A method for determining a responsible service area for a service request call, the service request call including a civic address indicating locus of origin of the service request call, includes: (a) accessing a geographic information system database relating to the locus of origin to identify a street line segment containing the civic address; (b) determining whether the street line segment is wholly contained within any polygon; (c) when the street line segment is wholly contained within a respective polygon, presenting the respective polygon as the responsible service area; and (d) when the street line segment is not wholly contained within the respective polygon, (1) recording a data deficiency identifying the non-containment as a polygon-segment error, (2) determining an estimated locus of the civic address on the street line segment in a resulting polygon containing the estimated locus, and (3) presenting the resulting polygon as the responsible service area.