Map data architecture for vehicle computer system

A data architecture for a motor vehicle that continuously provides updated data about paths along roads onto which the motor vehicle can travel from a current position of the motor vehicle as the motor vehicle travels along the roads. The data architecture uses a map database containing data about roads in a geographic region and a vehicle positioning program that uses data from sensors to provide an output indicating a current location along a road segment represented by data in the map database. The data architecture also includes a data horizon program that uses the output of the vehicle positioning program and data from the map database to determine one or more paths that the motor vehicle can travel extending from the current vehicle position to an extent associated with a threshold. Data representing the paths determined by the data horizon program are stored in a data repository from which driver assistance systems can obtain the data.