The Guardian has an interesting piece which takes to task the claim that a high-visability piece of clothing is always going to make you more visible.

Now I think the point that contrasting with your environment is vital. That reflective garb or “high-viz” garb did not always produce sufficient contrast and therefore was insufficient as a means of ensuring visibility — is something that every rider should keep in mind. While this may not be so vital in cities with strong numerical presence for cyclists, in places where we are still outnumbered, and especially where we are riding with motorized traffic, this information is vital. I do not want people feeling like they have to dress like a lycra-clad demon to ride. I just want them to ride.

Why cycling in high-vis may be not as safe as you think | Peter Walker | Environment |