The Arduino Pro Mini used to control the traffic light is not only responsible for playing the tones through a piezo speaker, but as you might expect, for firing off the relays which ultimately ...

Nothing comes close to the awesomeness of this traffic light server monitoring system which has been created using a little Arduino wizardry ...

For those starting out in Arduino, there are tons of resources to get better acquainted with the community and the types of projects you can tinker with.