Prposed circuit...

It doesn't do anything fancy, but then again it is done with ni pic's or even any chips at all... just a basic condensor, resitor based astable-multivibrator.

The turn signal will switch about 10 times per second. So that's 5 times per second for each light.

With the light's on the led run at a little under 10 mA... About half power...

With the brakes pressed it will increase the current to 22mA, for brighter light.