The Car Dyke is generally taken as the boundary of The Fens, though here, it heralds the more commercial part of the town. At once, the road passes the former works of BRM, the Formula One motor racing Constructors' Champion in 1962. The firm is gone but it has left an engineering tradition in the town. Shortly, the road turns north-eastwards, following the bank of the Roman artificial river across the fen, the Old Ea. At the edge of the town, it turns away from the now hidden river bed, almost eastwards across the black, humic soil of Bourne North Fen.(25) Here we begin to see The Fens as the region more typically is, a broad, nearly flat, agricultural land.