Travel to work area legal status. However, they give planners and geographers an alternate view of urban life as their boundaries are tied not to arbitrary administrative limits but socio-economic ties. Having an idea of where people commute from for work is particularly useful for public transport planning. Travel to Work Areas are defined by the Office for National Statistics using census data for commuting between wards, based on the different locations of individuals' home and work addresses. A Travel to Work Area is a collection of wards for which "of the resident economically active population, at least 75% actually work in the area,
Work (thermodynamics) energy as heat because of its non-mechanical nature. Another important kind of work is isochoric work, that is to say work that involves no eventual overall change of volume of the system between the initial and the final states of the process. Examples are friction on the surface of the system as in Rumford's experiment; shaft work such as in Joule's experiments; and slow vibrational action on the system that leaves its eventual volume unchanged, but involves friction within the system. Isochoric work for a body in its own state of internal thermodynamic equilibrium is done only by the surroundings