Merging two polylines (street networks)

Question

I have the following problem: I have two street datasets from completely different sources. I need some attributes from one dataset (red lines) to be joined into the other one (green lines). Until now I tried to make a buffer and afterwards join the green lines with the buffer...it worked, until I was facing some specific problem. The buffer does not always cover the green line in extreme situations and the attributes will be lost (see attached picture). Do you have any other ideas? I was working in PostGIS so far, but I am also open for other solutions.

Answer 1

I would try to find the nearest feature from the reference layer.

SELECT DISTINCT ON (a.id) a.id,  b.column1
FROM green a
-- find all the points you want to snap to within the given distance in units of crs
LEFT JOIN red b ON (ST_DWithin(a.wkb_geometry, b.wkb_geometry, 150))
-- order by distance (see spatal operators, mainly <#>, st_distance might be handy as well, though not that efficient)
ORDER BY id, a.wkb_geometry <-> b.wkb_geometry;

This way you can retrieve attributes of the nearest feature for every green line. Note that you might need to fiddle with ST_DWithin distance parameter a bit.