Research Postar model Travel between ISBA areas

Coverage in a specific ISBA area may be boosted by people travelling in from another region.  Conversely, people in a region may see sites outside their “home” area in an adjoining region.  The travel survey is used to create an “import/export matrix”.  Passages are recorded for “home” and “away” as a percentage of all “home” passages.  

All passages outside the “home” region are then recorded in the relevant export region and are applied to each relevant region as an adjustment to its gross OTS.  The same is done for imported passages.  This means that a campaign restricted to one region will also deliver some audience in neighbouring areas and possibly even beyond.