Hi jude,
It has long been a challenge to me,
since student days,
to construct a simple three LED traffic light set,
red LED, amber LED, green LED,
using the minimum number of components possible.
I have made many such units,
some free running with intervals up to about seven
seconds, and some not free running which change state
from a press-button.
It is this latter type using a press button that i have
managed to reduce to less than twelve discrete
components.
It may be possible to do it with even fewer components,
but i have not managed it yet.
Best of luck with your studies, i would be most
interested to see how you get on.
Regards, John