Often you think that even before the railways, most people travelled across land to do long journeys. I guess it depended. If a family from Co Durham in the mid 1700s wanted to move to London, I guess the quickest way was to go by sea. Go to Newcastle, Sunderland or another port, get a boat there down the east coast to London as opposed to clonking across land for days and having to stop at coach and horses houses.
In about 1780, my ancestors from Norwich in Norfolk moved to London. They may have gone by land, down past Cambridge towards Bethnal Green, along what is now the A11 and M11 but they may also have gone by sea, gone up the river Yare to Yarmouth (about 13 or 14 miles by river), then on from Great Yarmouth to London down past Suffolk and Essex into the Thames to London docks.
In about 1780, my ancestors from Norwich in Norfolk moved to London. They may have gone by land, down past Cambridge towards Bethnal Green, along what is now the A11 and M11 but they may also have gone by sea, gone up the river Yare to Yarmouth (about 13 or 14 miles by river), then on from Great Yarmouth to London down past Suffolk and Essex into the Thames to London docks.