MI Address Geocoding Difficulties

[Valdis J Kalnins]

Thanks to Jerry Howard and Marc Champagne for their insight.  However, it hasn't solved our problem since we are not using GDT Databases or StreetInfo.  Instead, we are trying to create out own address layer from based on some raw linework data provided by the Michigan Information Center.  After some further experimentation, it seems that the built-in MapInfo Geocoding function/algorithm operates as follows.   1.  It takes the middle node of a given line segment (irrespective of its location along the segment) and assigns it to the middle point of the address range (tested both 100 and 200 addresses per segment).   2.  It then calculates the distance between this middle node and each end (these distances are not necessarily the same length).   3.  Each address is then distributed as a multiple of each "half-segment" length with a decreasing distance towards the end points.   4.  The decreasing distance towards the end points is to ensure that address 1 (for example) doesn't fall in the middle of an intersecting road.  For cities, this works relatively well as the offset from the end of the block ranges from 15ft for a 100ft road segment to 140 feet for a 500ft segment.  However, in rural areas (most of our county) where intersections are typically every mile, the offsets end up being around 800ft. and corner houses are missed entirely.   Thus, it appears that if: You are address matching in a city; and Your nodes are evenly spaced along the segment or there are the same number of nodes on either side of the middle node; Then your addresses coding will match the real world.   These conditions seem very restrictive and awkward for our situation.   Can anyone confirm my findings from their own experience? Is there a way around this problem in MapInfo Pro 5.5 or 6.0? Is there an add-on that has a more robust location finding algorithm based on the entire length of the segment irrespective of node placement?   Regards, Valdis Kalnins Allegan County GIS, Michigan