Helmet nazis often use the same non-argument. Stating that something is "obvious" or "trivial" is "proof by assertion" -- the most basic logical fallacy..

And the question is not trivial because, contrary to the strawmen being built here, no one is arguing for riding without lighting in the pitch dark on a bumblefrack rural highway. In well-lit urban areas there is surprisingly little evidence that riding without lighting is particularly risky. Thus far, you have only brought bluster and ad hominems to this discussion. It would be nice if you could attempt to actually develop a coherent argument (stating that it's obvious or trivial is not an argument) and provide some evidence or data to support your argument.

In a previous thread I linked to several studies that attempted to measure the risk of riding without lighting in urban areas. Surprisingly, in urban areas the risk of riding without lighting was low or difficult to measure (e.g. non-trivial):

http://www.bikeforums.net/advocacy-s...ban-areas.html