The planning policies expressed in the LDF deal with a wide range of local issues including promoting more energy efficient transport facilities, highway proposals and highway safety, ensuring an adequate supply of land for housing and other uses, safeguarding areas of countryside, and safeguarding important landscapes or sites of historic, ecological or scientific importance. More specific policies usually promote best practice in building design as a reflection of local traditions and priorities. The interests of sustainability are built into LDFs, not only in terms of energy efficiency, but also in promoting economic growth, regeneration, and the fostering of strong and inclusive communities. Whatever their local priorities, LDFs are a key policy document for all local authorities, enabling them and other local agencies to engage in spatial planning for their local area on an inclusive and "joined up" basis.