Traffic Signal W/ Night-time Flashing

I am looking for a help on a project that will simulate a traffic signal normally during daylight hours and then switch to f lashing lights (N/S- yellow, E/W- red) at night. I have thought of going at it in two ways, 1. using gates, counters, flip-flops, and possibly a GAL to ensure that both green lights will not come on at the same time.(program it to shut power down if that were to happen), 2. using a counter, Gal, a 2 quad mux. the only thing is I need to use at least 8 chips in the design.Here is the time frames that I would like to use: N/S- green for 5s, yellow - 1s, red- 6s E/W- 6s, green-5s, yellow- 1s. Also I need the night time flashing only to occur at the final count of 11 when it is dark outside. If anyone can help please send the circuit schematic with all components labeled.

Thanks
Otty127

I would stongly suggest you use a micro-controller instead, it's a trivial job for a PIC, and would only take a single cheap chip.

Please send the address of your professor so we can be sure you are given proper credit for your 'work'.