There are good reasons for not making helmets required. See e.g. this overview: ...

		ar-jan on Jan 1, 2015 \| parent \| context \| favorite \| on: Junction design in the Netherlands [video] There are good reasons for not making helmets required. See e.g. this overview: Bicycle helmets and the law, http://www.bmj.com/content/346/bmj.f3817.full