Complex sentence: DOT laws vary by state, but for the most part minibikes are illegal for use on public roadways because most do not carry the necessary equipment (and often size requirements) to be street legal.
Split into simpler sentences: DOT laws vary by state, but for the most part minibikes are illegal for use on public roadways because most do not carries out the best. The other side the necessary equipment (and often size requirements) to be street legal.