Not sure what the regulations are now , but back in the mid Sixties , the UK government stopped any Learner driver from riding a SOLO Motorcycle larger than 250cc .
However , WITH a sidecar , the ONLY restriction was that Motorways were off limits , but passengers could be carried
I was a serious Sidecar user , and was not affected by this change in the law , but was horrified at the thought that as the law stood , a Teenager could buy a BIG bike with a sidecar and carry any
of his friends who wanted to risk thir lives with him perfectly legally !