Very distinct accents and dialect in my area only 5 miles apart up to about 20 years ago. Hull/Beverley/Rural East Riding, 3 very different dialects/accents, and yet there has been definitely an evening out of accent along the M62 corridor, about a 100 miles. Manchester, Bradford, Leeds, Goole, Hull. There are those who don't get out much who cling to the old accents, Goole=South Yorkshire, Bratfort. Scouse of course still very distinct.