The A66 is a major road in Northern England, which in part follows the course of the Roman road from Scotch Corner to Penrith. It runs from east of Middlesbrough in the ceremonial county of North Yorkshire to Workington in Cumbria. It is anomalously numbered since west of Penrith it trespasses into numbering zone 5; this is because it originally terminated at the A6 in Penrith but was extended further west in order to create one continuous east–west route.