The main priority of the BTC was to modernise its main-line railways and many of the uncompleted projects which were part of the New Works programme were postponed or shelved. These included plans to extend the Bakerloo line to Camberwell, and to extend the Northern line to Bushey Heath, linking up the separate branches terminating at Edgware and Mill Hill East in the process. However, this latter scheme (the Northern Heights) was never completed, as the protection of the countryside, under the newly created Green Belt plan, stopped residential building in this area and reduced passenger numbers would not justify the expenditure.