Wearing a helmet while riding a bicycle can be a good idea in some situations. But in Australia we have a law that says we must. Using sun-cream while outside can be a good idea in some situations. Avoiding fatty foods can be a good idea too, but we don't have laws about these. Why is that? Bicycle use had fallen significantly since the law was introduced and car usage has risen. Shouldn't we be doing everything we can to encourage bicycles, not discourage them?