Tough crowd! Keep in mind that the specs for this hypothetical traffic light system were dictated by the instructor, to be implemented with DISCRETE GATES, to demonstrate that the student can work with them. It's clearly not meant to be a real world traffic control system.
It's trivial with an Arduino. Give credit to the OP for convincing his professor to let him do it that way.
As for Fritzing, the less said, the better.