PICAXE "snap connector" kids microcontroller kit!

Step 19 Traffic lights?!

Almost everyone has experienced the sequenced action of traffic lights, so these make for a realistic simulation. The momentary push switch even allows pedestrians to interrupt the traffic flow (yeah- eventually- just like the real thing...), and the "Cross Now" buzzer sounds ONLY when the lights are red. The basic code, of only ~a dozen lines, is hosted at http://www.picaxe.orcon.net.nz/pedx.bas

All manner of "what if" tweaks can be investigated- perhaps an "amber before green" alert that's used in some countries, or an increasingly urgent "hurry up" buzz  for pedestrians ?   Check http://en.wikipedia.org/wiki/Traffic_light#Light_timing_length for insights !