If you're driving from London, Cambridge (54 miles) is off M11. At Exit 9, M11 connects with A11 to Norwich (114 miles); A14 off A11 goes to Bury St. Edmunds. A12 from London goes through east Suffolk via Ipswich. For Lincoln (131 miles), take A1 via Huntingdon, Peterborough, and Grantham to A46 at Newark-on-Trent. A more scenic alternative is to leave A1 at Grantham and take A607 to Lincoln.
East Anglia has few fast main roads besides those mentioned here. Once off the A roads, traveling within the region often means taking country lanes that have many twists and turns. Going even just a few miles can take much longer than you think.