A literature survey was undertaken to identify all the various audio signing concepts which may have been investigated, under development, or already in use. A total of 13 systems are identified. Three of these are similar but not related to the automatic audio signing concept. Four systems are related to the automatic audio signing concept but did not have characteristics to be investigated under subsequent contract tasks. These systems are only briefly discussed. Six systems are reviewed in detail. These systems are the Autofahrer Rundfunk Information (ARI), CARFAX, Highway Advisory Information Radio (HAIR) Highway Advisory Radio (HAR), Protection of Automobilists and Aid to Circulation (PAAC) and Traffic Incident Information Systems (TIIS)
Samenvatting