One other question, the diagram uses a set of LEDs(Red Yellow Green) for both north and south and one for east and west, I can just series another 'set' of LEDs? A problem I believe the 555 only lets 200mA of current through correct? But in this case it shouldn't be a problem since at most 4 LEDs should be on at the same time?
Edit since I am adding another 2 sets of lights, should I upgrade the cap to 20uf? And the cap should be 9Vs?
Oh and since I'll be adding a second set of LEDs, I will probably use a 'gate' instead of the diodes, is one gate good for 2 sets of LEDs(N/S or E/W, 2 gates total) or should each set of leds get its own gate(N S E and W all separate, 4 gates total)?