I read somewhere on some forum, but can't remember where to find it, that the government will soon be mandating squared off roofs on new buses? Am I right or is it non-squared off roofs?
FMVSS requirements are for the most part performance requirements so mandating a shape would not be something they would do. Now a certain shape may lend itself to compliance to a performance standard but to the best of my knowledge no new standards targeting construction are forthcoming.