Arrangement for generating road information from stored digital map database has application unit implementing arc approximation logic that clears data outside defined window

摘要

A stored map database (42) has data defining roads on the route in the form of road segments, each with end points, an application unit (32) implements circular arc approximation logic to clear data defining selected road segments outside a defined window about a circle approximating to a bend in the road when operational. Sharp bend information is derived by comparing circles with defined radius values. An Independent claim is included for a method of generating road information.