In Britain, the A1 is a famous main road that runs from London in the south all the way north to Edinburgh in Scotland. British main roads have numbers; “A” roads are the important ones, and the A1 is the great north–south route, following in a loose way the old Great North Road. It is not a motorway for the whole trip. Some stretches are a faster motorway written A1(M), but much of it still goes through or past towns, with ordinary junctions and speed limits. You will see “A1” on UK maps and road signs. It is not the same road as the M1, which is a motorway that also leaves London heading north but is a different line. And though actually, English speakers also say “A1” to mean “excellent” — that is a different use of the same letters, not this road.