Land Access and Easements
The legal basis for determining questions of public prescriptive easements and other bases for rights to land access and use, focus in part on questions of where roads or routes originate and terminate, whether they are maintained or improved, and the frequency and intensity of their use, and interruptions in their use, through time. Witnesses are often unable to remember exactly when they have used routes or properties, or even just what access routes they used.
Historic aerial photographs provide a valuable resource by which access routes to a property - as well as possible property modification and uses - can be accurately mapped, and their nature and intensity of use through time can be assessed. First, historic aerial photos must be located; optical and digital stereo photointerpretation and mapping methods are then used to inspect their details and register these through time in a unified map database. Although these technologies allow details of roads and routes to be easily seen in many instances, their interpretation is not necessarily straightforward, and consideration of the dynamics of the environment, human transport and human land-use behavior, and comparison of the appearance of the various roads and routes within a region are necessary as well.