Grade Separated Intersection Geocoding with MultiNet

[DavidFurtney]

For a dispatch application, we want our users to be able to geocode "virtual" (grade separated crossing) intersections like
W 6th Ave & Bryant St, Denver, CO 80204 
With the Dynamap data format, this was working fine, but with MultiNet it is not.  The difference is that Dynamap had junctions at the grade separated crossings and MultiNet does not.  In order to geocode intersecterions, the geocoder appears to need a set of overlapping junctions to be present.   The planarize tool / API comes tantalizingly close to doing what we need, but has two serious defects.   It removes duplicate feature lines (which are used as alternate road names by the geocoder) and it fails to break address numbering based on the lengths of the planarized segments.  The road maps are in the most current MultiNet shapefile format and we currently have an ArcView 9.3.1 geoprocessing environment. I am looking for ideas on how to geoprocess the MultiNet GC layer into the form we need.   All options are open, buying it or building it.  If we build this tool, I am looking for pointers on how to do that efficiently. 

Ideas?

[DavidFurtney]

Rephrasing:

What geoprocessing steps would transform a road layer in which roads at different Z levels (grade separated) do not have junctions where those roads intersect to one in which the roads are split so that they do? 

Additionally, what steps would be needed to fix the house number attributes between the split segments?  For example, before split, the road segment has LF=100, LT=198, RF=101, RT=199 to after split (based on length): LF1=100, LT1=138, RF1=101, RT1=139 and LF2=140, LT1=141, RF1=198, RT1=199.