It starts at Cleethorpes, then heads west into Grimsby. It turns south at Caistor, bypasses Market Rasen, then heads toward Lincoln. After Lincoln it starts following the route of the old Fosse Way, bar bypasses. It bypasses Newark-On-Trent, and continues south-west, passing the A52 near Bingham. As it enters Leicestershire, it is going nearly directly south. It bypasses Syston, disappears into Leicester's ring-road system, and then vanishes, to reappear somewhere to the east of Coventry. (The Fosse Way has been de-rated to be the B4455, which goes through Aylestone and Narborough).
From Coventry, it goes south-west near Kenilworth, north of Warwick, then bypasses Stratford-upon-Avon. It continues west, to Alcester, then sharply turns south and heads through Evesham, and vanishes again somewhere near Tewkesbury. It used to go to Bath.