I don't see any problem in your data processing. You need to know how to summarize the field to get your result in your insected line feature class table.
Thank you. I can do the summary statistics but the problem is in the output from the intersect operation. There should not be as many line segements (in 100s of cases they are identical) assigned to each of the buffer polygons as there are. This must be a result of the overlap of the polygons, as it works fine when I use the layer with the contiguous, i.e. non-overlapping land use parcels. In the latter case I get for example 6 line segments if three network links intersect with the parcel (3*2 spatially coincident lines for each travel direction of each link; these are from the model network, hence they have exactly the same location; in the real world, these wold be seperate lanes).
Thank you. I can do the summary statistics but the problem is in the output from the intersect operation. There should not be as many line segements (in 100s of cases they are identical) assigned to each of the buffer polygons as there are. This must be a result of the overlap of the polygons, as it works fine when I use the layer with the contiguous, i.e. non-overlapping land use parcels. In the latter case I get for example 6 line segments if three network links intersect with the parcel (3*2 spatially coincident lines for each travel direction of each link; these are from the model network, hence they have exactly the same location; in the real world, these wold be seperate lanes).
This is exactly what intersect does with overlapping polygons, it creates 100s of slivers and duplicates. In essence to get each parcel clean you would have to iterate the set that overlaps one at a time against the clean road network. Time to process would be even longer, but results would be better at least as long as one parcel is not supposed to interact with any other parcel. A sample of a clean input parcel buffer against a clean network example would be useful showing what you really want the end product to be for that set of buffers. I.e. solve the problem as though only one property existed so I can see what you really expect to end up with. So assuming the non-overlapping case looks good to you, show that.
If the street street traffic emissions affect both side parcels, that the buffered parcels are overlapped is correct and fit to your puepose; you need to calculate the emissions distribution weight for each parcel (in other word they share that emissions).
If you only want assign this seg emissions for one parcel, you need to clean overlapped parcels or using another way to select one seg from overlapping lines.
Another thoughts:
1.Clean up the polygon layer first, to eliminate/clean up the gaps between adjcent parcels, overlapped parcel portions, sliver parcels.
2.Buffering the parcel (lot) outlines (one direction) instead of buffering the parcel polygons.
3. You can buffer street network lines instead of buffering parcels (one or two of line directions buffering), then convert the buffered polygons to lines, intersect those lines to parcel polygons.
4.Join the street network attribute data to the parcel layer by using address field, then convert parcel polygons to outlines, select that line closest to the street as target line for this parcel.