it's the sort of project a) that takes place largely outside of class, and b) that stitches a class together, united against The Man, in a way that's hard to reconcile with the usual instructional value calculus. (ie. how many hours of class time would you spend to create this kind of community out of your classroom? At their twenty-year reunion, will your students remember their investigation of cylinder surface area or the time they brought down city hall?)
Also, I should point out that the first thing I did when I rolled into Kannapolis, North Carolina, last Monday was shoot video of twenty traffic lights. Because I am often little more than a breathing apparatus and a set of limbs for whatever muse puts these ideas in front of me and I have to keep her happy.