@orcrist@rusted yes, there should be some regulation, but flat illegal is pushing things in awkward directions.
The answers are probably pretty minimal, these are speeds that we are happy for cyclists to be doing with nothing more than a polysytrene hat, the sanity of the PPE that road cyclists use is a valid question.
Something like requiring better brakes, maybe dual independent front brakes, would probably be enough. Requiring head/tail/indicator lights would also be reasonable.