Up to a certain point, there isn't much you can do as part of this can be due to the driver doing something else while driving like surfing on internet, reading, eating, putting some make-up or whatever...

You can try this selective attention test:
http://www.youtube.com/watch?v=IGQmdoK_ZfY

My best bet would be an active light source rather than a passive one. Put on some powerful blinking lights.

If you go for some passive light sources put them on the moving area like your legs and the bicycle wheels