Cycling T-shirt Design

Hey All,

I am doing a design for the back of a t-shirt I want to print, I am planning a 110 mile trip and I wanted to create a Yeild Sign design to warn drivers of my presence on the road. I want to create something retro, and unique. This is what I have and I am not happy with it at all, I was wondering if any of you would have any suggestions I could try, colors, shapes, etc…

Thanks for your input in advance.