1. A method for determining a measure of curviness having a curved road portion configured for operation in a navigation system, the method comprising: determining location data for the curved road portion from map data retrieved from a map database; identifying points of inflection from the location data of the curved road portion; identifying at least one curved segment as road portions between the points of inflection; measuring a linear distance, L linear , between the points of inflection of the at least one curved segment; measuring a curve depth, H, by identifying the maximum distance between the line between the points of inflection and any point on the curved segment along a perpendicular to the line between points of inflection; calculating a curved segment degree of curviness=H/L linear ; and using the curved segment degree of curviness to determine the measure of curviness of the route.