How do improvements to transport links reduce the north-south divide?

4 mark question, my minds gone blank! -.-

better transport links up north would see more trade coming in and being accessible, boosting its economy. It may also encourage workers from the south to live there as houses tend to be cheaper and this way they can still get to work; again boosting house prices through demand. This in turn may also see more businesses operate up north given trade is more accessible and a growing market. This way it'd reduce the north-south divide but bugger all to that