Bike Turning Signal Circuit

I am coming back to electronics, so I am a bit of a noob. I am making plans/developing ideas for a 12v lighting and turn signal system for a bicycle. For the Bike Turning Signal Circuit, I assume that a 556 could be used instead of 2x555s, so 2x556 could be used for both front and rear. My question is this: I would also like to have 4-way/hazard flashing using the same LEDs--what would be a good way of going about this?

Thank you.